Bio

Research & Scholarship

Current Research and Scholarly Interests


Our obstetric anesthesia group is interested in a variety of topics including the efficacy and mechanism of action of spinal and epidural opioids for production of analgesia during labor, and the functionality of epidural analgesia for labor pain relief. Recently, techniques have been directed at providing excellent analgesia with no or minimal motor blockade or side effects. We have performed clinical and volunteer studies to examine the effects of spinal sufentanil (a short-acting synthetic opioid) given to relieve labor pain, and the potential benefits of "walking epidurals" - a technique for epidural analgesia using such dilute solutions of local anesthetics combined with opioids that patients are able to ambulate.

Teaching

2013-14 Courses


Publications

Journal Articles


  • Response times for emergency cesarean delivery: use of simulation drills to assess and improve obstetric team performance JOURNAL OF PERINATOLOGY Lipman, S. S., Carvalho, B., Cohen, S. E., Druzin, M. L., Daniels, K. 2013; 33 (4): 259-263

    Abstract

    We documented time to key milestones and determined reasons for transport-related delays during simulated emergency cesarean.Prospective, observational investigation of delivery of care processes by multidisciplinary teams of obstetric providers on the labor and delivery unit at Lucile Packard Children's Hospital, Stanford, CA, USA, during 14 simulated uterine rupture scenarios. The primary outcome measure was the total time from recognition of the emergency (time zero) to that of surgical incision.The median (interquartile range) from time zero until incision was 9?min 27?s (8:55 to 10:27?min:s).In this series of emergency cesarean drills, our teams required approximately nine and a half minutes to move from the labor room to the nearby operating room (OR) and make the surgical incision. Multiple barriers to efficient transport were identified. This study demonstrates the utility of simulation to identify and correct institution-specific barriers that delay transport to the OR and initiation of emergency cesarean delivery.

    View details for DOI 10.1038/jp.2012.98

    View details for Web of Science ID 000316833300002

    View details for PubMedID 22858890

  • Transport Decreases the Quality of Cardiopulmonary Resuscitation During Simulated Maternal Cardiac Arrest ANESTHESIA AND ANALGESIA Lipman, S. S., Wong, J. Y., Arafeh, J., Cohen, S. E., Carvalho, B. 2013; 116 (1): 162-167

    Abstract

    The purpose of this study was to compare cardiopulmonary resuscitation (CPR) for simulated maternal cardiac arrest rendered during transport to the operating room with that rendered while stationary in the labor room. We hypothesized that the quality of CPR would deteriorate during transport.Twenty-six teams composed of 2 providers (obstetricians, nurses, or anesthesiologists) were randomized to perform CPR on the Laerdal Resusci Anne SkillReporter™ mannequin during transport or while stationary. The primary outcome measure was the percentage of correctly delivered compressions, defined as compression rate ?100 beats per minute, correct sternal hand placement, compression depth ?1.5 inches (3.8 cm), and proper release. Secondary outcomes included interruptions in compressions, position of providers relative to the mannequin during the transport phase, and ventilation tidal volume.The median (interquartile range) percentage of correctly rendered compressions during phase II was 32% (10%-63%) in the transport group and 93% (58%-100%) in the stationary group (P = 0.002, 95% confidence interval of mean difference = 22%-58%). The median (interquartile range) compression rates were 124 (110-140) beats per minute in the transport group and 123 (115-132) beats per minute in the stationary group (P = 0.531). Interruptions in CPR were observed in 92% of transport and 7% of stationary drills (P < 0.001, 95% confidence interval of difference = 61%-92%). During transport, 18 providers kneeled next to the mannequin, 2 straddled the mannequin, and 4 ran alongside the gurney. Median (interquartile range) tidal volume was 270 (166-430) mL in the transport group and 390 (232-513) mL in the stationary group (P = 0.03).Our data confirm our hypothesis and demonstrate that transport negatively affects the overall quality of resuscitation on a mannequin during simulated maternal arrest. These findings, together with previously published data on transport-related delays when moving from the labor room to the operating room further strengthen recommendations that perimortem cesarean delivery should be performed at the site of maternal cardiac arrest.

    View details for DOI 10.1213/ANE.0b013e31826dd889

    View details for Web of Science ID 000313145300020

    View details for PubMedID 23223106

  • Measuring the labor pain experience: delivery still far off INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Cohen, S. E. 2013; 22 (1): 6-9

    View details for DOI 10.1016/j.ijoa.2012.10.002

    View details for Web of Science ID 000315829600002

    View details for PubMedID 23182607

  • Intrathecal fentanyl added to bupivacaine and morphine for cesarean delivery may induce a subtle acute opioid tolerance INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Drover, D. R., Ginosar, Y., Cohen, S. E., Riley, E. T. 2012; 21 (1): 29-34

    Abstract

    Previous studies have demonstrated that the addition of intrathecal fentanyl to a spinal anesthetic for cesarean delivery improves intraoperative analgesia. However, intrathecal fentanyl may induce acute tolerance to opioids. The objective of this study was to investigate whether the addition of intrathecal fentanyl to spinal anesthesia with intrathecal morphine increases postoperative analgesic requirements and pain scores.In this randomized, double-blinded study, 40 women having elective cesarean delivery were enrolled. Patients received spinal anesthesia with hyperbaric bupivacaine 12 mg, morphine 200 ?g, and fentanyl 0, 5, 10 or 25 ?g. Each patient received intravenous patient-controlled analgesia morphine for 24h postoperatively. Outcome measures included postoperative morphine usage and pain scores, as well as intraoperative pain, nausea, hypotension and vasopressor use.Total morphine use over the 24-h post-spinal study period was similar among the study groups (P=0.129). Postoperative pain scores were higher in patients receiving fentanyl 5, 10 and 25 ?g compared to fentanyl 0 ?g control group (P=0.003).The study results suggest that intrathecal fentanyl may induce acute tolerance to intrathecal morphine. However, because there was no difference in postoperative analgesia requirement and the difference in pain scores was small, the clinical significance of this finding is uncertain.

