After completing my fellowship at Stanford, my research has predominantly focused on refining preventive and therapeutic strategies for managing patients with postpartum hemorrhage. Overlapping research interests include: investigations of point-of-care devices for assessing maternal hematologic and coagulation profiles. I have also performed large population-wide studies examining: modes of obstetric anesthesia and analgesia, and maternal morbidity during and after delivery.

Clinical Focus

  • Anesthesia
  • Obstetric Anesthesia
  • Outcomes Research
  • Outcomes, Pregnancy

Academic Appointments

Honors & Awards

  • Child Health Research Institute Grant (CHRI), Lucile Packard Childrens Hospital (2015)
  • Mentored Patient-Oriented Research Career Development Award (K23), NICHD, NIH (2013)
  • Gerard W. Ostheimer Lecture: 'What's New in Obstetrics -2011?', Annual Meeting of the Society of Obstetric Anesthesia and Perinatology (2012)
  • Outstanding Interdepartmental Faculty Professor, Department of Obstetrics and Gynecology, Stanford University School of Medicine (2011)
  • Gertie Marx Award (1st prize), Society of Obstetric Anesthesia and Perinatology (SOAP) (2006)

Boards, Advisory Committees, Professional Organizations

  • Host of Annual Meeting for the Society for Obstetric Anesthesia and Perinatology, Society for Obstetric Anesthesia and Perinatology (2016 - Present)
  • Member of the Associate Editorial Board, BMC Pregnancy and Childbirth (2014 - Present)
  • Member of the Associate Editorial Board, International Journal of Obstetric Anesthesia (2013 - Present)
  • Member, Child Health Research Institute, Stanford University School of Medicine (2012 - Present)
  • Member of the Education Committee, Society for Obstetric Anesthesia and Perinatology (2012 - Present)

Professional Education

  • Board Certification: Anesthesia, The Royal College of Anaesthetists
  • Medical Education:St George's Hospital Medical School (1997) England
  • FRCA, Fellow of the Royal College of Anaesthetists, UK, Anesthesiology (2003)
  • Residency:South Thames West - St George's School of Anaesthesia (2004) UK
  • Fellowship:Stanford University School of Medicine (2006) CA
  • M.S., Department of Health Research and Policy, Stanford University, Epidemiology (2011)

Research & Scholarship

Current Research and Scholarly Interests

I am a clinician investigator with primary research interests in optimizing strategies to better prevent and treat postpartum hemorrhage, a condition which is a leading cause of maternal morbidity and mortality. Integrating a background in clinical epidemiology and clinical research, the overarching goal of my current research is to develop and validate clinical prediction rules which will ultimately aid health-care providers in identifying patients at risk of obstetric morbidity secondary to postpartum hemorrhage. I have also led investigations investigating the clinical utility of point-of-care devices for the assessment of the maternal hematologic and hemostatic profiles. These devices offer the potential to provide real-time and continuous data to assist physicians who manage patients with life-threatening obstetric hemorrhage. For prior and ongoing work, I have received institutional and industry funding for clinical trials in obstetrics, and I am previously been a recipient of federal funding (K23) from the National Institute of Health.

Clinical Trials

  • Oxytocin Infusions and Blood Loss in Patients Undergoing Elective Cesarean Delivery. Not Recruiting

    Although prior dose-finding studies have investigated the optimal bolus dose of oxytocin to initiate adequate uterine tone, it is unclear what oxytocin infusion regimen is required to maintain adequate uterine tone after delivery. The study investigators aim to compare two different infusion rates of oxytocin to assess the optimal infusion regimen for reducing blood loss in women undergoing elective Cesarean delivery.

    Stanford is currently not accepting patients for this trial. For more information, please contact Alexander J Butwick, F.R.C.A, 650-736-8513.

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  • Blood Loss Measurement During Cesarean Delivery Not Recruiting

    The aim of this study is to assess the ability of the Triton Device to measure blood loss among women undergoing elective and non-elective cesarean delivery. This patient population often experiences significant blood loss during surgery, and measurements of surgical blood loss are often inaccurate.

    Stanford is currently not accepting patients for this trial.

    View full details

  • Thromboelastography to Assess Age-Related Coagulation Differences in Patients Undergoing Cesarean Delivery Not Recruiting

    The purpose of the study is to assess potential age-related differences on coagulation profile of patients undergoing Cesarean Section, using thromboelastography (TEG). The investigators will compare coagulation data collected from the study to assess potential differences in coagulation parameters for the following age groups: (i) women less than 35 yrs (ii) women 35 yrs or older.

    Stanford is currently not accepting patients for this trial. For more information, please contact Alexander J Butwick, MBBS, FRCA, 650-736-8513.

    View full details


2018-19 Courses


All Publications

  • Oral versus intravenous iron therapy for postpartum anemia: A systematic review and meta-analysis. American journal of obstetrics and gynecology Sultan, P., Bampoe, S., Shah, R., Guo, N., Estes, J., Stave, C., Goodnough, T., Halpern, S., Butwick, A. J. 2018


    OBJECTIVE: To perform a systematic review of randomized trials comparing oral versus intravenous iron therapy to treat postpartum anemia.DATA SOURCES: Data sources were: PubMed (1972-2017); Cochrane Central Register of Controlled Trials, CENTRAL (1972-2017); CINAHL (1972-2017); Web of Science; Excerpta Medica Database, and EMBASE (1972-2017).STUDY ELIGIBILITY CRITERIA: We included randomized trials comparing oral versus intravenous iron monotherapy to treat postpartum anemia (classified as a hemoglobin<12 g/dL).STUDY APPRAISAL AND SYNTHESIS METHODS: Study quality was assessed with the Cochrane risk of bias assessment tool. The primary outcome was the hemoglobin concentration at 6 weeks postpartum. Secondary outcomes included: hemoglobin concentration at 1 - 5 weeks postpartum, ferritin concentration at 1 - 6 weeks postpartum; and maternal adverse outcomes. For meta-analysis, mean differences and odds ratios using a random effects model were calculated. Risk of heterogeneity was reported as I2.RESULTS: Fifteen randomized trials met our inclusion criteria (n=1,001 and 1,181 women receiving oral iron and intravenous iron, respectively); 4 studies reported data for our primary outcome. We observed higher postpartum week 6 hemoglobin concentrations in the iv iron group compared to the oral iron group, (mean difference 0.9 g/dL, 95% CI=0.4, 1.3; p=0.0003). Compared to oral iron, women receiving iv iron had higher hemoglobin concentrations at postpartum weeks 1, 2, and 3; higher ferritin concentrations at postpartum weeks 1, 2, 4, and 6; an increased likelihood of skin flushing (odds ratio=6.95; 95% confidence interval, 1.56-31.03; P=0.01; I2=0%); and a decreased likelihood of constipation (odds ratio=0.08, 95% confidence interval, 0.03-0.21; P=<0.00001, I2=27%) and dyspepsia (odds ratio=0.07, 95% confidence interval, 0.01-0.42; P=0.004; I2=0%). The reported event rate for anaphylaxis among women receiving intravenous iron was 0.6%.CONCLUSIONS: In this systematic review, among women with postpartum anemia, hemoglobin concentrations at 6 weeks postpartum were almost 1 g/dL higher in women who received intravenous iron compared to oral iron. The safety profile of intravenous iron was also reassuring. Given the weaker hemoglobin response and higher risk of gastrointestinal side-effects with oral iron use, our findings suggest that intravenous iron be considered as a viable treatment option for postpartum iron deficiency anemia.

    View details for DOI 10.1016/j.ajog.2018.12.016

    View details for PubMedID 30578747

  • Prepregnancy maternal body mass index and venous thromboembolism: A population based cohort study. BJOG : an international journal of obstetrics and gynaecology Butwick, A. J., Bentley, J., Leonard, S. A., Carmichael, S. L., El-Sayed, Y. Y., Stephansson, O., Guo, N. 2018


    OBJECTIVE: To assess the relationship between maternal body mass index (BMI) and pregnancy-related venous thromboembolism (VTE).DESIGN: Cross-sectional study.SETTING & POPULATION: 2,449,133 women with singleton pregnancies who underwent delivery hospitalization in California between 2008 and 2012.METHODS: Association of prepregnancy BMI and the risk of an antepartum and postpartum VTE was examined using logistic regression, with normal BMI as reference.MAIN OUTCOME MEASURES: Antepartum and postpartum VTE related hospitalization.RESULTS: The prevalences of antepartum and postpartum VTE increased with increasing BMI (antepartum: 2.3, 3.0, 3.8, 4.2, 4.7, and 10.6 per 10 000 women for underweight, normal BMI, overweight, obesity class I, II, and III, P<0.001. postpartum: 2.0, 3.1, 3.9, 5.6, 9.0, and 13.2 per 10 000 women, P<0.01). The adjusted odds of antepartum and postpartum VTE increased progressively with increasing BMI, and obese class III women being at highest risk of pregnancy-related VTE compared with normal BMI women: adjusted odds ratio (OR) for antepartum VTE: 2.9; 95% CI 2.2-3.8 and adjusted OR for postpartum VTE: 3.6; 95% CI 2.9-4.6.CONCLUSIONS: Our findings clearly demonstrate an increasing risk of pregnancy-related VTE with increasing BMI. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/1471-0528.15567

    View details for PubMedID 30500109

  • Maternal Body Mass Index and Use of Labor Neuraxial Analgesia: A Population-based Retrospective Cohort Study. Anesthesiology Butwick, A. J., Wong, C. A., Guo, N. 2018


    BACKGROUND: Neuraxial labor analgesia may benefit obese women by optimizing cardiorespiratory function and mitigating complications related to emergency general anesthesia. We hypothesized that obese women have a higher rate of neuraxial analgesia compared with nonobese parturients.METHODS: Using U.S. natality data, our cohort comprised 17,220,680 deliveries, which accounts for 61.5% of 28 million births in the United States between 2009 and 2015. We examined the relationships between body mass index class and neuraxial labor analgesia, adjusting for sociodemographic, antenatal, pregnancy, and peripartum factors.RESULTS: The study cohort comprised 17,220,680 women; 0.1% were underweight, 12.7% were normal body mass index, 37% were overweight, and 28.3%, 13.5%, and 8.4% were obesity class I, II, and III, respectively. Rates of neuraxial analgesia by body mass index class were as follows: underweight, 59.7% (9,030/15,128); normal body mass index, 68.1% (1,487,117/2,182,797); overweight, 70.3% (4,476,685/6,368,656); obesity class I, 71.8% (3,503,321/4,881,938); obesity class II, 73.4% (1,710,099/2,330,028); and obesity class III, 75.6% (1,089,668/1,442,133). Compared to women with normal body mass index, the likelihood of receiving neuraxial analgesia was slightly increased for overweight women (adjusted relative risk, 1.02; 95% CI, 1.02 to 1.02), obese class I (adjusted relative risk, 1.04; 95% CI, 1.04 to 1.04), obese class II (adjusted relative risk, 1.05; 95% CI, 1.05 to 1.05), and obese class III (adjusted relative risk, 1.06; 95% CI, 1.06 to 1.06).CONCLUSIONS: Our findings suggest that the likelihood of receiving neuraxial analgesia is only marginally increased for morbidly obese women compared to women with normal body mass index.

    View details for DOI 10.1097/ALN.0000000000002322

    View details for PubMedID 29939847

  • Assessing the Association Between Blood Loss and Postoperative Hemoglobin After Cesarean Delivery: A Prospective Study of 4 Blood Loss Measurement Modalities. Anesthesia and analgesia Fedoruk, K., Seligman, K. M., Carvalho, B., Butwick, A. J. 2018


    BACKGROUND: Visual estimation and gravimetric methods are commonly used to quantify the volume of blood loss during cesarean delivery (CD). However, the correlation between blood loss and post-CD hemoglobin (Hb) is poorly studied, and it is unclear whether the correlation varies according to how blood loss is measured.METHODS: After obtaining Institutional Review Board approval, we performed a prospective study of 61 women undergoing CD to assess the relations between post-CD Hb and blood loss measured using 4 modalities: gravimetric blood loss measurement (gBL), visual blood loss estimation by a blinded obstetrician (oBL) and anesthesiologist (aBL), and the Triton System (tBL). Hb was measured preoperatively and within 10 minutes after CD. gBL was quantified as blood volume in a suction canister in addition to the weight of blood-soaked sponges. tBL was measured with the Triton System by photographing blood-soaked sponges and suction canister contents. To assess the relation between blood loss and post-CD Hb, we performed correlation analyses and compared the magnitude of the correlations across the 4 measurement modalities using William t test. A Bonferroni correction was set to identify a statistically significant correlation (P < .0125) and statistically significant differences between correlation coefficients (P < .008).RESULTS: The mean (standard deviation) preoperative Hb was 12 (1.1) g/dL and post-CD Hb was 11.3 (1.0) g/dL. Median (interquartile range) values for gBL, oBL, aBL, and tBL were 672 mL (266-970), 700 mL (600-800), 750 mL (600-1000), and 496 mL (374-729), respectively. A statistically significant but weak correlation was observed between tBL and post-CD Hb (r = -0.33; P = .01). No statistically significant correlations were observed among aBL (r = -0.25; P = .06), oBL (r = -0.2; P = .13), and gBL (r = -0.3; P = .03) with post-CD Hb. We did not detect any significant differences between any 2 correlation coefficients across the 4 modalities.CONCLUSIONS: Given that we observed only weak correlations between each modality with post-CD Hb and no significant differences in the magnitude of the correlations across the 4 modalities, there may be limited clinical utility in estimating post-CD Hb from blood loss values measured with any of the 4 modalities.

    View details for DOI 10.1213/ANE.0000000000003449

    View details for PubMedID 29847380

  • Effect of Maternal Body Mass Index on Postpartum Hemorrhage. Anesthesiology Butwick, A. J., Abreo, A., Bateman, B. T., Lee, H. C., El-Sayed, Y. Y., Stephansson, O., Flood, P. 2018


    It is unclear whether obesity is a risk factor for postpartum hemorrhage. The authors hypothesized that obese women are at greater risk of hemorrhage than women with a normal body mass index.The authors conducted a cohort study of women who underwent delivery hospitalization in California between 2008 and 2012. Using multilevel regression, the authors examined the relationships between body mass index with hemorrhage (primary outcome), atonic hemorrhage, and severe hemorrhage (secondary outcomes). Stratified analyses were performed according to delivery mode.The absolute event rate for hemorrhage was 60,604/2,176,673 (2.8%). In this cohort, 4% of women were underweight, 49.1% of women were normal body mass index, 25.9% of women were overweight, and 12.7%, 5.2%, and 3.1% of women were in obesity class I, II, and III, respectively. Compared to normal body mass index women, the odds of hemorrhage and atonic hemorrhage were modestly increased for overweight women (hemorrhage: adjusted odds ratio [aOR], 1.06; 99% CI, 1.04 to 1.08; atonic hemorrhage: aOR, 1.07; 99% CI, 1.05 to 1.09) and obesity class I (hemorrhage: aOR, 1.08; 99% CI, 1.05 to 1.11; atonic hemorrhage; aOR, 1.11; 99% CI, 1.08 to 1.15). After vaginal delivery, overweight and obese women had up to 19% increased odds of hemorrhage or atonic hemorrhage; whereas, after cesarean delivery, women in any obesity class had up to 14% decreased odds of severe hemorrhage.The authors' findings suggest that, at most, maternal obesity has a modest effect on hemorrhage risk. The direction of the association between hemorrhage and body mass index may differ by delivery mode.