    View details for DOI 10.1016/j.ijoa.2011.09.002

    View details for Web of Science ID 000301325800006

    View details for PubMedID 22100823

  • Labor Room Setting Compared With the Operating Room for Simulated Perimortem Cesarean Delivery A Randomized Controlled Trial OBSTETRICS AND GYNECOLOGY Lipman, S., Daniels, K., Cohen, S. E., Carvalho, B. 2011; 118 (5): 1090-1094

    Abstract

    To compare the labor room and operating room for perimortem cesarean delivery during simulated maternal arrests occurring outside the operating room. We hypothesized transport to the operating room for perimortem cesarean delivery would delay incision and other important resuscitation milestones.We randomized 15 teams composed of obstetricians, nurses, anesthesiologists, and neonatal staff to perform perimortem cesarean delivery in the labor room or operating room. A manikin with an abdominal model overlay was used for simulated cesarean delivery. The scenario began in the labor room with maternal cardiopulmonary arrest and fetal bradycardia. The primary outcome was time to incision. Secondary outcomes included times to important milestones, percentage of tasks completed, and type of incision.The median (interquartile range) times from time zero to incision were 4:25 (3:59-4:50) and 7:53 (7:18-8:57) minutes in the labor room and operating room groups, respectively (P=.004). Fifty-seven percent of labor room teams and 14% of operating room teams achieved delivery within 5 minutes. Contacting the neonatal team, placing the defibrillator, resuming compressions after analysis, and endotracheal intubation all occurred more rapidly in the labor room group.Perimortem cesarean delivery performed in the labor room was significantly faster than perimortem cesarean delivery performed after moving to the operating room. Delivery within 5 minutes was challenging in either location despite optimal study conditions (eg, the manikin was light and easily moved; teams knew the scenario mandated perimortem cesarean delivery and were aware of being timed). Our findings imply that perimortem cesarean delivery during actual arrest would require more than 5 minutes and should be performed in the labor room rather than relocating to the operating room.

    View details for DOI 10.1097/AOG.0b013e3182319a08

    View details for Web of Science ID 000296292600017

    View details for PubMedID 22015877

  • Deficits in the provision of cardiopulmonary resuscitation during simulated obstetric crises AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY Lipman, S. S., Daniels, K. I., Carvalho, B., Arafeh, J., Harney, K., Puck, A., Cohen, S. E., Druzin, M. 2010; 203 (2)

    Abstract

    Previous work suggests the potential for suboptimal cardiopulmonary resuscitation (CPR) in the parturient but did not directly assess actual performance.We evaluated 18 videotaped simulations of maternal amniotic fluid embolus and resultant cardiac arrest. A checklist containing 10 current American Heart Association recommendations for advanced cardiac life support (ACLS) in obstetric patients was utilized. We evaluated which tasks were completed correctly and the time required to perform key actions.Proper compressions were delivered by our teams 56% of the time and ventilations 50% of the time. Critical interventions such as left uterine displacement and placing a firm back support prior to compressions were frequently neglected (in 44% and 22% of cases, respectively). The mean +/- SD overall composite score for the tasks was 45 +/- 12% (range, 20-60%). The neonatal team was called in a median (interquartile range) of 1:42 (0:44-2:18) minutes:seconds; 15 of 18 (83%) teams called only after the patient was completely unresponsive. Fifty percent of teams did not provide basic information to the neonatal teams as required by neonatal resuscitation provider guidelines.Multiple deficits were noted in the provision of CPR to parturients during simulated arrests, despite current ACLS certification for all participants. Current requirements for ACLS certification and training for obstetric staff may require revision.

    View details for DOI 10.1016/j.ajog.2010.02.022

    View details for Web of Science ID 000280234500037

    View details for PubMedID 20417476

  • 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

    Abstract

    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

  • Hetastarch co-loading is as effective as pre-loading for the prevention of hypotension following spinal anesthesia for cesarean delivery INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Mercier, F. J., Riley, E. T., Brummel, C., Cohen, S. E. 2009; 18 (2): 150-155

    Abstract

    Pre-loading with hetastarch decreases the incidence and severity of hypotension after spinal anesthesia for cesarean delivery. However, pharmacokinetic studies with crystalloid predict that fluid loading should be more efficacious if rapidly administered immediately after induction of spinal anesthesia. The aim of this study was to compare pre- and co-loading of hetastarch for the prevention of hypotension following spinal anesthesia for cesarean delivery.Forty-six healthy term parturients scheduled for cesarean delivery were randomized to receive 500 mL of 6% hetastarch intravenously, either slowly before spinal anesthesia (pre-loading) or as quickly as possible immediately after spinal anesthesia (co-loading). Systolic blood pressure was maintained at or above 90% of baseline with intravenous vasopressor boluses (ephedrine 5mg/mL+phenylephrine 25 microg/mL). The primary outcome was the volume of vasopressor mix required. Secondary outcomes included blood pressure and heart rate changes, time to first vasopressor use, nausea or vomiting, and neonatal outcomes (umbilical artery and vein pH, Apgar scores).The pre-loading group used 3.5+/-2 mL (mean+/-SD) of vasopressor mixture compared with 3.2+/-3 mL in the co-loading group (P=0.6). There were no differences in any important maternal hemodynamic or neonatal outcome values between the two study groups.Hetastarch co-loading is as effective as pre-loading for the prevention of hypotension after spinal anesthesia for cesarean delivery. Surgery need not be delayed to allow a predetermined pre-load to be administered before induction of spinal anesthesia.

    View details for DOI 10.1016/j.ijoa.2008.12.006

    View details for Web of Science ID 000265542200009

    View details for PubMedID 19223168

  • Airway management in Nager Syndrome LARYNGOSCOPE Ho, A. S., Aleshi, P., Cohen, S. E., Koltai, P. J., Cheng, A. G. 2009; 119: S179-S179

    View details for DOI 10.1002/lary.20468

    View details for Web of Science ID 000207862500179

  • Airway management in Nager Syndrome INTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGOLOGY Ho, A. S., Aleshi, P., Cohen, S. E., Koltai, P. J., Cheng, A. G. 2008; 72 (12): 1885-1888

    Abstract

    Nager acrofacial dysostosis is a rare congenital syndrome characterized by malformed mandibulofacial structures and pre-axial upper limbs. Trismus and glossoptosis from mandibular abnormalities predisposes infants to life-threatening respiratory distress. A case of a Nager Syndrome mother delivering a similarly afflicted fetus is presented, with approaches to maintaining both tenuous airways described. Distinguishing this condition from similar syndromes is critical for care and prognosis.