    View details for DOI 10.1097/ALN.0000000000002082

    View details for PubMedID 29346134

  • Prevalence of Depression Among Women of Reproductive Age in the United States. Obstetrics and gynecology Guo, N., Robakis, T., Miller, C., Butwick, A. 2018


    To describe the prevalence, use of antidepressants, and predictors of major and minor depression among nonpregnant women of childbearing age.Using data from the National Health and Nutrition Examination Surveys 2007-2014, we performed a cross-sectional study of 3,705 nonpregnant women of childbearing age. The primary outcome is the prevalence of major depression, and secondary outcomes are the prevalence of minor depression, rates of antidepressant use, and predictors of major and minor depression. Major and minor depression were classified using the Patient Health Questionnaire 9. Univariate and multivariate associations between major depression and minor depression with potential predictors were estimated using multinomial logistic regression.The overall prevalences of major and minor depression were 4.8% (95% CI 4.0-5.7%) and 4.3% (95% CI 3.5-5.2%), respectively. The prevalences of antidepressant use among women with major depression and minor depression were 32.4% (95% CI 25.3-40.4%) and 20.0% (95% CI 12.9-29.7%), respectively. Factors most strongly associated with major depression were government insurance (adjusted relative risk [RR] ratio 2.49, 95% CI 1.56-3.96) and hypertension (adjusted RR 2.09, 95% CI 1.25-3.50); for minor depression, these were education less than high school (adjusted RR 4.34, 95% CI 2.09-9.01) or high school education (adjusted RR 2.92, 95% CI 1.35-6.31).Our analysis indicates that 1 in 20 nonpregnant women of childbearing age experience major depression. Antidepressants are used by one third of those with major depression and one fifth of those with minor depression.

    View details for DOI 10.1097/AOG.0000000000002535

    View details for PubMedID 29528926

  • Mode of anaesthesia for Caesarean delivery and maternal morbidity: can we overcome confounding by indication? British journal of anaesthesia Butwick, A. J., Palanisamy, A. 2018; 120 (4): 621–23

    View details for DOI 10.1016/j.bja.2018.01.002

    View details for PubMedID 29576102

  • Accuracy of international classification of diseases, ninth revision, codes for postpartum hemorrhage among women undergoing cesarean delivery. Transfusion Butwick, A. J., Walsh, E. M., Kuzniewicz, M., Li, S. X., Escobar, G. J. 2018


    Determining the accuracy of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes for postpartum hemorrhage (PPH) is vital for reaching valid conclusions about the epidemiology of PPH. Our primary objectives were to assess the performance characteristics of ICD-9 PPH codes against a reference standard using estimated blood loss (EBL) among a cohort undergoing Cesarean delivery.We analyzed maternal discharge and EBL data from women who underwent Cesarean delivery at Kaiser Permanente Northern California facilities between 2010 and 2013. We defined PPH as an EBL of at least 1000 mL. In a secondary analysis, ICD-9 performance characteristics were assessed using an EBL of at least 1500 mL to classify severe PPH.We identified 35,614 hospitalizations for Cesarean delivery. Using EBL of at least 1000 mL as the "gold standard," PPH codes had a sensitivity of 27.8%, specificity of 97%, positive predictive value (PPV) of 74.5%, and a negative predictive value (NPV) of 80.9%. The prevalence of a PPH code (9%) was lower than the prevalence using a blood loss of at least 1000 mL (24%). Using a reference standard of EBL of at least 1500 mL, PPH codes had a sensitivity of 61.7%, specificity of 93.8%, PPV of 34.2%, and NPV of 97.9%.PPH ICD-9 codes have high specificity, moderately high PPVs and NPVs, and low sensitivity. An EBL of at least 1500 mL as a reference standard has higher sensitivity. Our findings suggest that, for women undergoing Cesarean delivery, quality improvement efforts are needed to enhance PPH ICD-9 coding accuracy in administrative data sets.

    View details for DOI 10.1111/trf.14498

    View details for PubMedID 29377131

  • Tranexamic Acid for the Management of Obstetric Hemorrhage OBSTETRICS AND GYNECOLOGY Butwick, A. J., Deneux-Tharaux, C., Sentilhes, L. 2017; 130 (6): 1386
  • Risk Factors for Severe Postpartum Hemorrhage After Cesarean Delivery: Case-Control Studies. Anesthesia and analgesia Butwick, A. J., Ramachandran, B., Hegde, P., Riley, E. T., El-Sayed, Y. Y., Nelson, L. M. 2017


    Women who undergo intrapartum caesarean delivery (CD) are at increased risk of postpartum hemorrhage (PPH) compared with those undergoing prelabor CD. To determine whether the presence and strength of the associations between individual risk factors and severe PPH vary among women undergoing prelabor CD or intrapartum CD, stratified analyses are needed according to CD subtype.To identify risk factors for severe PPH within 2 distinct CD populations, prelabor CD and intrapartum CD, we performed 2 case-control studies. Women in each study cohort delivered at a tertiary obstetric center in the United States between 2002 and 2012. For each study, cases were women who had a blood loss ≥1500 mL or who received an intraoperative or postoperative transfusion up to 48 hours after delivery. Risk factors for severe PPH among women undergoing prelabor CD or intrapartum CD were examined in separate logistic regression models.For prelabor CD, we identified 269 cases and 550 controls. Clinical factors with the highest adjusted odds for severe PPH during prelabor CD were general anesthesia (adjusted odds ratio [aOR] = 22.3; 95% confidence interval [CI] = 4.9-99.9; reference group = spinal anesthesia), multiple pregnancies (aOR = 8.0; 95% CI = 4.2-15.0; reference group = singleton pregnancy), and placenta previa (aOR = 6.3; 95% CI = 3.4-11.8). For intrapartum CD, we identified 278 cases and 572 controls. Clinical factors with the highest adjusted odds for severe PPH during intrapartum CD were general anesthesia (aOR = 5.4; 95% CI = 1.7-17.1), multiple pregnancies (aOR = 3.2; 95% CI = 1.7-6.3), and a predelivery hemoglobin ≤ 9.9 g/dL (aOR = 3.0; 95% CI = 1.3-6.9; reference group = predelivery hemoglobin ≥ 11 g/dL).Women who undergo prelabor CD and intrapartum CD have several shared risk factors for severe PPH (general anesthesia and multiple pregnancies). However, the risk factor profiles for severe PPH differed between these CD cohorts. Recognizing these differences may be important when planning resources and interventions for high-risk patients undergoing either prelabor or intrapartum CD.

    View details for DOI 10.1213/ANE.0000000000001962

    View details for PubMedID 28277324

  • Effect of a High-Rate Versus a Low-Rate Oxytocin Infusion for Maintaining Uterine Contractility During Elective Cesarean Delivery: A Prospective Randomized Clinical Trial. Anesthesia and analgesia Duffield, A., McKenzie, C., Carvalho, B., Ramachandran, B., Yin, V., El-Sayed, Y. Y., Riley, E. T., Butwick, A. J. 2017; 124 (3): 857-862


    Oxytocin is routinely used as prophylaxis against uterine atony. During elective cesarean delivery (CD), an oxytocin bolus is used to initiate adequate uterine tone, followed by an oxytocin infusion to maintain uterine contractility. However, it is unclear whether oxytocin maintenance infusion rate influences total estimated blood loss (EBL).We performed a prospective, randomized, double-blind trial in 51 women undergoing elective CD. Women were randomly assigned to receive an oxytocin maintenance infusion of 2.5 or 15 U/h. All women received an oxytocin 1 U bolus to initiate adequate uterine tone. The primary outcome was EBL. EBL values between groups were compared using a Mann-Whitney U test; P < .05 as statistically significant. The median EBL difference with 95% confidence intervals was also calculated. Secondary outcomes included adequacy of uterine tone, use of additional uterotonics, and oxytocin-related side effects, including hypotension.Of 51 women, 24 received a low-rate infusion and 27 received a high-rate infusion. Median (interquartile range) EBL values in the low-rate and high-rate groups were 634 (340-886) mL versus 512 (405-740) mL, respectively (P = .7). The median difference in EBL between groups was 22 mL; 95% confidence interval = -158 to 236 mL. The rate of postpartum hemorrhage did not differ between groups (low-rate group: 4/24 [16.7%] versus high-rate group: 4/26 [15.4%]). There were no between-group differences over time (first 20 minutes after commencing infusion) in the incidence of adequate uterine tone (P = .72) or hypotension (P = .32).Among women undergoing elective CD receiving an oxytocin maintenance infusion, EBL and uterine tone did not differ between women receiving 2.5 U/h oxytocin and those receiving 15 U/h oxytocin. Our findings suggest that efficacy can be obtained with a low oxytocin maintenance infusion rate; however, dose-finding studies are needed to determine the infusion rate that optimizes drug efficacy while minimizing side effects.

    View details for DOI 10.1213/ANE.0000000000001658

    View details for PubMedID 28212181

    View details for PubMedCentralID PMC5319709

  • Postpartum hemorrhage following vaginal delivery: risk factors and maternal outcomes. Journal of perinatology Miller, C. M., Cohn, S., Akdagli, S., Carvalho, B., Blumenfeld, Y. J., Butwick, A. J. 2017; 37 (3): 243-248


    Limited understanding of risk factors exists for postpartum hemorrhage (PPH) post-vaginal delivery. The aim of this study was to identify risk factors for PPH post-vaginal delivery within a contemporary obstetric cohort.Retrospective case-control study. PPH was classified by an estimated blood loss ⩾500 ml. Risk factors for PPH were identified using univariable and multivariable logistic regression. We secondarily investigated maternal outcomes and medical and surgical interventions for PPH management.The study cohort comprised 159 cases and 318 controls. Compared with a second-stage duration <2 h, a second stage⩾3 h was associated with PPH (adjusted odds ratio=2.3; 95% CI=1.2 to 4.6). No other clinical or obstetric variables were identified as independent risk factors for PPH. Among cases, 4% received red blood cells and 1% required intensive care admission.Although PPH-related morbidity may be uncommon after vaginal delivery, PPH should be anticipated for women after a second stage ⩾3 h.

    View details for DOI 10.1038/jp.2016.225

    View details for PubMedID 27977018

  • Improving post-caesarean analgesia: Where to next? BJOG : an international journal of obstetrics and gynaecology Butwick, A. 2017


    The provision of effective pain relief to mothers after caesarean section (CS) is a priority for both obstetric and anaesthesia providers. To meet this goal, multimodal analgesic regimens have been endorsed to manage pain and reduce opioid requirements after CS. Post-CS, typical oral analgesic regimens may comprise paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), and an oral opioid. The inclusion of paracetamol and NSAIDs is important as each drug has an opioid sparing effect, thereby reducing the incidence of opioid related side-effects. We know less about the best method to administer analgesics to mothers after CS. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/1471-0528.14597

    View details for PubMedID 28178769

  • Clinical and microbiological features of maternal sepsis: a retrospective study INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Abir, G., Akdagli, S., Butwick, A., Carvalho, B. 2017; 29: 26-33
  • Comparative Effectiveness of Lower Leg Compression Devices Versus Sequential Compression Devices to Prevent Postspinal Hypotension During Cesarean Delivery. Anesthesia and analgesia Carvalho, B., Zheng, L. L., Butwick, A. 2017; 124 (2): 696–97

    View details for DOI 10.1213/ANE.0000000000001750

    View details for PubMedID 28098691

  • Patterns and predictors of severe postpartum anemia after Cesarean section TRANSFUSION Butwick, A. J., Walsh, E. M., Kuzniewicz, M., Li, S. X., Escobar, G. J. 2017; 57 (1): 36-44

    View details for DOI 10.1111/trf.13815

    View details for Web of Science ID 000394428500008

  • Postcesarean delivery analgesia. Best practice & research. Clinical anaesthesiology Carvalho, B., Butwick, A. J. 2017; 31 (1): 69–79


    Effective pain management should be a key priority in women undergoing cesarean delivery. Suboptimal perioperative pain management is associated with chronic pain, greater opioid use, delayed functional recovery, impaired maternal-fetal bonding, and increased postpartum depression. Severe acute postoperative pain is also strongly associated with persistent pain after cesarean delivery. Multimodal analgesia is the core principle for cesarean delivery pain management. The use of neuraxial morphine and opioid-sparing adjuncts such as scheduled nonsteroidal anti-inflammatory medications and acetaminophen is recommended for all women undergoing cesarean delivery with neuraxial anesthesia unless contraindicated. Additional analgesic and opioid-sparing options such as wound instillation of local anesthetics, transversus abdominis plane blocks, dexamethasone, gabapentin, and ketamine may be used as appropriate in women at risk of severe postoperative pain or in women whose postoperative pain is not well controlled despite standard analgesic regimes.

    View details for DOI 10.1016/j.bpa.2017.01.003

    View details for PubMedID 28625307

  • Tranexamic Acid for the Management of Obstetric Hemorrhage. Obstetrics and gynecology Butwick, A. J., Deneux-Tharaux, C., Sentilhes, L. 2017; 130 (6): 1386

    View details for DOI 10.1097/AOG.0000000000002384

    View details for PubMedID 29189683

  • The Society for Obstetric Anesthesia and Perinatology Consensus Statement on the Anesthetic Management of Pregnant and Postpartum Women Receiving Thromboprophylaxis or Higher Dose Anticoagulants. Anesthesia and analgesia Leffert, L., Butwick, A., Carvalho, B., Arendt, K., Bates, S. M., Friedman, A., Horlocker, T., Houle, T., Landau, R., Dubois, H., Fernando, R., Houle, T., Kopp, S., Montgomery, D., Pellegrini, J., Smiley, R., Toledo, P. 2017


    Venous thromboembolism is recognized as a leading cause of maternal death in the United States. Thromboprophylaxis has been highlighted as a key preventive measure to reduce venous thromboembolism-related maternal deaths. However, the expanded use of thromboprophylaxis in obstetrics will have a major impact on the use and timing of neuraxial analgesia and anesthesia for women undergoing vaginal or cesarean delivery and other obstetric surgeries. Experts from the Society of Obstetric Anesthesia and Perinatology, the American Society of Regional Anesthesia, and hematology have collaborated to develop this comprehensive, pregnancy-specific consensus statement on neuraxial procedures in obstetric patients receiving thromboprophylaxis or higher dose anticoagulants. To date, none of the existing anesthesia societies' recommendations have weighed the potential risks of neuraxial procedures in the presence of thromboprophylaxis, with the competing risks of general anesthesia with a potentially difficult airway, or maternal or fetal harm from avoidance or delayed neuraxial anesthesia. Furthermore, existing guidelines have not integrated the pharmacokinetics and pharmacodynamics of anticoagulants in the obstetric population.The goal of this consensus statement is to provide a practical guide of how to appropriately identify, prepare, and manage pregnant women receiving thromboprophylaxis or higher dose anticoagulants during the ante-, intra-, and postpartum periods. The tactics to facilitate multidisciplinary communication, evidence-based pharmacokinetic and spinal epidural hematoma data, and Decision Aids should help inform risk-benefit discussions with patients and facilitate shared decision making.

    View details for DOI 10.1213/ANE.0000000000002530

    View details for PubMedID 29099429

  • Obstetric interventions and maternal morbidity among women who experience severe postpartum hemorrhage during cesarean delivery. International journal of obstetric anesthesia Seligman, K., Ramachandran, B., Hegde, P., Riley, E. T., El-Sayed, Y. Y., Nelson, L. M., Butwick, A. J. 2017; 31: 27–36


    Compared to vaginal delivery, women undergoing cesarean delivery are at increased risk of postpartum hemorrhage. Management approaches may differ between those undergoing prelabor cesarean delivery compared to intrapartum cesarean delivery. We examined surgical interventions, blood component use, and maternal outcomes among those experiencing severe postpartum hemorrhage within the two distinct cesarean delivery cohorts.We performed secondary analyses of data from two cohorts who underwent prelabor cesarean delivery or intrapartum cesarean delivery at a tertiary obstetric center in the United States between 2002 and 2012. Severe postpartum hemorrhage was classified as an estimated blood loss ≥1500mL or receipt of a red blood cell transfusion up to 48h post-cesarean delivery. We examined blood component use, medical and surgical interventions and maternal outcomes.The prelabor cohort comprised 269 women and the intrapartum cohort comprised 278 women. In the prelabor cohort, one third of women received red blood cells intraoperatively or postoperatively, respectively. In the intrapartum cohort, 18% women received red blood cells intraoperatively vs. 44% postoperatively (P<0.001). In the prelabor and intrapartum cohorts, methylergonovine was the most common second-line uterotonic (33% and 43%, respectively). Women undergoing prelabor cesarean delivery had the highest rates of morbidity, with 18% requiring hysterectomy and 16% requiring intensive care admission.Our findings provide a snapshot of contemporary transfusion and surgical practices for severe postpartum hemorrhage management during cesarean delivery. To determine optimal transfusion and management practices in this setting, large pragmatic studies are needed.