    View details for DOI 10.1016/j.ijporl.2008.09.007

    View details for Web of Science ID 000261543000021

    View details for PubMedID 18947886

  • Assessment of knowledge regarding cardiopulmonary resuscitation of pregnant women INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Cohen, S. E., Andes, L. C., Carvalho, B. 2008; 17 (1): 20-25

    Abstract

    The 2000-2002 triennial UK Report on Confidential Enquiries into Maternal Deaths concluded that over 50% of maternal deaths involved substandard care and that many could have been prevented. Catastrophic events leading to cardio-respiratory arrest may necessitate the resuscitation of pregnant women in various hospital locations. This study was designed to evaluate knowledge about resuscitation of parturients among anesthesiologists, obstetricians and emergency physicians.A 12-question survey was distributed anonymously to residents and faculty in the anesthesia (ANES), obstetrics (OB), and emergency medicine (EM) departments at Stanford University Medical Center/Lucile Packard Children's Hospital, Stanford, California. Questions were designed to elicit knowledge deficiencies in four critical areas: need for left uterine displacement (LUD), advanced cardiac life support algorithms (ACLS), physiologic changes of pregnancy (PHYS), and the recommendation to perform cesarean delivery in parturients (>20 weeks gestation) after 4-5 min of unsuccessful resuscitation for cardiac arrest (5CD).In total, 74/75 physicians (43% ANES, 37% OB, and 20% EM) completed the test. ANES scored highest in overall test scores, and in knowledge of PHYS (P<0.05). Scores for LUD and 5CD were similar among groups, but 25-40% of these questions were answered incorrectly. In the ACLS category, the EM group scored highest (93%).We conclude that knowledge of important basic concepts, including the need for LUD and the potential benefit of early cesarean delivery during cardiac arrest, is inadequate among all three specialties. All three departments should provide ACLS physician training with emphasis on the special considerations for parturients.

    View details for DOI 10.1016/j.ijoa.2007.10.002

    View details for Web of Science ID 000253167900005

    View details for PubMedID 18162200

  • Local infiltration of epinephrine-containing lidocaine with bicarbonate reduces superficial bleeding and pain during labor epidural catheter insertion: a randomized trial INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Fuller, A., Brummel, C., Cohen, S. E. 2007; 16 (2): 116-121

    Abstract

    Superficial bleeding after labor epidural catheter placement is a common phenomenon. In addition to delaying securing the epidural catheter, it may loosen the adhesive catheter dressing. The primary aim of this study was to determine whether skin infiltration with epinephrine-containing rather than plain lidocaine reduces superficial bleeding after catheter placement. Secondary objectives were to determine whether adding epinephrine and/or sodium bicarbonate affected infiltration pain.After institutional review board approval and informed consent, 80 healthy women receiving epidural analgesia during labor were randomly assigned in a double-blind manner to four local anesthetic mixtures (n=20 in each group): group L: lidocaine 1.5%, group LB: lidocaine 1.5% with 8.4% sodium bicarbonate, group LE: lidocaine 1.5% with epinephrine 1:200000, and group LEB: lidocaine 1.5% with epinephrine 1:200000 and 8.4% sodium bicarbonate. Clinical endpoints included the amount of superficial bleeding at the catheter site, pain during local anesthetic infiltration and epidural catheter movement during labor.Demographic data were similar among the groups. The addition of epinephrine to lidocaine significantly reduced superficial bleeding. Solutions containing epinephrine were well tolerated and caused no cardiovascular disturbances. The addition of epinephrine did not increase pain, while bicarbonate reduced it [verbal score (scale 0-10) 3.6+/-2.2 vs. 2.6+/-1.8; P=0.04]. There were no differences in epidural catheter movement among the groups; no catheters became displaced during labor.Local infiltration of epinephrine-containing lidocaine before epidural catheter insertion reduces superficial bleeding and the addition of bicarbonate decreases pain during skin infiltration.

    View details for DOI 10.1016/j.ijoa.2006.09.006

    View details for Web of Science ID 000245838800004

    View details for PubMedID 17276670

  • Valdecoxib for postoperative pain management after cesarean delivery: A randomized, double-blind, placebo-controlled study ANESTHESIA AND ANALGESIA Carvalho, B., Chu, L., Fuller, A., Cohen, S. E., Riley, E. T. 2006; 103 (3): 664-670

    Abstract

    Although nonsteroidal antiinflammatory drugs (NSAIDs) improve postoperative pain relief after cesarean delivery, they carry potential side effects (e.g., bleeding). Perioperative cyclooxygenase (COX)-2 inhibitors show similar analgesic efficacy to nonsteroidal antiinflammatory drugs in many surgical models but have not been studied after cesarean delivery. We designed this randomized double-blind study to determine the analgesic efficacy and opioid-sparing effects of valdecoxib after cesarean delivery. Healthy patients undergoing elective cesarean delivery under spinal anesthesia were randomized to receive oral valdecoxib 20 mg or placebo every 12 h for 72 h postoperatively. As a result of cyclooxygenase-2 inhibitors safety concerns that became apparent during this study, the study was terminated early after evaluating 48 patients. We found no differences in total analgesic consumption between the valdecoxib and placebo groups (121 +/- 70 versus 143 +/- 77 morphine mg-equivalents, respectively; P = 0.26). Pain at rest and during activity were similar between the groups despite adequate post hoc power to have detected a clinically significant difference. There were also no differences in IV morphine requirements, time to first analgesic request, patient satisfaction, side effects, breast-feeding success, or functional activity. Postoperative pain was generally well controlled. Adding valdecoxib after cesarean delivery under spinal anesthesia with intrathecal morphine is not supported at this time.

    View details for DOI 10.1213/01.ane.0000229702.42426.a6

    View details for Web of Science ID 000240049800025

    View details for PubMedID 16931678

  • A survey of labor patient-controlled epidural anesthesia practice in California hospitals INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Wang, P., Cohen, S. E. 2006; 15 (3): 217-222

    Abstract

    Patient-controlled epidural analgesia (PCEA) offers many advantages over continuous epidural infusions for labor analgesia including fewer physician interventions, improved analgesia and satisfaction, and reduced local anesthetic doses. However, anesthesiologists have been slow to adopt this technique, first described in 1988. No previous studies have evaluated specific labor patient-controlled epidural analgesia practices in the United States. The aim of this study was to determine labor epidural and patient-controlled epidural analgesia practices among California hospitals.Following institutional review board exemption approval, an online survey was created using freeonlinesurveys.com. An anonymous survey was sent via e-mail to 230 California Society of Anesthesiologists' members chosen at random to represent their hospitals' labor analgesia practices.We received 133 replies from the 230 survey requests sent, a 58% response rate. The median labor epidural rate among the hospitals involved was 65% (range 0-95%). Overall, only 25% of California hospitals use patient-controlled epidural analgesia for analgesia in labor, with greater use among hospitals with dedicated obstetric anesthesia coverage and larger numbers of deliveries. Reasons given for not using patient-controlled epidural analgesia include cost, clinician preference, safety concerns and the inconvenience of change.Despite the potential advantages of patient-controlled epidural analgesia over continuous epidural infusions for labor analgesia, patient-controlled epidural analgesia has not been widely adopted in California hospitals. Education regarding this technique is needed to encourage its increased use.

    View details for DOI 10.1016/j.ijoa.2006.03.006

    View details for Web of Science ID 000239166100007

    View details for PubMedID 16798447

  • Patient preferences for anesthesia outcomes associated with Cesarean delivery ANESTHESIA AND ANALGESIA Carvalho, B., Cohen, S. E., Lipman, S. S., Fuller, A., Mathusamy, A. D., Macario, A. 2005; 101 (4): 1182-1187

    Abstract

    When deciding on neuraxial medication (e.g., spinal opioids) for cesarean delivery (CS) under regional anesthesia, anesthesiologists make treatment decisions that "trade off" relieving pain with the potential for increased risk of side effects. No previous studies have examined obstetric patients' anesthesia preferences. Researchers administered 100 written surveys to pregnant women attending our institutions' expectant parent class. We determined patients' preferences for importance of specific intraoperative and postoperative anesthesia outcomes using priority ranking and relative value scales. We also explored patients' fears, concerns, and tolerance regarding CS and analgesics. Eighty-two of 100 surveys were returned and analyzed. Pain during and after CS was the greatest concern followed by vomiting, nausea, cramping, pruritus, and shivering. Ranking and relative value scores were closely correlated (R2 = 0.7). Patients would tolerate a visual analog pain score (0-100 mm) of 56 +/- 22 before exposing their baby to the potential effects of analgesics they receive. In contrast to previous general surgical population surveys that found nausea and vomiting as primary concerns, we found pain during and after CS as parturients' most important concern. Common side effects such as pruritus and shivering caused only moderate concern. This information should be used to guide anesthetic choices, e.g., inclusion of spinal opioids given in adequate doses.Medical care can be improved by incorporating patients' preferences into medical decision making. We surveyed obstetric patients to determine their preferences regarding potential cesarean delivery anesthesia outcomes. Unlike general surgical patients who rate nausea and vomiting highest, parturients considered pain during and after cesarean delivery the most important concern.

    View details for DOI 10.1213/01.ane.0000167774.36833.99

    View details for Web of Science ID 000232115400045

    View details for PubMedID 16192541

  • The ED50 and ED95 of intrathecal isobaric bupivacaine with opioids for cesarean delivery ANESTHESIOLOGY Carvalho, B., Durbin, M., Drover, D. R., Cohen, S. E., Ginosar, Y., Riley, E. T. 2005; 103 (3): 606-612

    Abstract

    The ideal intrathecal isobaric bupivacaine dose for cesarean delivery anesthesia is uncertain. While small doses (5-9 mg) of bupivacaine may reduce side effects such as hypotension, they potentially increase spinal anesthetic failures. This study determined the ED50 and ED95 of intrathecal isobaric bupivacaine (with adjuvant opioids) for cesarean delivery.After institutional review board approval and written informed consent were obtained, 48 parturients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were enrolled in this double-blind, randomized, dose-ranging study. Patients received a 5-, 6-, 7-, 8-, 9-, 10-, 11-, or 12-mg intrathecal isobaric bupivacaine dose with 10 microg fentanyl and 200 microg morphine. Overall anesthetic success was recorded when no intraoperative epidural supplement was required during the cesarean delivery. ED50 and ED95 values for overall anesthetic success were determined using a logistic regression model.ED50 and ED95 values for overall anesthetic success were 7.25 and 13.0 mg, respectively. No advantages for low doses could be demonstrated with regard to hypotension, nausea, vomiting, pruritus, or maternal satisfaction, although this study was underpowered to detect significant differences in secondary outcome variables.The ED50 and ED95 values (7.25 and 13.0 mg, respectively) for intrathecal isobaric bupivacaine in this circumstance are similar to values the authors determined recently for hyperbaric bupivacaine using similar methodology. These ED50 and ED95 values are significantly higher than those advocated in previous reports in which success was claimed using lower intrathecal bupivacaine doses. The current study used stricter criteria to define "successful" anesthesia and support the use of larger bupivacaine doses to ensure adequate patient comfort.

    View details for Web of Science ID 000231574300023

    View details for PubMedID 16129987

  • "Ultra-light" patient-controlled epidural analgesia during labor: effects of varying regimens on analgesia and physician workload INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Carvalho, B., Cohen, S. E., Giarrusso, K., Durbin, M., Riley, E. T., Lipman, S. 2005; 14 (3): 223-229

    Abstract

    Patient-controlled epidural analgesia (PCEA) offers many advantages over continuous epidural infusions for maintenance of labor analgesia. Some of these benefits may depend on the PCEA settings. This study evaluated several regimens for "ultra-light" (0.125%) PCEA with basal continuous infusion (CI) in labor with goals of minimizing physician interventions while providing good analgesia.Two hundred and twenty ASA I-II women receiving epidural analgesia during active labor (cervical dilation <5 cm) were randomly assigned in a double-blind manner to four treatment groups (n=30 in each). Analgesia was maintained with a PCEA/CI pump using bupivacaine 0.0625% + sufentanil 0.35 microg/mL. PCEA settings were: group A: CI 10 mL/h, PCEA bolus 6 mL, 8-min lockout; group B: CI 10 mL/h, PCEA bolus 12 mL, 16-min lockout; group C: CI 15 mL/h, PCEA bolus 6 mL, 8-min lockout; group D: CI 15 mL/h, PCEA bolus 12 mL, 16-min lockout.In groups A, B, C and D, 76, 77, 75 and 85% of parturients respectively, required no physician rescue boluses. Pain scores were low and maternal satisfaction was high in all groups, with minimal differences among them. Spontaneous vaginal delivery occurred in 78% of patients overall, instrumental (forceps or vacuum) delivery in 10% and cesarean section in 12%.These ultra-light PCEA regimens provided excellent analgesia with minimal physician workload and a high spontaneous delivery rate. Use of moderate to high-volume, ultra-light PCEA/CI techniques should facilitate provision of labor analgesia in busy obstetric units.

    View details for DOI 10.1016/j.ijoa.2005.02.003

    View details for Web of Science ID 000230915700008

    View details for PubMedID 15935646

  • Single-dose, sustained-release epidural morphine in the management of postoperative pain after elective Cesarean delivery: Results of a multicenter randomized controlled study ANESTHESIA AND ANALGESIA Carvalho, B., Riley, E., Cohen, S. E., Gambling, D., PALMER, C., Huffnagle, H. J., Polley, L., Muir, H., Segal, S., Lihou, C., Manvelian, G. 2005; 100 (4): 1150-1158

    Abstract

    In this multicenter, randomized, controlled study, we compared the analgesic efficacy and safety profile of a new single-dose extended-release epidural morphine (EREM) formulation (DepoDur) with that of epidural morphine sulfate for the management of postoperative pain for up to 48 h after elective cesarean delivery. ASA physical status I or II parturients (n = 75) were anesthetized with a combined spinal/epidural technique. Parturients received intrathecal bupivacaine 12-15 mg and fentanyl 10 mug for spinal anesthesia and a single epidural injection of either 5 mg of standard (conventional preservative-free) morphine or 5, 10, or 15 mg of extended-release morphine after cord clamping for postoperative pain control. Single-dose EREM 10 and 15 mg groups significantly decreased total supplemental opioid medication use and improved functional ability scores for 48 h after surgery compared with those receiving 5 mg of standard morphine. Visual analog scale pain scores at rest and with activity at 24 to 48 h after dosing were significantly better in the 10- and 15-mg single-dose EREM groups versus the standard morphine group. There were no significant differences between the two 5 mg (single-dose EREM and standard morphine) groups. Single-dose EREM was well tolerated, and most adverse events were mild to moderate in severity. Single-dose EREM is a potentially beneficial epidural analgesic for the management of post-cesarean delivery pain and has particular advantages over standard morphine for the period from 24 to 48 h after surgery.