    View details for DOI 10.1016/j.ijoa.2017.03.009

    View details for PubMedID 28676403

    View details for PubMedCentralID PMC5578415

  • Nitrous oxide for labor analgesia: Utilization and predictors of conversion to neuraxial analgesia. Journal of clinical anesthesia Sutton, C. D., Butwick, A. J., Riley, E. T., Carvalho, B. 2017; 40: 40–45


    We examined the characteristics of women who choose nitrous oxide for labor analgesia and identified factors that predict conversion from nitrous oxide to labor neuraxial analgesia.Retrospective descriptive study.Labor and Delivery Ward.146 pregnant women who used nitrous oxide for analgesia during labor and delivery between September 2014 and September 2015.Chart review only.Demographic, obstetric, and intrapartum characteristics of women using nitrous oxide were examined. Multivariable logistic regression was performed to identify factors associated with conversion from nitrous oxide to neuraxial analgesia. Data are presented as n (%), median [IQR], adjusted relative risk (aRR), and 95% confidence intervals (CI) as appropriate.During the study period, 146 women used nitrous oxide for labor analgesia (accounting for 3% of the total deliveries). The majority (71.9%) of women who used nitrous oxide were nulliparous, and over half (51.9%) had expressed an initial preference for "nonmedical birth." The conversion rate to neuraxial blockade was 63.2%, compared to a concurrent institutional rate of 85.1% in women who did not use nitrous oxide. Factors associated with conversion from nitrous oxide to neuraxial blockade were labor induction (aRR=2.0, CI 1.2-3.3) and labor augmentation (aRR=1.7, CI 1.0-2.9).Only a small number of women opted to use nitrous oxide during labor, analgesia was minimal, and most converted to neuraxial analgesia. Women with induced and augmented labors should be counseled about the increased likelihood that they will convert to neuraxial analgesia.

    View details for DOI 10.1016/j.jclinane.2017.04.005

    View details for PubMedID 28625444

  • Neuraxial Anesthesia in Obstetric Patients Receiving Thromboprophylaxis With Unfractionated or Low-Molecular-Weight Heparin: A Systematic Review of Spinal Epidural Hematoma. Anesthesia and analgesia Leffert, L. R., Dubois, H. M., Butwick, A. J., Carvalho, B., Houle, T. T., Landau, R. 2017; 125 (1): 223–31


    Venous thromboembolism remains a major source of morbidity and mortality in obstetrics with an incidence of 29.8/100,000 vaginal delivery hospitalizations; cesarean delivery confers a 4-fold increased risk of thromboembolism when compared with vaginal delivery. Revised national guidelines now stipulate that the majority of women delivering via cesarean and women at risk for ante- or postpartum venous thromboembolism receive mechanical or pharmacological thromboprophylaxis. This practice change has important implications for obstetric anesthesiologists concerned about the risk of spinal epidural hematoma (SEH) among anticoagulated women receiving neuraxial anesthesia. We conducted a systematic review of published English language studies (1952-2016) and of the US Anesthesia Closed Claims Project Database (1990-2013) to identify cases of SEH associated with neuraxial anesthesia and thromboprophylaxis. We also report on SEH in obstetric patients receiving thromboprophylaxis and neuraxial anesthesia without adherence to the American Society of Regional Anesthesia (ASRA) recommendations. In our review, we initially identified 736 publications of which 10 met inclusion criteria; these were combined with the 5 cases of SEH identified in 546 obstetric Anesthesia Closed Claims reviews. None of these publications revealed SEH associated with neuraxial anesthesia and thromboprophylaxis with unfractionated heparin or low-molecular-weight heparin in obstetric patients. Based on data from 6 reports, 28 parturients had their neuraxial blockade before the minimum ASRA recommended time interval between the last anticoagulant dose and the neuraxial procedure. Based on data from 2 reports, 52 parturients received neuraxial anesthesia without their low-molecular-weight heparin dose being discontinued during the intrapartum period. Although the very low level of evidence and high heterogeneity in these reports make it difficult to draw quantitative conclusions from this systematic review, it is encouraging that this comprehensive search did not identify a single case of SEH in an obstetric patient receiving thromboprophylaxis and neuraxial anesthesia. Analysis of large-scale registries (eg, the Anesthesia Incident Reporting System of the Anesthesia Quality Institute) with more granular clinical and pharmacological data is needed to assess the impact of these practice changes on obstetric SEH incidence. In the interim, optimal care of obstetric patients depends on multidisciplinary planning of anticoagulation dosing to facilitate neuraxial anesthesia and thoughtful weighing of the relative risks and benefits of providing versus withholding neuraxial in favor of general anesthesia.

    View details for DOI 10.1213/ANE.0000000000002173

    View details for PubMedID 28628578

  • A Standardized Approach for Transfusion Medicine Support in Patients With Morbidly Adherent Placenta. Anesthesia and analgesia Panigrahi, A. K., Yeaton-Massey, A., Bakhtary, S., Andrews, J., Lyell, D. J., Butwick, A. J., Goodnough, L. T. 2017


    The incidence of placenta accreta (PA) has increased from 0.8 to 3.0 in 1000 pregnancies, driven by increased rates of cesarean deliveries (32.2% in 2014) of births in the United States. The average blood loss for a delivery complicated by PA ranges from 2000 to 5000 mL, frequently requiring substantial transfusion medicine support. We report our own institutional multidisciplinary approach for managing such patients, along with transfusion medicine outcomes, in this setting over a 5-year period.We reviewed records for patients referred to our program in placental disorders from July 1, 2009, to July 1, 2014. A placental disorders preoperative checklist was implemented to ensure optimal management of patients with peripartum hemorrhage.Of 136 patients whose placentas were reviewed postpartum, 21 had PA, 39 had microscopic PA, 17 had increta, 17 had percreta, and 42 had no accreta (of which 11 had placenta previa). For each subtype, the percentage of patients receiving blood products were 71% (PA), 28% (microscopic PA), 82% (increta), 82% (percreta), and 19% (no accreta). Among patients with PA or variants, 89% of patients with PA or variants underwent postpartum hysterectomy, compared to only 5% of patients with no or microscopic PA.Based on our experience and on the findings of our retrospective analysis, patients presenting with either antepartum radiological evidence or clinical suspicion of morbidly adherent placenta will benefit from a standardized protocol for clinical management, including transfusion medicine support. We found that massive hemorrhage is predictable when abnormal placentation is identified predelivery and that blood product support is substantial regardless of the degree of placental invasiveness. The protocol at our institution provides immediate access to sufficient volumes and types of blood products at delivery for patients at highest risk for life-threatening obstetric hemorrhage. Therefore, for patients with a diagnosis of morbidly adherent placenta scheduled for planned cesarean delivery with possible hysterectomy, a programmatic checklist that mobilizes a multidisciplinary team, including proactive transfusion medicine support, represents best practices.

    View details for DOI 10.1213/ANE.0000000000002050

    View details for PubMedID 28640786

  • National and International Guidelines for Patient Blood Management in Obstetrics: A Qualitative Review ANESTHESIA AND ANALGESIA Shaylor, R., Weiniger, C. F., Austin, N., Tzabazis, A., Shander, A., Goodnough, L. T., Butwick, A. J. 2017; 124 (1): 216-232


    In developed countries, rates of postpartum hemorrhage (PPH) requiring transfusion have been increasing. As a result, anesthesiologists are being increasingly called upon to assist with the management of patients with severe PPH. First responders, including anesthesiologists, may adopt Patient Blood Management (PBM) recommendations of national societies or other agencies. However, it is unclear whether national and international obstetric societies' PPH guidelines account for contemporary PBM practices. We performed a qualitative review of PBM recommendations published by the following national obstetric societies and international groups: the American College of Obstetricians and Gynecologists; The Royal College of Obstetricians and Gynecologists, United Kingdom; The Royal Australian and New Zealand College of Obstetricians and Gynecologists; The Society of Obstetricians and Gynecologists of Canada; an interdisciplinary group of experts from Austria, Germany, and Switzerland, an international multidisciplinary consensus group, and the French College of Gynaecologists and Obstetricians. We also reviewed a PPH bundle, published by The National Partnership for Maternal Safety. On the basis of our review, we identified important differences in national and international societies' recommendations for transfusion and PBM. In the light of PBM advances in the nonobstetric setting, obstetric societies should determine the applicability of these recommendations in the obstetric setting. Partnerships among medical, obstetric, and anesthetic societies may also help standardize transfusion and PBM guidelines in obstetrics.

    View details for DOI 10.1213/ANE.0000000000001473

    View details for Web of Science ID 000390613500025

  • The impact of postpartum hemoglobin levels on maternal quality of life after delivery: a prospective exploratory study. Annals of hematology Miller, C. M., Ramachandran, B., Akbar, K., Carvalho, B., Butwick, A. J. 2016; 95 (12): 2049-2055


    Postpartum anemia has been associated with postpartum morbidities, such as depression and poor cognition. However, it is unclear whether postpartum anemia is associated with reduced health-related quality of life. We performed a prospective study to examine the relations between postpartum Hb levels with postpartum health-related quality of life (HRQoL). We collected data from 60 women intending vaginal delivery and assessed HRQoL and maternal fatigue on admission and on the first postpartum day using the RAND 36-Item Short-Form Health Survey (SF-36) and the Multidimensional Fatigue Inventory (MFI), respectively. Maternal Hb levels were measured on admission and on the first postpartum day. We also assessed patients for postpartum depression using the Edinburgh Postpartum Depression Scale (EPDS). We performed unadjusted and multivariate linear regression (adjusting for maternal age, parity, mode of delivery, and race) to assess the associations between postdelivery Hb with each subscale of the SF-36 and MFI. The mean predelivery and postpartum Hb levels were 12.3 (1.2) and 10.8 (1.4) g/dl, respectively. In our unadjusted and adjusted regression analyses, we observed no statistically significant associations between postpartum Hb levels with any SF-36 or MFI subscale (P > 0.05). Based on the EPDS, only one patient was depressed; her postpartum Hb was 11.2 g/dl. Our findings suggest that postpartum Hb levels may not influence HRQoL or fatigue. However, our findings may only apply to women without predelivery anemia, severe blood loss or moderate-to-severe anemia after delivery. Future studies are needed to determine whether postpartum Hb influences HRQoL among women with moderate or severe postpartum anemia.

    View details for PubMedID 27623626

  • Evaluation of high-risk obstetric patients: a survey of US academic centers JOURNAL OF CLINICAL ANESTHESIA Butwick, A. J., Tiouririne, M. 2016; 33: 460-468


    Obstetric anesthesiologists commonly care for high-risk obstetric patients. However, it is unclear how obstetricians refer these patients for anesthetic evaluation and whether obstetric anesthesia clinics (OACs) are used. Our study aims were to determine the availability and characteristics of OACs at US academic obstetric centers and to evaluate how high-risk patients are referred for anesthetic evaluation.This is a survey study design.University of Virginia Center for Survey Research.A survey questionnaire was constructed and electronically mailed to obstetric anesthesia directors based at hospitals with accredited anesthesia residency programs.One hundred thirteen obstetric anesthesia directors were contacted. We asked questions about the presence and operational characteristics of OACs. These characteristics were compared between hospitals with high, medium, and low annual delivery volumes. We also inquired about how high-risk patients are referred for anesthetic evaluation. Frequencies were compared using Fisher test, with P< .05 considered as statistically significant.The survey response rate was 58% (n = 65). Overall, only 25 (38%) respondents indicated that their hospital operated an OAC. The proportion of hospitals with an OAC and OAC operational hours did not significantly vary according to hospital delivery volume. Among hospitals with an OAC, 24% respondents indicated that obstetricians always refer high-risk patients to the OAC. Nearly half of respondents (44%) indicated that high-risk patients usually or sometimes receive their first anesthetic evaluation during the delivery hospitalization.Our findings suggest that, among US academic centers, OACs are uncommon and the referral of high-risk patients for antenatal anesthetic evaluation is inconsistent. These findings suggest that more structured referral processes are needed to ensure that high-risk women receive anesthetic evaluation before labor or delivery.

    View details for DOI 10.1016/j.jclinane.2016.04.005

    View details for Web of Science ID 000382421800088

    View details for PubMedID 27555211

  • Knowledge of blood loss at delivery among postpartum patients PEERJ Farber, M. K., Miller, C. M., Ramachandran, B., Hegde, P., Akbar, K., Goodnough, L. T., Butwick, A. J. 2016; 4


    Postpartum hemorrhage (PPH) is a leading cause of obstetric morbidity. There is limited understanding of patients' knowledge about blood loss at delivery, PPH, and PPH-related morbidities, including transfusion and anemia.We surveyed 100 healthy postpartum patients who underwent vaginal or cesarean delivery about blood loss, and whether they received information about transfusion and peripartum hemoglobin (Hb) testing. Responses were compared between women undergoing vaginal delivery vs. cesarean delivery; P < 0.05 considered as statistically significant.In our cohort, 49 women underwent vaginal delivery and 51 women underwent cesarean delivery. Only 29 (29%) of women provided blood loss estimates for their delivery. Women who underwent cesarean delivery were more likely to receive clear information about transfusion therapy than those undergoing vaginal delivery (43.1% vs. 20.4% respectively; P = 0.04). Women who underwent vaginal delivery were more likely to receive results of postpartum Hb tests compared to those undergoing cesarean delivery (49% vs. 29.4%; P = 0.02).Our findings suggest that women are poorly informed about the magnitude of blood loss at delivery. Hematologic information given to patients varies according to mode of delivery. Further research is needed to better understand the clinical implications of patients' knowledge gaps about PPH, transfusion and postpartum anemia.

    View details for DOI 10.7717/peerj.2361

    View details for Web of Science ID 000383263900004

    View details for PubMedID 27635332

    View details for PubMedCentralID PMC5012285

  • Availability and Readability of Online Patient Education Materials Regarding Regional Anesthesia Techniques for Perioperative Pain Management. Pain medicine Kumar, G., Howard, S. K., Kou, A., Kim, T. E., Butwick, A. J., Mariano, E. R. 2016


    OBJECTIVE : Patient education materials (PEM) should be written at a sixth-grade reading level or lower. We evaluated the availability and readability of online PEM related to regional anesthesia and compared the readability and content of online PEM produced by fellowship and nonfellowship institutions. METHODS : With IRB exemption, we constructed a cohort of online regional anesthesia PEM by searching Websites from North American academic medical centers supporting a regional anesthesiology and acute pain medicine fellowships and used a standardized Internet search engine protocol to identify additional nonfellowship Websites with regional anesthesia PEM based on relevant keywords. Readability metrics were calculated from PEM using the TextStat 0.1.4 textual analysis package for Python 2.7 and compared between institutions with and without a fellowship program. The presence of specific descriptive PEM elements related to regional anesthesia was also compared between groups. RESULTS : PEM from 17 fellowship and 15 nonfellowship institutions were included in analyses. The mean (SD) Flesch-Kincaid Grade Level for PEM from the fellowship group was 13.8 (2.9) vs 10.8 (2.0) for the nonfellowship group (p = 0.002). We observed no other differences in readability metrics between fellowship and nonfellowship institutions. Fellowship-based PEM less commonly included descriptions of the following risks: local anesthetic systemic toxicity (p = 0.033) and injury due to an insensate extremity (p = 0.003). CONCLUSIONS : Available online PEM related to regional anesthesia are well above the recommended reading level. Further, fellowship-based PEM posted are at a higher reading level than PEM posted by nonfellowship institutions and are more likely to omit certain risk descriptions.