    View details for DOI 10.1213/01.ANE.0000149544.58230.FF

    View details for Web of Science ID 000227792400040

    View details for PubMedID 15781537

  • Randomized comparison of intravenous nitroglycerin and subcutaneous terbutaline for external cephalic version under tocolysis AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY El-Sayed, Y. Y., Pullen, K., Riley, E. T., Lyell, D., Druzin, M. L., Cohen, S. E., Chitkara, U. 2004; 191 (6): 2051-2055

    Abstract

    The purpose of this study was to compare the efficacy and safety of intravenous nitroglycerin with that of subcutaneous terbutaline as a tocolytic agent for external cephalic version at term.We performed a prospective randomized trial. Patients between 37 and 42 weeks of gestation were assigned randomly to receive either 200 microg of intravenous nitroglycerin therapy or 0.25 mg of subcutaneous terbutaline therapy for tocolysis during external cephalic version. The rate of successful external cephalic version and side effects were compared between groups.Of 59 randomly assigned patients, 30 patients received intravenous nitroglycerin, and 29 patients received subcutaneous terbutaline. The overall success rate of external cephalic version in the study was 39%. The rate of successful external cephalic version was significantly higher in the terbutaline group (55% vs 23%; P = .01). The incidence of palpitations was significantly higher in patients who received terbutaline therapy (17.2% vs 0%; P = .02), as was the mean maternal heart rate at multiple time periods.Compared with intravenous nitroglycerin, subcutaneous terbutaline was associated with a significantly higher rate of successful external cephalic version at term.

    View details for DOI 10.1016/j.ajog.2004.04.040

    View details for Web of Science ID 000225925800030

    View details for PubMedID 15592291

  • Correction of intraoperative coagulopathy in a patient with neurofibromatosis type I with intravenous desmopressin (DDAVP) INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Lighthall, G. K., Morgan, C., Cohen, S. E. 2004; 13 (3): 174-177

    Abstract

    A patient with the genetic condition neurofibromatosis type I and no known coagulopathy undergoing cesarean delivery, had diffuse uterine and surgical site bleeding that was not correctable by oxytocin, methylergonovine and PGF2 alpha. Despite good uterine tone, hemorrhage continued from the uterus and the surrounding tissues, persisting even after surgical ligation of the uterine arteries. With no change in her condition, which was behaving clinically as a coagulopathy, an infusion of desmopressin acetate (DDAVP) was begun. The patient's bleeding promptly resolved shortly after infusion of this agent. A review of relevant literature suggests that platelet reactivity of patients with neurofibromatosis type 1 is attenuated in some in vitro conditions. Thus, there may be some theoretical basis for using DDAVP in patients with neurofibromatosis type 1 who have bleeding problems with no other known source, such as in the case presented here.

    View details for DOI 10.1016/j.ijoa.2004.01.008

    View details for Web of Science ID 000222738700008

    View details for PubMedID 15321397

  • ED50 and ED95 of intrathecal hyperbaric bupivacaine coadministered with opioids for cesarean delivery ANESTHESIOLOGY Ginosar, Y., Mirikatani, E., Drover, D. R., Cohen, S. E., Riley, E. T. 2004; 100 (3): 676-682

    Abstract

    Successful cesarean delivery anesthesia has been reported with use of small doses (5-9 mg) of intrathecal bupivacaine coadministered with opioids. This double-blind, randomized, dose-ranging study determined the ED50 and ED95 of intrathecal bupivacaine (with adjuvant opioids) for cesarean delivery anesthesia.Forty-two parturients undergoing elective cesarean delivery with use of combined spinal-epidural anesthesia received intrathecal hyperbaric bupivacaine in doses of 6, 7, 8, 9, 10, 11, or 12 mg in equal volumes with an added 10 microg intrathecal fentanyl and 200 microg intrathecal morphine. Sensory levels (pinprick) were evaluated every 2 min until a T6 level was achieved. The dose was a success(induction) if a bilateral T6 block occurred in 10 min; otherwise, it was a failure(induction). In addition to being a success(induction), the dose was a success(operation) if no intraoperative epidural supplement was required; otherwise, it was a failure(operation). ED50 and ED95 for both success(induction) and success(operation) were determined with use of a logistic regression model.ED50 for success(induction) and success(operation) were 6.7 and 7.6 mg, respectively, whereas the ED95 for success(induction) and success(operation) were 11.0 and 11.2 mg. Speed of onset correlated inversely with dose. Although no clear advantage for low doses could be demonstrated (hypotension, nausea, vomiting, pruritus, or maternal satisfaction), this study was underpowered to detect significance in these variables.The ED95 of intrathecal bupivacaine under the conditions of this study is considerably in excess of the low doses proposed for cesarean delivery in some recent publications. When doses of intrathecal bupivacaine less than the ED95, particularly near the ED50, are used, the doses should be administered as part of a catheter-based technique.