    View details for PubMedID 27485090

  • Maternal outcomes of term breech presentation delivery: impact of successful external cephalic version in a nationwide sample of delivery admissions in the United States BMC PREGNANCY AND CHILDBIRTH Weiniger, C. F., Lyell, D. J., Tsen, L. C., Butwick, A. J., Shachar, B., Callaghan, W. M., Creanga, A. A., Bateman, B. T. 2016; 16


    We aimed to define the frequency and predictors of successful external cephalic version in a nationally-representative cohort of women with breech presentations and to compare maternal outcomes associated with successful external cephalic version versus persistent breech presentation.Using the Nationwide Inpatient Sample, a United States healthcare utilization database, we identified delivery admissions between 1998 and 2011 for women who had successful external cephalic version or persistent breech presentation (including unsuccessful or no external cephalic version attempt) at term. Multivariable logistic regression identified patient and hospital-level factors associated with successful external cephalic version. Maternal outcomes were compared between women who had successful external cephalic version versus persistent breech.Our study cohort comprised 1,079,576 delivery admissions with breech presentation; 56,409 (5.2 %) women underwent successful external cephalic version and 1,023,167 (94.8 %) women had persistent breech presentation at the time of delivery. The rate of cesarean delivery was lower among women who had successful external cephalic version compared to those with persistent breech (20.2 % vs. 94.9 %; p < 0.001). Compared to women with persistent breech at the time of delivery, women with successful external cephalic version were also less likely to experience several measures of significant maternal morbidity including endometritis (adjusted Odds Ratio (aOR) = 0.36, 95 % Confidence Interval (CI) 0.24-0.52), sepsis (aOR = 0.35, 95 % CI 0.24-0.51) and length of stay > 7 days (aOR = 0.53, 95 % CI 0.40-0.70), but had a higher risk of chorioamnionitis (aOR = 1.83, 95 % CI 1.54-2.17).Overall a low proportion of women with breech presentation undergo successful external cephalic version, and it is associated with significant reduction in the frequency of cesarean delivery and a number of measures of maternal morbidity. Increased external cephalic version use may be an important approach to mitigate the high rate of cesarean delivery observed in the United States.

    View details for DOI 10.1186/s12884-016-0941-9

    View details for Web of Science ID 000379605300001

    View details for PubMedID 27392035

  • Does Time of Delivery Influence the Risk of Neonatal Morbidity? American journal of perinatology Brookfield, K. F., O'Malley, K., El-Sayed, Y. Y., Blumenfeld, Y. J., Butwick, A. J. 2016; 33 (5): 502-509


    Objective To examine whether time of delivery influences the risk of neonatal morbidity among women with singleton pregnancies. Study Design Secondary analysis of data from the Maternal Fetal Medicine Units Network Factor V Leiden Mutation study. We categorized time of delivery as day (07:00-16:59), evening (17:00-23:59), and overnight (midnight-06:59). Severe neonatal morbidity was defined by at least one of the following: respiratory distress syndrome, transient tachypnea of the newborn, sepsis, seizures, neonatal intensive care admission, or a 5-minute APGAR ≤3. We calculated frequencies of severe neonatal morbidity by time of delivery. Multivariate analysis was performed to determine whether time of delivery was independently associated with severe neonatal morbidity. Results Among 4,087 women, 1,917 (46.9%) delivered during the day, 1,140 (27.9%) delivered in the evening, and 1,030 (25.2%) delivered overnight. We observed no significant differences in the rates of neonatal morbidity between delivery time periods (day: 12.3%; evening: 12.8%; overnight: 12.6%; p = 0.9). No significant association was observed between time of delivery and neonatal morbidity after adjustment for maternal, obstetric, and peripartum factors. Conclusion Our findings suggest that time of delivery is not associated with severe neonatal morbidity.

    View details for DOI 10.1055/s-0035-1567891

    View details for PubMedID 26595143

  • Israeli survey of anesthesia practice related to placenta previa and accreta. Acta anaesthesiologica Scandinavica Ioscovich, A., Shatalin, D., Butwick, A. J., Ginosar, Y., Orbach-Zinger, S., Weiniger, C. F. 2016; 60 (4): 457-464


    Anesthesia practices for placenta previa (PP) and accreta (PA) impact hemorrhage management and other supportive strategies. We conducted a survey to assess reported management of PP and PA in all Israeli labor and delivery units.After Institutional Review Board waiver, we surveyed all 26 Israeli hospitals with a labor and delivery unit by directly contacting the representatives of obstetric anesthesiology services in every department (unit director or department chair). Each director surveyed provided information about the anesthetic and transfusion management in their labor and delivery units for three types of abnormal placentation based on antenatal placental imaging: PP, low suspicion for PA, and high suspicion for PA. The primary outcome was use of neuraxial or general anesthesia for PP and PA Cesarean delivery. Univariate statistics were used for survey responses using counts and percentages.The response rate was 100%. Spinal anesthesia is the preferred anesthetic mode for PP cases, used in 17/26 (65.4%) of labor and delivery units. By comparison, most representatives reported that they perform general anesthesia for patients with PA: 18/26 (69.2%) for all low suspicion cases of PA and 25/26 (96.2%) for all high suspicion cases of PA. Although a massive transfusion protocol was available in the majority of hospitals (84.6%), the availability of thromboelastography and cell salvage was much lower (53.8% and 19.2% hospitals respectively).In our survey, representatives of anesthesia labor and delivery services in Israel are almost exclusively using general anesthesia for women with high suspicion for PA; however, almost two-thirds use spinal anesthesia for PP without suspicion of PA. Among representatives, we found wide variations in anesthesia practice patterns with regard to anesthesia mode, multidisciplinary management, and hemorrhage anticipation strategies.

    View details for DOI 10.1111/aas.12656

    View details for PubMedID 26597396

  • Labor outcome at extremely advanced maternal age. American journal of obstetrics and gynecology Osmundson, S. S., Gould, J. B., Butwick, A. J., Yeaton-Massey, A., El-Sayed, Y. Y. 2016; 214 (3): 362 e1-7


    Women of advanced maternal age (AMA) are at increased risk for cesarean delivery compared to non-AMA women. However, it is unclear whether how this association is altered by parity and the presence or absence of a trial of labor.We sought to examine modes of delivery and maternal outcomes among AMA women stratified by parity and the presence or absence of a trial of labor.This is a retrospective cohort study of all women delivering singletons births at ≥20 weeks' gestation in the state of California from 2007 through 2011. Data were extracted from maternal discharge data linked to infant birth certificate records. We compared non-AMA women (age 20-34 years, reference group) to AMA women who were classified as follows: age 35-39, 40-44, 45-49, and ≥50 years). The primary outcome was route of delivery (cesarean vs vaginal) stratified by parity and whether a trial of labor occurred (prelabor vs intrapartum cesarean delivery). The association between a trial of labor and perinatal morbidity was also studied.There were 1,346,889 women who met inclusion criteria, which included 181 (0.01%) women who were age ≥50 years at the time of delivery. Overall, 34.7% underwent a cesarean delivery and this risk differed significantly by age group (30.5%, 20-34 years; 40.5%, 35-39 years; 47.3%, 40-44 years; 55.6%, 45-49 years; 62.4%, >50 years). Nulliparous women age ≥50 years were significantly less likely to undergo a trial of labor compared to the reference group (relative risk [RR], 0.44; 95% confidence interval [CI], 0.32-0.62). Furthermore, nulliparous women age ≥50 years were significantly more likely to experience an intrapartum cesarean delivery (RR, 2.61; 95% CI, 1.31-5.20), however the majority (74%) who underwent a trial of labor experienced a vaginal delivery. Compared to the reference group, women age ≥50 years were 5 times more likely to experience severe maternal morbidity (1.7% vs 0.3%; RR, 5.08; 95% CI, 1.65-15.61) and their infants 3 times more likely to require neonatal intensive care unit admission (14.9% vs 5.2%; RR, 3.1; 95% CI, 2.2-4.4), however these outcomes were not associated significantly with having undergone a trial of labor, a cesarean delivery following labor, or a prelabor cesarean delivery. Similar trends were observed among multiparous women.Compared to non-AMA women, women age ≥50 years with a singleton pregnancy experience significantly higher rates of cesarean delivery. However the majority of those who undergo a trial of labor will have a vaginal delivery. Neither a trial of labor nor a prelabor cesarean delivery is significantly associated with maternal or neonatal morbidity. These data support either approach in women of extremely AMA.

    View details for DOI 10.1016/j.ajog.2015.09.103

    View details for PubMedID 26454124

  • Checklists and multidisciplinary team performance during simulated obstetric hemorrhage. International journal of obstetric anesthesia Hilton, G., Daniels, K., Goldhaber-Fiebert, S. N., Lipman, S., Carvalho, B., Butwick, A. 2016; 25: 9-16


    Checklists can optimize team performance during medical crises. However, there has been limited examination of checklist use during obstetric crises. In this simulation study we exposed multidisciplinary teams to checklist training to evaluate checklist use and team performance during a severe postpartum hemorrhage.Fourteen multidisciplinary teams participated in a postpartum hemorrhage simulation occurring after vaginal delivery. Before participating, each team received checklist training. The primary study outcome was whether each team used the checklist during the simulation. Secondary outcomes were the times taken to activate our institution-specific massive transfusion protocol and commence red blood cell transfusion, and whether a designated checklist reader was used.The majority of teams (12/14 (86%)) used the checklist. Red blood cell transfusion was administered by all teams. The median [IQR] times taken to activate the massive transfusion protocol and transfuse red blood cells were 5min 14s [3:23-6:43] and 14min 40s [12:56-17:28], respectively. A designated checklist reader was used by 7/12 (58%) teams that used the checklist. Among teams that used a checklist with versus without a designated reader, we observed no differences in the times to activate the massive transfusion protocol or to commence red blood cell transfusion (P>0.05).Although checklist training was effective in promoting checklist use, multidisciplinary teams varied in their scope of checklist use during a postpartum hemorrhage simulation. Future studies are required to determine whether structured checklist training can result in more standardized checklist use during a postpartum hemorrhage.

    View details for DOI 10.1016/j.ijoa.2015.08.011

    View details for PubMedID 26421705

  • Racial and Ethnic Disparities in Mode of Anesthesia for Cesarean Delivery ANESTHESIA AND ANALGESIA Butwick, A. J., Blumenfeld, Y. J., Brookfield, K. F., Nelson, L. M., Weiniger, C. F. 2016; 122 (2): 472-479


    Racial and ethnic disparities have been identified in the provision of neuraxial labor analgesia. These disparities may exist in other key aspects of obstetric anesthesia care. We sought to determine whether racial/ethnic disparities exist in mode of anesthesia for cesarean delivery (CD).Women who underwent CD between 1999 and 2002 at 19 different obstetric centers in the United States were identified from the Maternal-Fetal Medicine Units Network Cesarean Registry. Race/ethnicity was categorized as: Caucasian, African American, Hispanic, and Non-Hispanic Others (NHOs). Mode of anesthesia was classified as neuraxial anesthesia (spinal, epidural, or combined spinal-epidural anesthesia) or general anesthesia. To account for obstetric and non-obstetric covariates that may have influenced mode of anesthesia, multiple logistic regression analyses were performed by using sequential sets of covariates.The study cohort comprised 50,974 women who underwent CD. Rates of general anesthesia among racial/ethnic groups were as follows: 5.2% for Caucasians, 11.3% for African Americans, 5.8% for Hispanics, and 6.6% for NHOs. After adjustment for obstetric and non-obstetric covariates, African Americans had the highest odds of receiving general anesthesia compared with Caucasians (adjusted odds ratio [aOR] = 1.7; 95% confidence interval [CI], 1.5-1.8; P < 0.001). The odds of receiving general anesthesia were also higher among Hispanics (aOR = 1.1; 95% CI, 1.0-1.3; P = 0.02) and NHOs (aOR = 1.2; 95% CI, 1.0-1.4; P = 0.03) compared with Caucasians, respectively. In our sensitivity analysis, we reconstructed the models after excluding women who underwent neuraxial anesthesia before general anesthesia. The adjusted odds of receiving general anesthesia were similar to those in the main analysis: African Americans (aOR = 1.7; 95% CI, 1.5-1.9; P < 0.001); Hispanics (aOR = 1.2; 95% CI, 1.1-1.4; P = 0.006); and NHOs (aOR = 1.2; 95% CI, 1.0-1.5; P = 0.05).Based on data from the Cesarean Registry, African American women had the highest odds of undergoing general anesthesia for CD compared with Caucasian women. It is uncertain whether this disparity exists in current obstetric practice.

    View details for DOI 10.1213/ANE.0000000000000679

    View details for Web of Science ID 000368646500001

  • Can extra carbs improve perinatal outcomes? BJOG : an international journal of obstetrics and gynaecology Sutton, C., Butwick, A. J. 2016; 123 (4): 518

    View details for DOI 10.1111/1471-0528.13814

    View details for PubMedID 26914894

  • In Response. Anesthesia and analgesia Bateman, B. T., Butwick, A. J., Huybrechts, K. F. 2015; 121 (5): 1397-1398

    View details for DOI 10.1213/ANE.0000000000000847

    View details for PubMedID 26484466

  • Morbidity associated with cesarean delivery in the United States: is placenta accreta an increasingly important contributor? AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Creanga, A. A., Bateman, B. T., Butwick, A. J., Raleigh, L., Maeda, A., Kuklina, E., Callaghan, W. M. 2015; 213 (3)


    To examine cesarean morbidity and its predictors in the United States.We used 2000-2011 Nationwide Inpatient Sample data to identify cesarean deliveries and records with 12 potential cesarean complications, including placenta accreta. We estimated cesarean morbidity rates and rate changes during 2000-2011, and fitted Poisson regression models to assess the relative incidence of morbidity among repeat versus primary cesareans and explore its predictors.During 2000-2011, 76 in 1,000 cesareans (97 in 1,000 primary and 48 in 1,000 repeat cesareans) were accompanied by ≥1 of 12 complications. The unadjusted composite cesarean morbidity rate increased by 3.6% only among women with a primary cesarean (p<0.001), while the unadjusted rate of placenta accreta increased by 30.8% only among women with a repeat cesarean (p=0.025). The adjusted rate of overall composite cesarean morbidity decreased by 1% annually during 2000-2011 (p<0.001). Compared to women with a primary cesarean, those who underwent a repeat cesarean were half as likely (incidence rate ratio=0.50; 95%CI 0.49-0.50) to develop a complication, but 2.13 (95%CI 1.98-2.29) times more likely to have a placenta accreta diagnosis. Both cesarean morbidity and placenta accreta were positively associated with: age >30 years; non-Hispanic black race-ethnicity; presence of a chronic medical condition; and delivery in urban, teaching, or larger hospitals.Overall, cesarean morbidity declined modestly during 2000-2011, but placenta accreta became an increasingly important contributor to repeat cesarean morbidity. Clinicians should maintain a high index of suspicion for abnormal placentation and make adequate preparations for patients who need cesarean deliveries.

    View details for DOI 10.1016/j.ajog.2015.05.002

    View details for Web of Science ID 000360551700027

    View details for PubMedID 25957019

  • Mode of anaesthesia for preterm Caesarean delivery: secondary analysis from the Maternal-Fetal Medicine Units Network Caesarean Registry†‡. British journal of anaesthesia Butwick, A. J., El-Sayed, Y. Y., Blumenfeld, Y. J., Osmundson, S. S., Weiniger, C. F. 2015; 115 (2): 267-274


    Preterm delivery is often performed by Caesarean section. We investigated modes of anaesthesia and risk factors for general anaesthesia among women undergoing preterm Caesarean delivery.Women undergoing Caesarean delivery between 24(+0) and 36(+6) weeks' gestation were identified from a multicentre US registry. The mode of anaesthesia was classified as neuraxial anaesthesia (spinal, epidural, or combined spinal and epidural) or general anaesthesia. Logistic regression was used to identify patient characteristic, obstetric, and peripartum risk factors associated with general anaesthesia.Within the study cohort, 11 539 women had preterm Caesarean delivery; 9510 (82.4%) underwent neuraxial anaesthesia and 2029 (17.6%) general anaesthesia. In our multivariate model, African-American race [adjusted odds ratio (aOR)=1.9; 95% confidence interval (CI)=1.7-2.2], Hispanic ethnicity (aOR=1.5; 95% CI=1.2-1.8), other race (aOR=1.4; 95% CI=1.1-1.9), and haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome or eclampsia (aOR=2.8; 95% CI=2.2-3.5) were independently associated with receiving general anaesthesia for preterm Caesarean delivery. Women with an emergency Caesarean delivery indication had the highest odds for general anaesthesia (aOR=3.5; 95% CI=3.1-3.9). For every 1 week decrease in gestational age at delivery, the adjusted odds of general anaesthesia increased by 13%.In our study cohort, nearly one in five women received general anaesthesia for preterm Caesarean delivery. Although potential confounding by unmeasured factors cannot be excluded, our findings suggest that early gestational age at delivery, emergent Caesarean delivery indications, hypertensive disease, and non-Caucasian race or ethnicity are associated with general anaesthesia for preterm Caesarean delivery.

    View details for DOI 10.1093/bja/aev108

    View details for PubMedID 25956901

  • Risk Factors for Prolonged Postpartum Length of Stay Following Cesarean Delivery AMERICAN JOURNAL OF PERINATOLOGY Blumenfeld, Y. J., El-Sayed, Y. Y., Lyell, D. J., Nelson, L. M., Butwick, A. J. 2015; 32 (9): 825-832


    Objective This study aims to identify risk factors for prolonged postpartum length of stays (LOS) after cesarean delivery (CD). Study Design Patients undergoing CD were sourced from a multicenter registry of 19 academic centers between 1999 and 2002 (n = 57,067). Prolonged postpartum LOS was defined as a hospitalization duration ≥ 90th centile. Maternal, antepartum, perioperative, and neonatal variables were compared between women with and without prolonged postpartum LOS. Results The 90th centile for postpartum LOS was 4 days, with 14,954 women experiencing prolonged postpartum LOS. Women with perioperative complications had the highest independent risk for a prolonged postpartum LOS: ileus (adjusted odds ratio [aOR] = 12.28; 95% confidence interval CI = 8.98-16.8); endometritis (aOR = 10.45; 95% CI = 9.51-11.5), and wound complications (aOR = 5.49; 95% CI = 4.54-6.63). Several antepartum, perioperative, and neonatal variables were associated with a prolonged postpartum LOS. Conclusion Perioperative complications had the highest risk for prolonged LOS after CD. Strategies to reduce perioperative complications are needed to decrease the health care burden of prolonged post-CD LOS.

    View details for DOI 10.1055/s-0034-1543953

    View details for Web of Science ID 000358571000004

  • Transfusion and coagulation management in major obstetric hemorrhage CURRENT OPINION IN ANESTHESIOLOGY Butwick, A. J., Goodnough, L. T. 2015; 28 (3): 275-284


    Major obstetric hemorrhage is a leading cause of maternal morbidity and mortality. We will review transfusion strategies and the value of monitoring the maternal coagulation profile during severe obstetric hemorrhage.Epidemiologic studies indicate that rates of severe postpartum hemorrhage (PPH) in well resourced countries are increasing. Despite these increases, rates of transfusion in obstetrics are low (0.9-2.3%), and investigators have questioned whether a predelivery 'type and screen' is cost-effective for all obstetric patients. Instead, blood ordering protocols specific to obstetric patients can reduce unnecessary antibody testing. When severe PPH occurs, a massive transfusion protocol has attracted interest as a key therapeutic resource by ensuring sustained availability of blood products to the labor and delivery unit. During early postpartum bleeding, recent studies have shown that hypofibrinogenemia is an important predictor for the later development of severe PPH. Point-of-care technologies, such as thromboelastography and rotational thromboelastometry, can identify decreased fibrin clot quality during PPH, which correlate with low fibrinogen levels.A massive transfusion protocol provides a key resource in the management of severe PPH. However, future studies are needed to assess whether formula-driven vs. goal-directed transfusion therapy improves maternal outcomes in women with severe PPH.

    View details for DOI 10.1097/ACO.0000000000000180

    View details for Web of Science ID 000353844000008

    View details for PubMedID 25812005

  • Second-line uterotonics and the risk of hemorrhage-related morbidity. American journal of obstetrics and gynecology Butwick, A. J., Carvalho, B., Blumenfeld, Y. J., El-Sayed, Y. Y., Nelson, L. M., Bateman, B. T. 2015; 212 (5): 642 e1-7


    Uterine atony is a leading cause of postpartum hemorrhage (PPH). Although most cases of PPH respond to first line therapy with uterine massage and oxytocin administration, second line uterotonics including methylergonovine and carboprost are integral for the management of refractory uterine atony. Despite their ubiquitous use, it is uncertain whether the risk of hemorrhage-related morbidity differs in women exposed to methylergonovine or carboprost at Cesarean delivery (CD).We performed a secondary analysis using the Maternal-Fetal Medicine Units Network Cesarean Registry. We identified women who underwent CD and received either methylergonovine or carboprost for refractory uterine atony. The primary outcome was hemorrhage-related morbidity defined as intraoperative or postoperative red blood cells (RBC) transfusion or the need for additional surgical interventions including uterine artery ligation, hypogastric artery ligation, or peripartum hysterectomy for atony. We compared the risk of hemorrhage-related morbidity in those exposed to methylergonovine vs. carboprost. Propensity-score matching was used to account for potential confounders.The study cohort comprised 1,335 women; 870 (65.2%) women received methylergonovine and 465 (34.8%) women received carboprost. After accounting for potential confounders, the risk of hemorrhage-related morbidity was higher in the carboprost group than the methylergonovine group (RR = 1.7; 95% CI = 1.2 - 2.6).In this propensity-score matched analysis, methylergonovine was associated with reduced risk of hemorrhage-related morbidity during CD compared to carboprost. Based on these results, methylergonovine may be a more effective second line uterotonic.

    View details for DOI 10.1016/j.ajog.2015.01.008

    View details for PubMedID 25582104

  • Antenatal Corticosteroids for Preterm Premature Rupture of Membranes: Single or Repeat Course? AMERICAN JOURNAL OF PERINATOLOGY Brookfield, K. F., El-Sayed, Y. Y., Chao, L., Berger, V., Naqvi, M., Butwick, A. J. 2015; 32 (6): 537-543

    View details for DOI 10.1055/s-0034-1396690

    View details for Web of Science ID 000354342400005

    View details for PubMedID 25545441

  • The impact of advanced maternal age on peripartum thromboelastographic coagulation profiles: a prospective observational exploratory study CANADIAN JOURNAL OF ANESTHESIA-JOURNAL CANADIEN D ANESTHESIE Butwick, A., Gutierrez, M. C., Hilton, G. 2015; 62 (5): 504-512


    Advanced maternal age (AMA) is a known risk factor for pregnancy-related venous thromboembolism. However, it is unclear if underlying differences exist in the maternal coagulation profiles of AMA vs non-AMA women. The aim of this prospective observational study was to compare peripartum thromboelastography parameters of AMA and non-AMA women undergoing elective Cesarean delivery (CD).We compared the peripartum thromboelastographic profiles of healthy AMA women (age > 35 yr) and non-AMA women (age ≤ 35 yr) undergoing elective CD under neuraxial anesthesia. Blood samples were drawn prior to CD and at 24 hr and 72 hr post-CD. At each time point, we assessed thromboelastographic and other standard laboratory coagulation indices. We used a linear mixed-effects regression model (SAS(®) PROC MIXED) to assess between-group differences for individual thromboelastographic and laboratory coagulation parameters.The median [interquartile range] ages of women were 38 [37-41] yr and 29 [25-34] yr in the AMA and non-AMA groups, respectively (P < 0.001). We observed no statistically significant effect of study group on any thromboelastographic or laboratory coagulation parameters. No statistically significant correlations were found between any thromboelastographic parameter and maternal age. Peripartum thromboelastography and coagulation profiles of healthy AMA and healthy non-AMA women up to 72 hr post-CD were also similar.These data suggest that maternal thromboelastographic profiles of healthy AMA and non-AMA women undergoing elective CD are similar. The study was registered at (identifier: NCT01416454).

    View details for DOI 10.1007/s12630-014-0300-0

    View details for Web of Science ID 000352615100009

    View details for PubMedID 25549988

  • Second-line uterotonics and the risk of hemorrhage-related morbidity AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Butwick, A. J., Carvalho, B., Blumenfeld, Y. J., El-Sayed, Y. Y., Nelson, L. M., Bateman, B. T. 2015; 212 (5)

    View details for DOI 10.1016/j.ajog.2015.01.008

    View details for Web of Science ID 000353598500025

    View details for PubMedID 25582104

  • In response. Anesthesia and analgesia Ducloy-Bouthors, A., Vallet, B., Susen, S., Wong, C. A., Butwick, A., Lockhart, E. 2015; 120 (4): 956-957

    View details for DOI 10.1213/ANE.0000000000000621

    View details for PubMedID 25790218

  • Patterns of Second-Line Uterotonic Use in a Large Sample of Hospitalizations for Childbirth in the United States: 2007-2011 ANESTHESIA AND ANALGESIA Bateman, B. T., Tsen, L. C., Liu, J., Butwick, A. J., Huybrechts, K. F. 2014; 119 (6): 1344-1349
  • Elective ceasarean section at 38 weeks versus 39 weeks: neonatal and maternal outcomes in a randomised controlled trial reply BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY Cho, Y., Carvalho, B., Butwick, A., Blumenfeld, Y., Riley, E. 2014; 121 (13): 1748-1749
  • Elective ceasarean section at 38 weeks versus 39 weeks: neonatal and maternal outcomes in a randomised controlled trial. BJOG : an international journal of obstetrics and gynaecology Cho, Y., Carvalho, B., Butwick, A., Blumenfeld, Y., Riley, E. 2014; 121 (13): 1748-?

    View details for DOI 10.1111/1471-0528.13079

    View details for PubMedID 25413764

  • Medical Advances in the Treatment of Postpartum Hemorrhage ANESTHESIA AND ANALGESIA Ducloy-Bouthors, A., Susen, S., Wong, C. A., Butwick, A., Vallet, B., Lockhart, E. 2014; 119 (5): 1140-1147


    Postpartum hemorrhage (PPH) is a leading cause of maternal mortality worldwide. Recent advances in the management of severe bleeding for trauma patients may provide insight into PPH management, but must be applied with caution considering the significant differences between trauma and obstetric patients. In this review, we summarized evidence for current management strategies for patients with major obstetric hemorrhage, including (1) rapid laboratory assessment of coagulopathy, (2) early transfusion of plasma and high plasma-to-red blood cell transfusion ratios in massive PPH, and (3) use of tranexamic acid and fibrinogen concentrates in the setting of PPH complicated by coagulopathy.

    View details for DOI 10.1213/ANE.0000000000000450

    View details for Web of Science ID 000343633500022

    View details for PubMedID 25329026

  • Risk factors for obstetric morbidity in patients with uterine atony undergoing Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B., El-Sayed, Y. Y. 2014; 113 (4): 661-668

    View details for DOI 10.1093/bja/aeu150

    View details for Web of Science ID 000343087400019

  • Anticoagulant prescribing practices and anesthetic interventions among anticoagulated pregnant patients: a retrospective study. International journal of obstetric anesthesia Butwick, A., Hass, C., Wong, J., Lyell, D., El-Sayed, Y. 2014; 23 (3): 238-245


    The peripartum management of anticoagulated patients poses important challenges for obstetric anesthesiologists, especially when deciding to perform neuraxial block. However, there is limited evidence evaluating anticoagulant prescribing practices and neuraxial block utilization in this setting. Our objective was to examine peripartum anticoagulant prescribing and anesthetic practices in a cohort of anticoagulated patients receiving subcutaneous enoxaparin, and subcutaneous or intravenous unfractionated heparin.We performed a retrospective study of anticoagulant prescribing patterns and anesthetic interventions among patients receiving enoxaparin and/or unfractionated heparin who delivered at a USA obstetric center over a seven-year period.We identified 101 patients who received enoxaparin and/or unfractionated heparin before delivery. Thirty-nine (38.6%) patients received enoxaparin only, 41 (40.6%) patients received enoxaparin bridged to subcutaneous unfractionated heparin, 11 (10.9%) patients received enoxaparin and were converted to intravenous unfractionated heparin and 10 (9.9%) patients received only subcutaneous unfractionated heparin. The overall rate of neuraxial block utilization was 80.2%. The median [IQR] time-period between the last dose of enoxaparin and neuraxial block was significantly shorter for patients who received only enoxaparin vs. enoxaparin with subcutaneous unfractionated heparin (54h [12-192h] (n=26) vs. 216h [39-504h] (n=23), P=0.04). Among patients who received only subcutaneous unfractionated heparin, the time period between unfractionated heparin and neuraxial block was 24h [19-51h].In this study, the neuraxial block rate was high among patients receiving enoxaparin and/or subcutaneous unfractionated heparin with patients undergoing relatively long periods off anticoagulation. Careful multidisciplinary planning is recommended for the peripartum management of anticoagulated pregnant patients.

    View details for DOI 10.1016/j.ijoa.2014.03.007

    View details for PubMedID 24910353

  • Perioperative and transfusion outcomes in women undergoing cesarean hysterectomy for abnormal placentation. Transfusion Brookfield, K. F., Goodnough, L. T., Lyell, D. J., Butwick, A. J. 2014; 54 (6): 1530-1536


    Women with placenta increta (PI) and placenta percreta (PP) are at high risk of obstetric hemorrhage; however, the severity of hemorrhage and perioperative morbidity may differ according to the degree of placental invasion. We sought to compare blood component usage and perioperative morbidity between women with PI versus PP undergoing cesarean hysterectomy (CH).We identified 77 women who underwent CH for PI or PP from the NICHD MFMU Network Cesarean Registry, which sourced data from 19 centers from 1999 to 2002. We examined demographic, obstetric, and surgical data and rates of transfusion and perioperative morbidity. We performed statistical tests for between-group analyses; p values less than 0.05 were significant.Rates of intraoperative or postoperative red blood cell (RBC) transfusion were similar between groups (PI 84% vs. PP 88%; p = 0.7). We observed no between-group differences in rates of fresh-frozen plasma (FFP) transfusion (intraoperative FFP-PI 30% vs. PP 41%; p = 0.3; postoperative FFP-PI 28% vs. PP 18%; p = 0.4) or platelet (PLT) transfusion (intraoperative PLTs-PI 14% vs. PP 29%; p = 0.2; postoperative PLTs-PI 9% vs. PP 9%; p = 1.0). Among the morbidities, a higher proportion of PP women underwent cystotomy (PI 14% vs. PP 38%; p = 0.02) and postoperative mechanical ventilation (PI 14% vs. PP 35%; p = 0.03).Rates of intraoperative RBC, FFP, and PLT transfusion are similar for PI and PP women, and perioperative outcomes are worse for PP women. We suggest the same mobilization transfusion medicine support for both groups, including blood ordering (type and cross-match for CH) and availability of emergency blood protocols including fibrinogen-containing preparations.