    View details for Web of Science ID 000189251700030

    View details for PubMedID 15108985

  • The site of action of epidural fentanyl infusions in the presence of local anesthetics: A minimum local analgesic concentration infusion study in nulliparous labor ANESTHESIA AND ANALGESIA Ginosar, Y., Columb, M. O., Cohen, S. E., Mirikatani, E., Tingle, M. S., Ratner, E. F., Angst, M. S., Riley, E. T. 2003; 97 (5): 1439-1445

    Abstract

    We have previously demonstrated that continuous epidural infusions of fentanyl without local anesthetics elicit analgesia by a systemic mechanism. In this study, we examined the hypothesis that, in the presence of epidural bupivacaine, continuous infusions of epidural fentanyl elicit analgesia by a spinal mechanism. Forty-eight nulliparous women in active labor participated in this prospective, randomized, double-blinded study. Women received lumbar epidural analgesia with 20-30 mL bupivacaine 0.125% until pain free. Subjects were then randomized to either IV or epidural (EPI) fentanyl infusion groups. Each infusion delivered fentanyl 30 microg/h. All women received an epidural infusion of bupivacaine at a rate of 20 mL/h, the concentration of which was determined by the response of the previous woman in the same group to the analgesic regimen used. Unlike previous studies that assessed the minimum local analgesic concentration (MLAC) for bolus administration at the initiation of analgesia, this study assessed MLAC(infusion) for the maintenance of analgesia throughout the first stage of labor. MLAC(infusion) was determined using the up-down sequential analysis described by Dixon and Massey. The MLAC(infusion) of epidural bupivacaine was 0.063% (95% confidence interval, 0.058-0.068) and 0.019% (95% confidence interval, 0.000-0.038) in the IV and EPI groups respectively. A continuous infusion of fentanyl was more than three times as potent when administered by the epidural than by the IV route. This marked increase in potency for the epidural route is highly suggestive for a predominantly spinal mechanism of action for infused epidural fentanyl under the conditions of this study.This study determined the median effective concentration for epidural infusions of bupivacaine during labor analgesia. Coadministered epidural fentanyl infusions were more than three times more potent than IV fentanyl infusions, suggesting a predominantly spinal mechanism of opioid action under these study conditions.

    View details for DOI 10.1213/01.ANE.0000081792.84877.A2

    View details for Web of Science ID 000186143600038

    View details for PubMedID 14570662

  • A comparison of the 24-gauge Sprotte (R) and Gertie Marx (R) spinal needles for combined spinal-epidural analgesia during labor ANESTHESIOLOGY Riley, E. T., Hamilton, C. L., Ratner, E. F., Cohen, S. E. 2002; 97 (3): 574-577

    Abstract

    Prior experience with the combined spinal-epidural technique (CSE) for labor analgesia demonstrated a high (up to 14%) failure rate because of failure to obtain cerebrospinal fluid (CSF) or lack of response to appropriate doses of intrathecal sufentanil. The current study was designed to test whether a longer needle with a shorter side port (Gertie Marx needle; 127 mm long) would eliminate failures to obtain CSF compared with the needle we had used previously (Sprotte needle; 120 mm long).Seventy-three parturients were randomly assigned to have a CSE performed with one of these two needles. After identifying the epidural space with an 18-gauge Touhy needle at the L2-L3 or L3-L4 interspace, the spinal needle was introduced through the Touhy needle until penetration of the dura was felt or until the needle was maximally inserted. If no CSF was obtained, the alternate needle was tried. After obtaining CSF, 10 microg sufentanil diluted in 1.8 ml saline was injected. Verbal pain scores (0-10) were obtained every 5 min for 30 min.Failure to obtain CSF occurred six times in the Sprotte group compared with none in the Gertie Marx group (P < 0.05). In all six failures in the Sprotte group, the Gertie Marx needle subsequently proved successful in obtaining CSF. There were no differences in pain scores between the groups.The extra length of the 127-mm Gertie Marx needle resulted in a higher success rate for obtaining CSF when used in the CSE technique. Side port design was not a factor influencing success in this clinical setting.

    View details for Web of Science ID 000177766100008

    View details for PubMedID 12218522

  • Mask induction with sevoflurane in a parturient with severe tracheal stenosis ANESTHESIOLOGY Ratner, E. F., Cohen, S. E., El Sayed, Y., Druzin, M. 2001; 95 (2): 553-555

    View details for Web of Science ID 000170237800040

    View details for PubMedID 11506134

  • Labor epidural analgesia: back to the dark ages or a potential win-win situation INTERNATIONAL JOURNAL OF OBSTETRIC ANESTHESIA Cohen, S. E. 1999; 8 (4): 223-225

    View details for Web of Science ID 000086029800002

    View details for PubMedID 15321114

  • Statistical analysis of total labor pain using the visual analog scale and application to studies of analgesic effectiveness during childbirth ANESTHESIA AND ANALGESIA Cohen, S. E. 1999; 88 (5): 1193-1194

    View details for Web of Science ID 000080063000057

    View details for PubMedID 10320205

  • Randomized comparison of intravenous nitroglycerin and magnesium sulfate for treatment of preterm labor OBSTETRICS AND GYNECOLOGY El-Sayed, Y. Y., Riley, E. T., Holbrook, R. H., Cohen, S. E., Chitkara, U., Druzin, M. L. 1999; 93 (1): 79-83

    Abstract

    To compare the safety and efficacy of high-dose intravenous (IV) nitroglycerin with those of IV magnesium sulfate for acute tocolysis of preterm labor.Thirty-one women with preterm labor before 35 weeks' gestation were assigned randomly to IV magnesium sulfate or IV nitroglycerin for tocolysis. Preterm labor was defined as the occurrence of at least two contractions in 10 minutes, with cervical change or ruptured membranes. Acute tocolysis was defined as tocolysis for up to 48 hours. Magnesium sulfate was administered as a 4-g bolus, then at a rate of 2-4 g/h. Nitroglycerin was administered as a 100-microg bolus, then at a rate of 1- to 10-microg/kg/min. The primary outcome measure was achievement of at least 12 hours of successful tocolysis.Thirty patients were available for analysis. There were no significant differences in gestational age, cervical dilation, or incidence of ruptured membranes between groups at the initiation of tocolysis. Successful tocolysis was achieved in six of 16 patients receiving nitroglycerin, compared with 11 of 14 receiving magnesium sulfate (37.5 versus 78.6%, P = .033). Tocolytic failures (nitroglycerin versus magnesium sulfate) were due to persistent contractions with cervical change or rupture of previously intact membranes (five of 16 versus two of 14), persistent hypotension (four of 16 versus none of 14), and other severe side effects (one of 16 versus one of 14). Maternal hemodynamic alterations were more pronounced in patients who received nitroglycerin, and 25% of patients assigned to nitroglycerin treatment had hypotension requiring discontinuation of therapy.Tocolytic failures were more common with nitroglycerin than with magnesium sulfate. The hemodynamic alterations noted in patients receiving nitroglycerin, including a 25% incidence of persistent hypotension, might limit the usefulness of IV nitroglycerin for the acute tocolysis of preterm labor.