    View details for DOI 10.1111/trf.12483

    View details for PubMedID 24188691

  • Preferred spoken language mediates differences in neuraxial labor analgesia utilization among racial and ethnic groups. International journal of obstetric anesthesia Caballero, J. A., Butwick, A. J., Carvalho, B., Riley, E. T. 2014; 23 (2): 161-167


    The aims of this study were to assess racial/ethnic disparities for neuraxial labor analgesia utilization and to determine if preferred spoken language mediates the association between race/ethnicity and neuraxial labor analgesia utilization.We performed a retrospective cohort study of 3129 obstetric patients who underwent vaginal delivery at a tertiary care obstetric center. Bivariate analyses and multivariate logistic regression models were used to assess the relationships between race/ethnicity, preferred spoken language and neuraxial labor analgesia.Hispanic ethnicity (adjusted OR 0.77, 95% CI 0.61-0.98) and multiparity (adjusted OR 0.59, 95% CI 0.51-0.69) were independently associated with a reduced likelihood of neuraxial labor analgesia utilization. When preferred spoken language was controlled for, the effect of Hispanic ethnicity was no longer significant (adjusted OR 0.84, 95% CI 0.66-1.08) and only non-English preferred spoken language (adjusted OR 0.82, 95% CI 0.67-0.99) and multiparity (adjusted OR 0.59, 95% CI 0.51-0.69) were associated with a reduced likelihood of neuraxial labor analgesia utilization.This study provides evidence that preferred spoken language mediates the relationship between Hispanic ethnicity and neuraxial labor analgesia utilization.

    View details for DOI 10.1016/j.ijoa.2013.09.001

    View details for PubMedID 24703871

  • Preventing spinal hypotension during Caesarean delivery: what is the latest? British journal of anaesthesia Butwick, A. J., Columb, M. O., Carvalho, B. 2014

    View details for DOI 10.1093/bja/aeu267

    View details for PubMedID 25080429

  • Obstetric Anesthesia Clinics (Commentary Article) Society of Obstetric Anesthesia and Perinatology - Summer Newsletter Butwick, A., Tiouririne, M. 2014
  • Platelet Counts and Coagulation Tests Prior to Neuraxial Anesthesia in Patients With Preeclampsia A Retrospective Analysis CLINICAL AND APPLIED THROMBOSIS-HEMOSTASIS Sultan, P., Butwick, A. 2013; 19 (5): 529-534


    This retrospective, descriptive study aimed to assess hematologic testing practices in 100 patients with preeclampsia undergoing neuraxial blockade (NB). Prior to NB, platelet (PLT) count was performed in 61 (98%) of 62 women in labor and in 37 (97%) of 38 women undergoing cesarean delivery (CD). No patients had a pre-NB PLT count <70 × 10(9)/L. Pre-NB tests for prothrombin time (PT) and activated partial thromboplastin time (APTT) were less common and varied among laboring patients (15 [24%] of 62) and patients prior to CD (18 [47%] of 38). Prior to NB, PT and APTT values were within normal limits in all patients. The time intervals between laboratory testing and NB ranged from <2 to >12 hours. The lack of consistency in pre-NB coagulation testing and the variable time intervals between laboratory tests and NB may be due to a lack of consensus among anesthesiologists for determining "safe" hemostatic conditions for NB placement in patients with preeclampsia.

    View details for DOI 10.1177/1076029612441860

    View details for Web of Science ID 000324472400010

    View details for PubMedID 22531481

  • Anesthetic management of a parturient with VACTERL association undergoing Cesarean delivery. Canadian journal of anaesthesia = Journal canadien d'anesthésie Hilton, G., Mihm, F., Butwick, A. 2013; 60 (6): 570-576


    PURPOSE: We present the anesthetic management of a parturient with VACTERL association undergoing combined regional and general anesthesia for Cesarean delivery. Defined as a syndrome, VACTERL association comprises at least three of the following abnormalities: vertebral, anal atresia, cardiac, tracheoesophageal, renal, and limb. CLINICAL FEATURES: The patient's anatomic abnormalities and comorbidities comprised severe cervicothoracic scoliosis, kyphoscoliosis, congenitally fused ribs, and severe restrictive lung disease. She had a Mallampati class 3 airway, a right laterally flexed neck, and reduced mandibular protrusion. We performed a lumbar spine ultrasound for epidural placement which was used to provide peri- and postoperative analgesia. Due to the anticipated difficult tracheal intubation, the patient underwent an awake fibreoptic intubation and subsequently received general anesthesia. The patient's trachea was extubated on the first postoperative day, and she received adequate post-Cesarean epidural analgesia. CONCLUSION: This case highlights the challenges that anesthesiologists face when managing parturients at extremely high risk for perioperative anesthetic morbidity due to the presence of severe pre-existing disease, anticipated difficult airway, and major spinal abnormalities complicating neuraxial anesthesia. We used a combined general and epidural anesthetic approach to control ventilation, provide effective postoperative analgesia, and reduce the risk of anesthetic-related perioperative morbidity. An individualized approach should be considered for the anesthetic management of high-risk pregnant patients with complex and multiple medical and surgical morbidities undergoing labour and delivery.

    View details for DOI 10.1007/s12630-013-9919-5

    View details for PubMedID 23519725

  • Methodological queries about point-of-care haemoglobin data ANAESTHESIA Butwick, A. 2013; 68 (5): 540-541

    View details for DOI 10.1111/anae.12187

    View details for Web of Science ID 000317520200027

    View details for PubMedID 23573859

  • Postpartum hemorrhage and low fibrinogen levels: the past, present and future. International journal of obstetric anesthesia Butwick, A. J. 2013; 22 (2): 87-91

    View details for DOI 10.1016/j.ijoa.2013.01.002

    View details for PubMedID 23473552

  • General anesthesia at cesarean delivery portends worse maternal and neonatal outcomes 33rd Annual Pregnancy Meeting of the Society-for-Maternal-Fetal-Medicine (SMFM) Brookfield, K., Osmundson, S., Naqvi, M., Butwick, A., Lyelll, D. MOSBY-ELSEVIER. 2013: S283–S283
  • What's New in Obstetric Anesthesia in 2011? Reducing Maternal Adverse Outcomes and Improving Obstetric Anesthesia Quality of Care ANESTHESIA AND ANALGESIA Butwick, A. 2012; 115 (5): 1137-1145


    This article accompanied the "What's New in Obstetric Anesthesia?" lecture presented at the Society for Obstetric Anesthesia and Perinatology Annual Meeting in May 2012. The invited lecturer reviewed the obstetric, obstetric anesthesiology, perinatology, and key medical literature published in 2011. This review identifies key topics and themes from the 2011 literature relevant to the science and clinical practice of obstetric anesthesiology and the interdisciplinary care of obstetric patients. Specific topics include health care policy issues that affect pregnant women, updated information on maternal mortality and morbidity, and clinical and outcomes-based research related to anesthetic practices for women undergoing cesarean delivery.

    View details for DOI 10.1213/ANE.0b013e31826af982

    View details for Web of Science ID 000310762100020

    View details for PubMedID 22984153

  • 2012 Gerard W. Ostheimer Lecture - What's new in obstetric anesthesia? INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J. 2012; 21 (4): 348-356


    The aim of the 2012 "What's new in obstetric anesthesia?" review is to highlight important scientific and medical advances in the fields of obstetric anesthesiology, obstetrics and perinatology from literature published in 2011. This review will consider advances in the prevention and treatment of important obstetric and obstetric anesthesia-related morbidities, research relevant to the course of labor and electronic fetal monitoring, and advances in neuraxial analgesia and anesthesia for obstetric patients.

    View details for DOI 10.1016/j.ijoa.2012.08.005

    View details for Web of Science ID 000310409000009

    View details for PubMedID 22959260

  • Postpartum hemorrhage treated with a massive transfusion protocol at a tertiary obstetric center: a retrospective study INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Gutierrez, M. C., GOODNOUGH, L. T., Druzin, M., Butwick, A. J. 2012; 21 (3): 230-235


    A massive transfusion protocol may offer major advantages for management of postpartum hemorrhage. The etiology of postpartum hemorrhage, transfusion outcomes and laboratory indices in obstetric cases requiring the massive transfusion protocol were retrospectively evaluated in a tertiary obstetric center.We reviewed medical records of obstetric patients requiring the massive transfusion protocol over a 31-month period. Demographic, obstetric, transfusion, laboratory data and adverse maternal outcomes were abstracted.Massive transfusion protocol activation occurred in 31 patients (0.26% of deliveries): 19 patients (61%) had cesarean delivery, 10 patients (32%) had vaginal delivery, and 2 patients (7%) had dilation and evacuation. Twenty-six patients (84%) were transfused with blood products from the massive transfusion protocol. The protocol was activated within 2h of delivery for 17 patients (58%). Median [IQR] total estimated blood loss value was 2842 [800-8000]mL. Median [IQR] number of units of red blood cells, plasma and platelets from the massive transfusion protocol were: 3 [1.75-7], 3 [1.5-5.5], and 1 [0-2.5] units, respectively. Mean (SD) post-resuscitation hematologic indices were: hemoglobin 10.3 (2.4)g/dL, platelet count 126 (44)×10(9)/L, and fibrinogen 325 (125)mg/dL. The incidence of intensive care admission and peripartum hysterectomy was 61% and 19%, respectively.Our massive transfusion protocol provides early access to red blood cells, plasma and platelets for patients experiencing unanticipated or severe postpartum hemorrhage. Favorable hematologic indices were observed post resuscitation. Future outcomes-based studies are needed to compare massive transfusion protocol and non-protocol based transfusion strategies for the management of hemorrhage.

    View details for DOI 10.1016/j.ijoa.2012.03.005

    View details for Web of Science ID 000307685000005

    View details for PubMedID 22647592

  • Continuous spinal anesthesia for Cesarean hysterectomy and massive hemorrhage in a parturient with placenta increta CANADIAN JOURNAL OF ANESTHESIA-JOURNAL CANADIEN D ANESTHESIE Sultan, P., Hilton, G., Butwick, A., Carvalho, B. 2012; 59 (5): 473-477


    We present anesthetic management using a continuous spinal anesthesia (CSA) technique in a patient with placenta increta who underwent elective Cesarean hysterectomy with massive postpartum hemorrhage.A 34-yr-old parturient (G3P2) was scheduled for Cesarean delivery and possible hysterectomy at 35(+3) weeks due to suspected placenta accreta. Her body mass index was 21 kg·m(-2) and she had a reassuring airway. Inadvertent dural puncture occurred during combined spinal-epidural (CSE) placement, and a decision was made to thread the epidural catheter and utilize a CSA technique. Following delivery of a healthy infant, morbid adherence of the placenta to the myometrium was confirmed, and a supracervical hysterectomy was performed. Eight litres of blood loss occurred postpartum requiring resuscitation with crystalloid 3,800 mL, colloid 1,500 mL, red blood cells 16 units, fresh frozen plasma 16 units, platelets 4 units, and cryoprecipitate 1 unit. The patient developed pulmonary edema requiring conversion to general anesthesia. The patient's cardiovascular status was stable throughout surgery, and her lungs were mechanically ventilated for 18 hr postoperatively in the intensive care unit. The intrathecal catheter was removed 24 hr after placement. She developed no adverse neurological sequelae and reported no postdural puncture headache. The pathology report confirmed placenta increta.A CSA technique may be a viable option in the event of inadvertent dural puncture during planned CSE or epidural placement in patients with a reassuring airway undergoing Cesarean delivery. Although a catheter-based neuraxial technique is appropriate for Cesarean hysterectomy for abnormal placentation, conversion to general anesthesia may be required in the event of massive perioperative hemorrhage and fluid resuscitation.

    View details for DOI 10.1007/s12630-012-9681-0

    View details for Web of Science ID 000302574200007

    View details for PubMedID 22395824

  • Managing Patients with Abnormal Placentation: What Are the Best Anesthetic and Transfusion Strategies? ANESTHESIOLOGY Butwick, A. J. 2012; 116 (5): 1156-1157

    View details for DOI 10.1097/ALN.0b013e31824e60d1

    View details for Web of Science ID 000303199600029

    View details for PubMedID 22531257

  • Non-invasive haemoglobin measurement in patients undergoing elective Caesarean section BRITISH JOURNAL OF ANAESTHESIA Butwick, A., Hilton, G., Carvalho, B. 2012; 108 (2): 271-277


    The ability to measure haemoglobin (Hb) real-time and non-invasively offers important clinical value in the assessment of acute changes in maternal Hb during the peripartum period. This study evaluates the Masimo Rainbow SET(®) Radical-7 Pulse CO-Oximeter in a pregnant population undergoing Caesarean section (CS).Fifty patients undergoing elective CS were enrolled in this prospective, controlled study and followed for 48 h after surgery. Non-invasive Masimo Hb (SpHb) values were compared with laboratory Hb values from venous blood samples drawn at baseline, immediately post-CS, and 24 h post-CS using the Bland-Altman plots. Longitudinal analysis of SpHb changes over time was performed using mixed-effects regression modelling.For the comparison between SpHb and laboratory Hb, SpHb displayed a significant positive bias at baseline {1.22 g dl(-1) [95% confidence interval (CI): 0.89-1.54]} and at 24 h post-CS [1.36 g dl(-1) (95% CI: 1.04-1.68)]. The bias immediately post-CS was 0.14 g dl(-1) (95% CI: -0.18 to 0.46). The limits of agreement at baseline, immediately post-CS, and at 24 h post-CS were: -0.9 and 3.33, -2.35 and 2.56, and -0.55 and 3.27 g dl(-1), respectively. The mean decrease in SpHb from baseline to 48 h post-CS was ∼1 g dl(-1).The variability in bias and limits of agreements of the Rainbow SET(®) Radical-7 Pulse CO-Oximeter SpHb may limit its clinical utility for assessing Hb concentration in patients undergoing elective CS. Modifications are needed in the calibration of the device to improve accuracy and precision in an obstetric setting. The study was registered at (NCT01108471) before participant enrolment: URL=

    View details for DOI 10.1093/bja/aer373

    View details for Web of Science ID 000299414800015

    View details for PubMedID 22116296

  • How we treat: transfusion medicine support of obstetric services TRANSFUSION Goodnough, L. T., Daniels, K., Wong, A. E., Viele, M., Fontaine, M. F., Butwick, A. J. 2011; 51 (12): 2540-2548


    Obstetric services depend on the transfusion service (TS) to provide diagnostic testing and blood component therapy for clinical care pathways.We describe three quality improvement (QI) initiatives implemented to improve TS support of obstetric services.We implemented a pathway for patients requiring an ABO/Rh order for every admission to obstetric services, along with reconciliation of the daily hospital birth manifest and TS umbilical cord log to identify every woman eligible for RhIG. After assessment over 6 months, 21 (1%) of 2041 women lacked an admission ABO/Rh; all subsequently had ABO/Rh determinations. Umbilical cords were missing for eight (0.4%) mothers; four were D- and received RhIG. We developed algorithms for diagnostic blood ordering for patients deemed at "low,"moderate," or "high" risk of blood transfusion. A 27% reduction in total diagnostic test volumes and 24% reduction in charges was documented after compared to before implementation. We analyzed the impact of our massive transfusion protocol (MTP) on blood inventory management for 31 (0.25%) women undergoing 12,945 deliveries, representing 11% of 286 MTPs for all clinical services over a 32-month interval. O- uncrossmatched red blood cells (RBCs) represented 103 (24%) of 421 RBC units issued. Wastage rates of RBCs, plasma, and platelets ordered and issued in the MTPs were 0.7, 16, and 3%, respectively.QI initiatives for RhIG prophylaxis, diagnostic blood test ordering, and MTP improve TS support of obstetric services.