    View details for Web of Science ID 000077885200017

    View details for PubMedID 9916961

  • Obstetric postanesthesia care unit stays - Reevaluation of discharge criteria after regional anesthesia ANESTHESIOLOGY Cohen, S. E., Hamilton, C. L., Riley, E. T., Walker, D. S., Macario, A., Halpern, J. W. 1998; 89 (6): 1559-1565

    Abstract

    Obstetric patients may have long postanesthesia care unit (OB-PACU) stays after surgery because of residual regional block or other conditions. This study evaluated whether modified discharge criteria might allow for earlier discharge without compromising patient safety.Data were prospectively collected for 6 months for all patients (N=358) who underwent cesarean section or tubal ligation and recovered in the OB-PACU. Regional anesthesia was used in 94% of patients. The duration of anesthesia and PACU stays, the presence and treatment of events in the PACU, and the regression of neural blockade were recorded. Discharge from the OB-PACU required a 60-min minimum stay, stable vital signs, adequate analgesia, and ability to flex the knees. After completion of prospective data collection, events that kept patients in the PACU after 60 min were reevaluated as to whether patients needed to stay in the PACU for medical reasons. "Needed to stay" events included bleeding, cardiorespiratory problems, sedation, dizziness, and pain. "Safe to leave" conditions included pruritus, nausea, and residual neural blockade. The cumulative duration of OB-PACU stays not clearly justifiable for medical reasons was calculated.Residual block and spinal opioid side effects accounted for the majority of "unnecessary" stays. Annually, 429 h of PACU time could have been saved using the revised criteria. Complications did not develop subsequently in any patient deemed "safe to leave."In many obstetric patients, the duration of PACU stays could safely be shortened by continuing observation in a lower-acuity setting. This may result in greater flexibility and more efficient use of nursing personnel.

    View details for Web of Science ID 000077376100035

    View details for PubMedID 9856733

  • Intrathecal sufentanil produces sensory changes without hypotension in male volunteers ANESTHESIOLOGY Riley, E. T., Hamilton, C. L., Cohen, S. E. 1998; 89 (1): 73-78

    Abstract

    Intrathecally administered sufentanil is frequently associated with hypotension and sensory changes in women undergoing labor. In this study, the authors examined whether intrathecally administered sufentanil has similar effects in pain-free individuals with low concentrations of progesterone (i.e., male volunteers).Ten male volunteers were randomly assigned to receive an intrathecal injection of either 10 microg sufentanil or saline in a double-blind fashion. Blood pressure, heart rate, oxyhemoglobin saturation, and temperatures from the body core and skin of the calf and ipsilateral great toe were recorded. Cold and pin prick sensation, motor block, and visual analogue scores for sedation, pruritus, and nausea also were assessed. Current perception thresholds using the Neurometer current perception threshold instrument (Neurotron, Inc., Baltimore, MD) were determined for three frequencies (2,000, 250, and 5 Hz, corresponding to stimulation of Abeta, Adelta, and C fibers, respectively) on the upper and lower extremities.Pruritus and sensory changes to pin prick and cold occurred in the sufentanil group but not the saline group. Neither group had a significant change in blood pressure, heart rate, oxyhemoglobin saturation, sedation, or core temperature. There was a clinically insignificant difference in the calf minus toe temperature index between the saline and sufentanil groups. There was a small increase in the current perception thresholds at 250 Hz in the sufentanil group.Intrathecally administered sufentanil did not affect blood pressure in male volunteers. The other effects of sufentanil, however, were similar to those observed in women undergoing labor. This suggests that the hypotension occurring in these women after intrathecally administered sufentanil is secondary to relief of pain, rather than to a sympathectomy.

    View details for Web of Science ID 000074710800012

    View details for PubMedID 9667296

  • Changes in the position of epidural catheters associated with patient movement ANESTHESIOLOGY Hamilton, C. L., Riley, E. T., Cohen, S. E. 1997; 86 (4): 778-784

    Abstract

    Epidural catheter movement has been noted with change of patient position and can result in inadequate anesthesia. This study was designed to measure movement and to develop a technique that minimizes catheter displacement.In 255 parturients requesting epidural anesthesia for labor or cesarean section, a multiorificed lumbar epidural catheter was inserted with the patient in the sitting flexed position. The distance to the epidural space, length of catheter inserted, and amount of catheter position change as the patient moved from the sitting flexed to sitting upright and then to the lateral decubitus position were measured before the catheter was secured to the skin. Adequacy of analgesia, the need for catheter manipulation, and whether the patient was considered obese were noted. Data were grouped according to body mass index (BMI): < 25, 25-30, and > 30 kg/m2.The groups did not differ with respect to the length of catheter initially inserted or changes in catheter position between initial taping and removal. The distance to the epidural space differed significantly among the groups, increasing with greater BMI. Catheters frequently appeared to be drawn inward with position change from the sitting flexed to lateral decubitus position, with the greatest change seen in patients with BMI > 30. Only nine catheters were associated with inadequate analgesia, four of which were replaced. No analgesic failures occurred in the BMI > 30 group. In patients judged by the anesthesiologist to be obese or to have an obese back, BMI was greater, and distance to the epidural space and the magnitude of catheter movement with position change were greater than in those who were not obese.Epidural catheters moved a clinically significant amount with reference to the skin in all BMI groups as patients changed position. If catheters had been secured to the skin before position change, many would have been pulled partially out of the epidural space. To minimize the risk of catheter displacement, particularly in obese patients, we recommend that multiorificed catheters be inserted at least 4 cm into the epidural space and that patients assume the sitting upright or lateral position before securing the catheter to the skin.

    View details for Web of Science ID A1997WT00800009

    View details for PubMedID 9105221

  • Strategies for labor pain relief--past, present and future. Acta anaesthesiologica Scandinavica. Supplementum Cohen, S. 1997; 110: 17-21

    View details for PubMedID 9248517

  • Intravenous nitroglycerin: a potent uterine relaxant for emergency obstetric procedures. Review of literature and report of three cases. International journal of obstetric anesthesia Riley, E. T., Flanagan, B., Cohen, S. E., Chitkarat, U. 1996; 5 (4): 264-268

    View details for PubMedID 15321327

  • Ketorolac and spinal morphine for postcesarean analgesia. International journal of obstetric anesthesia Cohen, S. E., Desai, J. B., Ratner, E. F., Riley, E. T., Halpern, J. 1996; 5 (1): 14-18

    Abstract

    This study was designed to compare spinal morphine (SM), ketorolac (K), and a combination of the two drugs with respect to analgesic efficacy and side effects in postcesarean patients. Forty-eight parturients having bupivacaine spinal anesthesia for cesarean delivery randomly received in a double-blind manner either: SM: 0.1 mg or SM: 0.2 mg (but no K); SM: 0.1 mg plus K 60 mg intravenously (i.v.) one hour after spinal injection, and 30 mg i.v. every 6 h for three doses or i.v. K dosed as previously described (but no SM). Analgesia and side effects were evaluated during the first 20 h. Forty-eight women were studied. There were no significant differences in analgesia among the groups, although patients receiving SM: 0.1 mg tended to have less satisfactory intraoperative analgesia. Pruritus was common in all patients receiving SM whereas patients who received K had the lowest overall scores for severity of side effects. No serious complications occurred and all groups expressed similarly high satisfaction at the 24 h visit. We conclude that there is no advantage to combining SM and K, and that K provides satisfactory postcesarean analgesia with few side effects.