    View details for DOI 10.1111/j.1537-2995.2011.03152.x

    View details for Web of Science ID 000298340300006

    View details for PubMedID 21542850

  • Epidural Catheter Removal in Patients on Warfarin Thromboprophylaxis A More Cautious Interpretation of Results Required? REGIONAL ANESTHESIA AND PAIN MEDICINE Carvalho, B., Mariano, E. R., Butwick, A. J. 2011; 36 (6): 632-632

    View details for DOI 10.1097/AAP.0b013e31822e0c7e

    View details for Web of Science ID 000296532100021

    View details for PubMedID 22024706

  • An In Vitro Investigation of the Coagulation Effects of Exogenous Oxytocin Using Thromboelastography in Healthy Parturients ANESTHESIA AND ANALGESIA Butwick, A., Harter, S. 2011; 113 (2): 323-326


    We investigated the coagulation effects in vitro of exogenous oxytocin in whole blood of healthy term parturients.Thromboelastography (TEG®) was performed on kaolin-activated citrated blood samples from 25 healthy, term, nonlaboring parturients. We compared the in vitro effects on the maternal thromboelastographic profile of 3 different exogenous oxytocin concentrations (22.5, 30.1, and 32.9 μU/mL) and a control (0 μU/mL). These exogenous oxytocin concentrations were chosen to approximate maternal plasma oxytocin concentrations during elective cesarean delivery, vaginal delivery, and nonelective cesarean delivery, respectively.Increasing the oxytocin concentration was significantly associated with hypercoagulable effects as observed with TEG® (decreasing reaction time, clot formation time, and Tmax; increasing α angle and maximum rate of thrombus generation). Compared with control samples, the median percentage change (interquartile range) in TEG® values for samples with the highest exogenous oxytocin concentration (32.9 μU/mL) was largest for reaction time: -40.3% (-45.8%, -22.2%); and Tmax: -39.2% (-42.9%, -28.5%).The results of this in vitro investigation suggest that exogenous oxytocin is associated with modest hypercoagulable effects in the maternal blood of healthy term parturients.

    View details for DOI 10.1213/ANE.0b013e3182222a82

    View details for Web of Science ID 000293064500019

    View details for PubMedID 21642611

  • The Proseal laryngeal mask airway and elective caesarean section ANAESTHESIA AND INTENSIVE CARE Dyer, R. A., James, M. F., Butwick, A. J., Carvalho, B. 2011; 39 (4): 760-761

    View details for Web of Science ID 000293264000036

    View details for PubMedID 21823396

  • Non-invasive measurement of hemoglobin during cesarean hysterectomy: a case series INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Hilton, G., Riley, E. T., Carvalho, B. 2011; 20 (3): 240-245


    Obstetric patients diagnosed with abnormal placentation (placenta accreta, increta or percreta) are at increased risk of major postpartum hemorrhage and cesarean hysterectomy. Obstetric anesthesiologists are primarily involved in intraoperative transfusion management in these cases. Hemoglobin assessment is invaluable for assisting transfusion decision-making during the acute period of obstetric hemorrhage. However, laboratory and point-of-care tests of hemoglobin concentration are time-dependent and intermittent, and do not provide a real-time assessment of change during the acute phase of blood loss. A new non-invasive hemoglobin monitor has been introduced recently, which provides real-time measurement of hemoglobin values (SpHb) using multi-wavelength pulse co-oximetry. We present a review of five patients with suspected abnormal placentation who received SpHb monitoring during cesarean hysterectomy at our institution. We discuss the potential clinical utility of non-invasive hemoglobin monitoring for pregnant patients at high risk of obstetric hemorrhage, and the potential role of SpHb in guiding transfusion therapy.

    View details for DOI 10.1016/j.ijoa.2011.03.009

    View details for Web of Science ID 000293042800009

    View details for PubMedID 21640577

  • Oxytocin for labour and caesarean delivery: implications for the anaesthesiologist CURRENT OPINION IN ANESTHESIOLOGY Dyer, R. A., Butwick, A. J., Carvalho, B. 2011; 24 (3): 255-261


    The implications of the obstetric use of oxytocin for obstetric anaesthesia practice are summarised. The review focuses on recent research on the uterotonic effects of oxytocin for prophylaxis and management of uterine atony during caesarean delivery.Oxytocin remains the first-line agent in the prevention and management of uterine atony. In-vitro and in-vivo studies show that prior exposure to oxytocin induces uterine muscle oxytocin receptor desensitization. This may influence oxytocin dosing for adequate uterine tone following delivery. Oxytocin has important cardiovascular side-effects (hypotension, tachycardia and myocardial ischaemia). Recent studies suggest that the effective dose of oxytocin for prophylaxis against uterine atony during caesarean delivery is significantly lower than the 5-10 IU historically used by anaesthesiologists. Slow administration of small bolus doses of oxytocin minimises maternal haemodynamic disturbance. Continuous oxytocin infusions are recommended for maintaining uterine tone after bolus administration, although ideal infusion rates are still to be established. The efficacy of the long-acting oxytocin analogue carbetocin requires further investigation. Recommendations are presented for oxytocin dosing during caesarean delivery.Oxytocin remains the first-line uterotonic after vaginal and caesarean delivery. Recent research elucidates the therapeutic range of oxytocin during caesarean delivery, as well as receptor desensitization. Evidenced-based protocols for the prevention and treatment of uterine atony during caesarean delivery are recommended.

    View details for DOI 10.1097/ACO.0b013e328345331c

    View details for Web of Science ID 000289974800004

    View details for PubMedID 21415725

  • The effectiveness of preemptive sphenopalatine ganglion block on postoperative pain and functional outcomes after functional endoscopic sinus surgery 56th Annual Fall Scientific Meeting of the American-Rhinologic-Society (ARS) Cho, D., Drover, D. R., Nekhendzy, V., Butwick, A. J., Collins, J., Hwang, P. H. WILEY-BLACKWELL. 2011: 212–18


    The sphenopalatine ganglion block (SPGB) with local anesthetic is used to treat facial pain and headache of various etiologies; it has been widely used during functional endoscopic sinus surgery (FESS). The purpose of this study was to investigate whether preemptive SPGB may positively impact postoperative pain and functional outcomes after FESS.A prospective, double-blind, randomized, placebo-controlled study was performed. A total of 60 patients (18-70 years), undergoing general anesthesia for bilateral FESS, were randomly assigned to receive SPGB with either 2 mL 0.25% bupivacaine with epinephrine 1:100,000 (BP, treatment group) or normal saline (NS, control group). SPGB was performed preemptively 10 minutes before the start of surgery. Preoperative and postoperative (day 0, day 7, and day 30) visual analog pain scale, Sino-Nasal Outcome Test (SNOT-20), computed tomography (CT) and endoscopic scores were compared between the 2 groups.A total of 29 patients were enrolled in BP, and 27 were enrolled in NS. Three patients withdrew from the study, and 1 was withdrawn by the investigator due to severe hypertension after induction of anesthesia. There were no differences in patient demographic characteristics between the study groups. On day 7, the mean visual analog pain scales were 1.12 ± 0.3 in NS and 0.48 ± 0.23 in BP (p = 0.053). There were no statistical differences in other outcome measures (SNOT-20, CT and endoscopic scores) between the 2 groups.A limited trend toward reduced postoperative pain after FESS was noted with bupivacaine compared to saline, but statistical significance was not achieved. Preemptive SPGB may offer sinonasal symptomatic benefits for patients undergoing FESS, but larger studies are warranted.

    View details for DOI 10.1002/alr.20040

    View details for Web of Science ID 000308912700014

    View details for PubMedID 22287376

  • The Association Between Thromboelastographic Parameters and Total Estimated Blood Loss in Patients Undergoing Elective Cesarean Delivery ANESTHESIA AND ANALGESIA Butwick, A., Ting, V., Ralls, L. A., Harter, S., Riley, E. 2011; 112 (5): 1041-1047


    In this study, we assessed the relationship between coagulation parameters using kaolin-activated thromboelastography (TEG®) and total estimated blood loss (EBL) in patients undergoing elective cesarean delivery (CD).TEG® parameters were recorded in 52 patients before and after elective CD. Laboratory markers of coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen) were also assessed in a smaller subset (21 patients). Correlation and linear regression analysis was used to assess the relationship among TEG® parameters, relevant clinical variables, and total EBL. Secondary analysis included comparisons of TEG® and coagulation profiles pre-CD versus post-CD.EBL weakly correlated with percentage change in maximum amplitude (r=0.3; P=0.04) and post-CD maximum rate of thrombus generation (r=0.31; P=0.02). Post-CD values for split point, reaction time, time to maximum rate of thrombin generation, prothrombin time, and activated partial thromboplastin time were significantly increased compared with baseline values (P<0.05). Post-CD α angle, maximum amplitude, total thrombus generation, fibrinogen, and platelet counts were significantly decreased compared with baseline values (P<0.05).There is a weak association between clot strength (as assessed by kaolin-activated TEG®) and EBL in patients undergoing elective CD under neuraxial anesthesia, and a modest reduction in the degree of maternal hypercoagulability occurs in the early postpartum period after elective CD.

    View details for DOI 10.1213/ANE.0b013e318210fc64

    View details for Web of Science ID 000289785100009

    View details for PubMedID 21474664

  • The postoperative anaesthetic review. Journal of perioperative practice Sultan, P., Jigajinni, S., McGlennan, A., Butwick, A. 2011; 21 (4): 135-139


    An anaesthetic preoperative assessment for all patients is the standard of care in UK hospitals. The Royal College of Anaesthetists (RCoA) 2009 guidelines state that a postoperative visit, within 24 hours following surgery, is recommended for patients only in certain circumstances. This article critiques these guidelines and explores factors which must be taken into consideration when deciding whether or not anaesthetists should routinely visit their patients after they leave the recovery area. We discuss the physiological rationale for performing a postoperative anaesthetic visit; the identification of post-operative morbidity including provision of adequate post-operative analgesia; patient benefits; limitations of performing postoperative review, and the implications that expanding anaesthetists' responsibilities as perioperative physicians has had upon anaesthetic training and service provision. Finally, this article offers an alternative model for deciding when to perform a post-anaesthetic visit.

    View details for PubMedID 21560554

  • Anticoagulant and antithrombotic drugs in pregnancy: what are the anesthetic implications for labor and cesarean delivery? JOURNAL OF PERINATOLOGY Butwick, A. J., Carvalho, B. 2011; 31 (2): 73-84


    Neuraxial anesthetic techniques are commonly used during the peripartum period to provide effective pain relief for labor and anesthesia during cesarean delivery. Major neurologic complications are rare after neuraxial anesthesia; however, spinal hematoma is associated with catastrophic neurologic outcomes (including lower-limb paralysis). Anticoagulant and antithrombotic drugs can increase the risk of spinal hematoma after neuraxial anesthesia, and better understanding of the pharmacokinetics and pharmacodynamics of anticoagulants has led to greater appreciation for withholding anticoagulation before and after neuraxial anesthesia. A number of national anesthetic societies have produced guidelines for performing neuraxial anesthesia in patients receiving anticoagulation. However, there is limited information about anesthetic implications of anticoagulation during the peripartum period. This article will review the risks of spinal hematoma after neuraxial anesthesia in pregnant patients; current guidelines for neuraxial anesthesia for anticoagulated patients; and relevant pharmacological data of specific anticoagulant and antithrombotic drugs in pregnancy.

    View details for DOI 10.1038/jp.2010.64

    View details for Web of Science ID 000286808100001

    View details for PubMedID 20559281

  • Retrospective analysis of anesthetic interventions for obese patients undergoing elective cesarean delivery JOURNAL OF CLINICAL ANESTHESIA Butwick, A., Carvalho, B., Danial, C., Riley, E. 2010; 22 (7): 519-526


    To examine the relationship between body mass index (BMI), perioperative times, and anesthetic interventions in patients undergoing elective cesarean delivery.Retrospective chart review.University-affiliated hospital.All patients were ranked according to BMI (kg/m(2)) at the time of delivery. The BMI groups were designated a priori: ≤ 29.9 kg/m(2) (Group C); 30-34.9 kg/m(2) (Group I); 35-39.9 kg/m(2) (Group II), and ≥ 40 kg/m(2) (Group III). One hundred patients (25 pts per group) underwent elective cesarean delivery. Data collected included anesthetic technique, perioperative times, anesthesia-related costs, and neonatal outcomes.A higher percentage of Group III patients (60%) received combined spinal-epidural (CSE) anesthesia than did Group C or Group I (18% and 16%, respectively; P < 0.05). The total intraoperative period was significantly longer in Group III (101 min) compared with Groups C, I, and II (81 min, 90 min, and 92 min, respectively; P < 0.05). Total intraoperative time increased significantly with BMI (R = 0.394 kg/m(2); P < 0.001). The highest anesthesia-related costs during the study were generated by patients with BMI ≥ 40 kg/m(2).Our single-center experience showed that choice of anesthetic technique (CSE vs. spinal anesthesia) varies according to obesity class. Longer intraoperative periods must be considered in deciding upon the mode of anesthesia for patients with BMI ≥ 40 kg/m(2) who undergo elective cesarean delivery.

    View details for DOI 10.1016/j.jclinane.2010.01.005

    View details for Web of Science ID 000284791000006

    View details for PubMedID 21056808

  • ST depression at caesarean section and the relation to oxytocin dose. A randomised controlled trial BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY Butwick, A., Dyer, R. 2010; 117 (9): 1165-1165
  • Minimum effective bolus dose of oxytocin during elective Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B. 2010; 105 (1): 92-93
  • Minimum effective bolus dose of oxytocin during elective Caesarean delivery - Conflict of interest BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Carvalho, B. 2010; 104 (6): 783-785
  • Neuraxial anesthesia in obstetric patients receiving anticoagulant and antithrombotic drugs INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Carvalho, B. 2010; 19 (2): 193-201

    View details for DOI 10.1016/j.ijoa.2009.06.008

    View details for Web of Science ID 000277553700012

    View details for PubMedID 20202816

  • Minimum effective bolus dose of oxytocin during elective Caesarean delivery BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Coleman, L., Cohen, S. E., Riley, E. T., Carvalho, B. 2010; 104 (3): 338-343


    The aim of this study was to determine the lowest effective bolus dose of oxytocin to produce adequate uterine tone (UT) during elective Caesarean delivery (CD).Seventy-five pregnant patients undergoing elective CD under spinal anaesthesia were randomized to receive oxytocin (0.5, 1, 3, 5 units) or placebo. UT was assessed by a blinded obstetrician as either adequate or inadequate, and using a verbal numerical scale score (0-10; 0, no UT; 10, optimal UT) at 2, 3, 6, and 9 min after oxytocin administration. Minimum effective doses of oxytocin were analysed (ED(50) and ED(95)) using logistic regression. Oxytocin-related side-effects (including hypotension) were recorded.There were no significant differences in the prevalence of adequate UT among the study groups at 2 min (73%, 100%, 93%, 100%, and 93% for 0, 0.5, 1, 3, and 5 units oxytocin, respectively). The high prevalence of adequate UT after placebo and low-dose oxytocin precluded determination of the ED(50) and ED(95). UT scores were significantly lower in patients receiving 0 unit oxytocin at 2 and 3 min compared with 3 and 5 units oxytocin (P<0.05, respectively). The prevalence of hypotension was significantly higher after 5 units oxytocin vs 0 unit at 1 min (47% vs 7%; P=0.04).The routine use of 5 units oxytocin during elective CD can no longer be recommended, as adequate UT can occur with lower doses of oxytocin (0.5-3 units).

    View details for DOI 10.1093/bja/aeq004

    View details for Web of Science ID 000274485900011

    View details for PubMedID 20150347

  • Retrospective analysis of transfusion outcomes in pregnant patients at a tertiary obstetric center INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J., Aleshi, P., Fontaine, M., Riley, E. T., GOODNOUGH, L. T. 2009; 18 (4): 302-308


    The decision to use red blood cell transfusion and/or blood products (fresh frozen plasma, platelets, cryoprecipitate) to manage obstetric hemorrhage or treat postpartum anemia is often made empirically by physicians. We performed a retrospective study to review transfusion outcomes in pregnant and postpartum patients at a large obstetric center.A retrospective, observational study was performed of obstetric in-patients who received red blood cell transfusion and/or blood products over a one-year period. Data abstracted included transfusion data, pre-transfusion hemoglobin (Hb) and lowest recorded (nadir) Hb, and maternal and neonatal outcomes.During the study period, 74 patients received transfusion therapy (1.4%). Pre-transfusion and nadir Hb values were 7.6 g/dL and 7.0 g/dL respectively. Median [IQR] total red blood cells transfused were 2 units [2-3], with 41 (55%) patients receiving 1-2 units. Based on chart review, no specific indications for transfusion were identified in 25 patients (34%), and 13 patients (18%) had undetected postpartum anemia (Hb values <8.2 g/dL) at least 24h after delivery.More formal assessment and documentation of the etiologic factors associated with transfusion management in pregnant patients is advised. In addition, the identification and management of undetected postpartum anemia is underappreciated.

    View details for DOI 10.1016/j.ijoa.2009.02.005

    View details for Web of Science ID 000271135300002

    View details for PubMedID 19628384

  • Obstetric hemorrhage during an exit procedure for severe fetal airway obstruction 40th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Butwick, A., Aleshi, P., Yamout, I. SPRINGER. 2009: 437–42


    To report a case of massive obstetric hemorrhage occurring during Cesarean delivery for an ex utero intrapartum treatment (EXIT) procedure. Methods to optimize the anesthetic, obstetric, and perinatal management are discussed.A healthy parturient underwent an urgent EXIT procedure at 32 weeks gestation for a giant fetal neck mass. During the intraoperative period, severe intraoperative hemorrhage occurred from the site of the uterine incision. No evidence of placental bleeding, premature placental separation, or inadequate uterine relaxation was observed during the perioperative period. Placement of a uterine stapling device was unsuccessful in achieving adequate surgical hemostasis. Initial attempts with laryngoscopy and rigid bronchoscopy to secure the fetal airway on placental support were unsuccessful, and early termination of placental support was deemed necessary due to the severity of maternal blood loss. After full delivery of the neonate and termination of placental support, neonatal ventilation with bag-mask ventilation was achieved and successful endotracheal intubation occurred during repeat bronchoscopy.The risk of obstetric hemorrhage due to uterine relaxation and inadequate surgical hemostasis in patients undergoing EXIT procedures is poorly reported. To reduce adverse maternal and neonatal outcomes, the premature termination of placental support during EXIT procedures may be required in the setting of severe obstetric hemorrhage.

    View details for DOI 10.1007/s12630-009-9092-z

    View details for Web of Science ID 000265940000007

    View details for PubMedID 19396506

  • A survey of perioperative and postoperative anesthetic practices for cesarean delivery. Anesthesiology research and practice Aiono-Le Tagaloa, L., Butwick, A. J., Carvalho, B. 2009; 2009: 510642-?


    The aim of this survey was to review cesarean delivery anesthetic practices. An online survey was sent to members of the Society of Obstetric Anesthesia and Perinatology (SOAP). The mode of anesthesia, preferred neuraxial local anesthetic and opioid agents, postoperative analgesic regimens, and monitoring modalities were assessed. 384 responses from 1,081 online survey requests were received (response rate = 36%). Spinal anesthesia is most commonly used for elective cesarean delivery (85% respondents), with 90% of these respondents preferring hyperbaric bupivacaine 0.75%. 79% used intrathecal fentanyl and 77% used morphine (median [range] dose 200 mcg [50-400]). 91% use respiratory rate, 61% use sedation scores, and 30% use pulse oximetry to monitor for postoperative respiratory depression after administration of neuraxial opioids. Postoperative analgesic regimens include: nonsteroidal anti-inflammatory agents, acetaminophen, oxycodone, and hydrocodone by 81%, 45%, 25%, and 27% respondents respectively. The majority of respondents use spinal anesthesia and neuraxial opioids for cesarean delivery anesthesia. There is marked variability in practices for monitoring respiratory depression postdelivery and for providing postoperative analgesia. These results may not be indicative of overall practice in the United States due to the select group of anesthesiologists surveyed and the low response rate.

    View details for DOI 10.1155/2009/510642

    View details for PubMedID 21217809

  • Vaginal twin delivery: a survey and review of location, anesthesia coverage and interventions 38th Annual Meeting of the Society-for-Obstetric-Anesthesia-and-Perinatology Carvalho, B., Saxena, A., Butwick, A., Macario, A. CHURCHILL LIVINGSTONE. 2008: 212–16


    Twin pregnancies are associated with increased perinatal morbidity and mortality. No consensus exists whether vaginal twin delivery should take place in the labor room or operating room, or whether anesthesiologists should be present. We surveyed members of the California Society of Anesthesiologists (CSA) to review management of vaginal twin delivery, and examined anesthetic intervention retrospectively at our institution.230 CSA members were asked to complete an online survey on location of vaginal twin delivery in their institution and whether they were required to be present throughout. We then retrospectively reviewed charts of vaginal twin deliveries at our institution over a 36-month period to analyze frequency and type of anesthetic intervention.The online survey response rate was 58%; 64% of responders reported that vaginal twin deliveries were performed in the operating room and 55% that an anesthesiologist was present. There was a strong association between anesthesiologist's presence and delivery in the operating room (OR 7; 95% CI 3-20). We reviewed 81 charts of women who underwent vaginal twin delivery. The median (range) time that the anesthesiologist was present for each delivery was 60 (20-380) min. Of women undergoing vaginal twin delivery, 27% required anesthetic intervention during the second stage of labor with 6% having emergency cesarean delivery.There is a lack of consensus regarding the appropriate location for vaginal twin delivery and the role of anesthesiologists. A significant percentage of women undergoing vaginal twin delivery in our institution received anesthetic intervention in the immediate delivery period.

    View details for DOI 10.1016/j.ijoa.2007.04.004

    View details for Web of Science ID 000257844200003

    View details for PubMedID 17881218

  • Intraoperative forced air-warming during cesarean delivery under spinal anesthesia does not prevent maternal hypothermia ANESTHESIA AND ANALGESIA Butwick, A. J., Lipman, S. S., Carvalho, B. 2007; 105 (5): 1413-1419


    Prewarming and intraoperative warming with forced air-warming systems prevent perioperative hypothermia and shivering in patients undergoing elective cesarean delivery with epidural anesthesia. We tested the hypothesis that intraoperative lower body forced air-warming prevents hypothermia in patients undergoing elective cesarean delivery with spinal anesthesia.Thirty healthy patients undergoing cesarean delivery with spinal anesthesia were randomly assigned to forced air-warming or control groups (identical cover applied with forced air-warming unit switched off). A blinded investigator assessed oral temperature, shivering, and thermal comfort scores at 15-min intervals until discharge from the postanesthetic care unit. Umbilical cord blood gases and Apgar scores were also measured after delivery.The maximum core temperature changes were similar in the two groups (-1.3 degrees C +/- 0.4 degrees C vs -1.3 degrees C +/- 0.3 degrees C for the forced air-warming group and control group, respectively; P = 0.8). Core hypothermia (< or =35.5 degrees C) occurred in 8 of 15 patients receiving forced air-warming and in 10 of 15 unwarmed patients (P = 0.5). The incidence and severity of shivering did not significantly differ between groups. Umbilical cord blood gases and Apgar scores were similar in both groups (P = NS).We conclude that intraoperative lower body forced air-warming does not prevent intraoperative hypothermia or shivering in women undergoing elective cesarean delivery with spinal anesthesia.

    View details for DOI 10.1213/01.ane.0000286167.96410.27

    View details for Web of Science ID 000250317500039

    View details for PubMedID 17959975

  • Can we improve maternal outcome for high-risk obstetric patients? INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B. 2007; 16 (4): 311-313

    View details for DOI 10.1016/j.ijoa.2007.04.005

    View details for Web of Science ID 000250284800003

    View details for PubMedID 17698338

  • Successful spinal blockade in a parturient with myotonia congenita INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A. J. 2007; 16 (3): 292-293

    View details for DOI 10.1016/j.ijoa.2007.01.003

    View details for Web of Science ID 000248160500022

    View details for PubMedID 17451935

  • Neuraxial anesthesia for cesarean delivery in a parturient with type 1 von Willebrand disease and scoliosis JOURNAL OF CLINICAL ANESTHESIA Butwick, A. J., Carvalho, B. 2007; 19 (3): 230-233


    We present the case of a parturient with von Willebrand disease and scoliosis who required cesarean delivery. Neuraxial anesthesia was used for the patient. The indications for neuraxial anesthesia with regard to type 1 von Willebrand disease are reviewed.

    View details for DOI 10.1016/j.jclinane.2006.08.013

    View details for Web of Science ID 000247128200014

    View details for PubMedID 17531735

  • The effect of colloid and crystalloid preloading on thromboelastography prior to Cesarean delivery Annual Meeting of the Obstetric-Anaesthetists-Association Butwick, A., Carvalho, B. SPRINGER. 2007: 190–95


    Fluid preloading with colloids reduces hypotension after spinal anesthesia for Cesarean delivery more effectively than crystalloids. However, the effects of fluid preloading regimens on coagulation in pregnant patients remain unresolved. The aim of this study was to compare the effects on coagulation of fluid preloading with 6% hydroxyethyl starch (HES) and lactated Ringer's (LR) solution using thromboelastography (TEG) with kaolin-activated whole blood in healthy pregnant patients prior to spinal anesthesia for Cesarean delivery.After obtaining Ethics committee approval, 30 parturients were prospectively randomized prior to spinal anesthesia for elective Cesarean delivery to receive fluid preloading with either 1500 mL LR or 500 mL 6% HES over 30 min. Thromboelastography was performed immediately prior to and after fluid preloading. Standard TEG parameters were analyzed in terms of r time (min), k time (min), alpha angle (degrees) and maximum amplitude (mm).Group HES had statistically significant longer reaction times (r) and clot formation times (k) after fluid loading compared to baseline values (P < 0.05 respectively), although these post-fluid loading TEG parameters remained within a normal reference range. No significant differences in TEG values were seen after preloading within the LR group.Fluid preloading with 500 mL 6% HES in healthy parturients produced mild coagulation effects, as measured with TEG, prior to spinal anesthesia for Cesarean delivery. No significant effects on coagulation with TEG were observed following preloading with 1500 mL LR.

    View details for Web of Science ID 000245113600005

    View details for PubMedID 17331930

  • Remifentanil patient-controlled analgesia in labor ANESTHESIA AND ANALGESIA Butwick, A., Carvalho, B. 2006; 102 (1): 333-333

    View details for Web of Science ID 000234275700071

    View details for PubMedID 16368862

  • Recombinant factor VIIa for life-threatening post-partum haemorrhage BRITISH JOURNAL OF ANAESTHESIA Butwick, A. J., Riley, E. T. 2005; 95 (4): 558-558
  • Maternal and neonatal side-effects of remifentanil patient-controlled analgesia in labour BRITISH JOURNAL OF ANAESTHESIA Volikas, I., Butwick, A., Wilkinson, C., Pleming, A., Nicholson, G. 2005; 95 (4): 504-509


    Remifentanil has been suggested as an ideal opioid for patient-controlled analgesia (PCA) in labour, but the safety profile has not been established. The aims of this preliminary prospective observational study were to investigate the maternal side-effects and early neonatal effects, and to assess the placental transfer of remifentanil PCA during labour.Women with no known obstetric complications or contraindication to remifentanil were recruited (n=50). Remifentanil was administered at a bolus dose of 0.5 microg kg(-1) and a lockout period of 2 min. A visual analogue scale was used to assess pain, nausea and itching. Maternal observations were recorded hourly and fetal heart rate trace was assessed every 2 h. Umbilical cord gases, 1 and 5 min Apgar scores and neurological evaluation of the neonate were recorded. Maternal venous blood and umbilical artery and vein cord blood samples were collected for analysis of remifentanil concentration.Fifty women enrolled in the study (24 multiparous, 26 primiparous). There was no evidence of cardiovascular instability or respiratory depression. Pain scores decreased significantly, but there was no significant change in nausea after initiating the PCA. A statistically significant increase in itching was found to be clinically mild and 22 women were slightly drowsy (95% confidence interval [CI], 30-58.7%) but alert to voice. Ten fetal heart rate traces demonstrated changes in the first 20 min, but did not require intervention (95% CI, 10-33.7%). The median 1 and 5 min Apgar scores were 9. The mean umbilical cord gases and neurological examination were within normal limits. Maternal vein and umbilical vein cord samples demonstrated placental transfer of remifentanil, and small amounts were detected in umbilical artery samples.At the bolus dose used remifentanil PCA has an acceptable level of maternal side-effects and minimal effect on the neonate. Remifentanil crosses the placenta and appears to be either rapidly metabolized or redistributed in the neonate.

    View details for DOI 10.1093/bja/aei219

    View details for Web of Science ID 000231921400013

    View details for PubMedID 16113038

  • Management of pregnancy in a patient with beta thalassaemia major INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Butwick, A., Findley, I., Wonke, B. 2005; 14 (4): 351-354


    beta thalassaemia is one of the world's most wide-spread monogenetic disorders. Advances in the management of beta thalassaemia major by extensive blood transfusions and chelation therapy have improved survival of patients into adult life. Due to the prolonged life expectancy and improvements in quality of life, pregnancy has now become an important issue for patients and clinicians. We report a case of a pregnant patient with beta thalassaemia major who underwent a successful caesarean section under spinal anaesthesia. The multidisciplinary approach to management of beta thalassaemia major and pregnancy is discussed.

    View details for DOI 10.1016/j.ijoa.2005.02.002

    View details for Web of Science ID 000232874100019

    View details for PubMedID 16140004

  • Ventilator-assisted nasotracheal intubation ANAESTHESIA Butwick, A., Garewal, D. 2004; 59 (2): 197-197

    View details for Web of Science ID 000188226600028

    View details for PubMedID 14725535

  • A pilot study of the effect of the Queen's Square external bladder stimulator on urinary retention after knee replacement surgery ANAESTHESIA Butwick, A., Carter, P., Dolin, S. J. 2003; 58 (6): 587-591


    Postoperative urinary retention remains an important problem after major orthopaedic surgery and can increase morbidity. External vibration applied to the suprapubic region has improved bladder emptying and urinary symptoms in patients with neurogenic bladders. Forty-three patients undergoing elective major knee surgery were randomly assigned to receive either a Queen's Square bladder stimulator or placebo device for 24 h postoperatively. No statistically significant differences in rates of urinary retention could be demonstrated in the bladder stimulator group compared to the placebo group (41% and 33%, respectively). There were no differences between the two groups when analysed for prostatic symptoms, type and effectiveness of analgesia and fluid balance. We conclude that, while the Queen's Square external bladder stimulator may be effective in treating chronic urinary retention associated with a neurogenic bladder, it does not appear to be effective in preventing postoperative urinary retention.

    View details for Web of Science ID 000183025400017

    View details for PubMedID 12846628