    View details for PubMedID 15321377

  • HIGH SENSORY BLOCK AFTER INTRATHECAL SUFENTANIL FOR LABOR ANALGESIA ANESTHESIOLOGY Hamilton, C. L., Cohen, S. E. 1995; 83 (5): 1118-1121

    View details for Web of Science ID A1995TD72300029

    View details for PubMedID 7486165

  • PREVENTION OF HYPOTENSION AFTER SPINAL-ANESTHESIA FOR CESAREAN-SECTION - 6 PERCENT HETASTARCH VERSUS LACTATED RINGERS SOLUTION ANESTHESIA AND ANALGESIA Riley, E. T., Cohen, S. E., Rubenstein, A. J., Flanagan, B. 1995; 81 (4): 838-842

    Abstract

    This study was designed to determine whether preoperative administration of 6% hetastarch decreases the incidence and severity of hypotension after spinal anesthesia for cesarean section. Forty nonlaboring ASA class I and II women having nonurgent cesarean sections were randomized to receive either 500 mL of 6% hetastarch plus 1 L lactated Ringer's solution (LR) (n = 20), or 2 L of LR (n = 20) prior to induction of spinal anesthesia. Hypotension occurred in 45% of patients who received hetastarch vs 85% of those who received only LR (P < 0.05), and minimum systolic blood pressure was lower in the LR group than in the hetastarch group (85 +/- 12 vs 93 +/- 12 mm Hg [mean +/- SD]; P < 0.05). In addition, the LR group had a higher maximum heart rate (115 +/- 17 vs 104 +/- 16 bpm), a shorter mean time to hypotension (7 +/- 4 vs 10 +/- 7 min), and required more 5-mg doses of ephedrine for treatment of hypotension (0 vs 2 [median]; P < 0.05) than the hetastarch group. Neonatal outcome, as determined by Apgar scores and cord blood gas analyses, was good and similar in both groups. We conclude that 6% hetastarch plus LR is more effective than LR alone and that its routine use before spinal anesthesia for cesarean section should be considered.

    View details for Web of Science ID A1995RX47700031

    View details for PubMedID 7574020

  • PLACENTAL-TRANSFER AND NEONATAL EFFECTS OF EPIDURAL SUFENTANIL AND FENTANYL ADMINISTERED WITH BUPIVACAINE DURING LABOR ANESTHESIOLOGY LOFTUS, J. R., Hill, H., Cohen, S. E. 1995; 83 (2): 300-308

    Abstract

    This randomized double-blind investigation was designed to study the placental transfer and neonatal effects of epidural sufentanil and fentanyl infused with bupivacaine for labor analgesia.Healthy parturient women (n = 36) received epidural bupivacaine alone (group B) or with fentanyl (group B-F) or sufentanil (group B-S). Group B received a 12-ml bolus of 0.25% bupivacaine followed by a 10 ml/h infusion of 0.125% bupivacaine. Groups B-F and B-S received a 12-ml bolus of 0.125% bupivacaine with 75 micrograms fentanyl or 15 micrograms sufentanil, respectively, followed by 10 ml/h of 0.125% bupivacaine with fentanyl 1.5 micrograms/ml or sufentanil 0.25 micrograms/ml. Maternal venous (MV) and umbilical arterial (UA) and umbilical venous (UV) bupivacaine and opioid plasma concentrations were determined. Neonatal assessment included Apgar scores, umbilical cord blood gas analyses, and neurobehavioral testing at delivery and at 2 and 24 h of life using the Neurologic and Adaptive Capacity Score (NACS).The mean total dose of fentanyl was 136.6 +/- 13.1 micrograms (SEM), and of sufentanil, 23.8 +/- 1.8 micrograms. Although administered in a ratio of 5.7:1, fentanyl and sufentanil MV plasma concentrations were in the ratio of 27:1. UV/MV ratios were 0.37 for fentanyl and 0.81 for sufentanil. Fentanyl was detected in most UA samples, whereas sufentanil was present in only one sample. Neonatal condition was good and generally similar in all groups, with the exception of a lower NACS at 24 h in group B-F.Although the degree of placental transfer of sufentanil appeared greater than that of fentanyl, lower MV sufentanil concentrations resulted in less fetal exposure to sufentanil. The lower NACS at 24 h in group B-F may reflect the continued presence of fentanyl in the neonate.

    View details for Web of Science ID A1995RM71100011

    View details for PubMedID 7631952

  • SPINAL VERSUS EPIDURAL-ANESTHESIA FOR CESAREAN-SECTION - A COMPARISON OF TIME EFFICIENCY, COSTS, CHARGES, AND COMPLICATIONS ANESTHESIA AND ANALGESIA Riley, E. T., Cohen, S. E., Macario, A., Desai, J. B., Ratner, E. F. 1995; 80 (4): 709-712

    Abstract

    Spinal anesthesia recently has gained popularity for elective cesarean section. Our anesthesia service changed from epidural to spinal anesthesia for elective cesarean section in 1991. To evaluate the significance of this change in terms of time management, costs, charges, and complication rates, we retrospectively reviewed the charts of patients who had received epidural (n = 47) or spinal (n = 47) anesthesia for nonemergent cesarean section. Patients who received epidural anesthesia had significantly longer total operating room (OR) times than those who received spinal anesthesia (101 +/- 20 vs 83 +/- 16 min, [mean +/- SD] P < 0.001); this was caused by longer times spent in the OR until surgical incision (46 +/- 11 vs 29 +/- 6 min, P < 0.001). Length of time spent in the postanesthesia recovery unit was similar in both groups. Supplemental intraoperative intravenous (i.v.) analgesics and anxiolytics were required more often in the epidural group (38%) than in the spinal group (17%) (P < 0.05). Complications were noted in six patients with epidural anesthesia and none with spinal anesthesia (P < 0.05). Average per-patient charges were more for the epidural group than for the spinal group. Although direct cost differences between the groups were negligible, there were more substantial indirect costs differences. We conclude that spinal block may provide better and more cost effective anesthesia for uncomplicated, elective cesarean sections.

    View details for Web of Science ID A1995QP46200010

    View details for PubMedID 7893022

  • PARTURIENTS POSTURE DURING EPIDURAL PUNCTURE AFFECTS THE DISTANCE FROM SKIN TO EPIDURAL SPACE JOURNAL OF CLINICAL ANESTHESIA Hamza, J., Smida, M., Benhamou, D., Cohen, S. E. 1995; 7 (1): 1-4

    Abstract

    To assess the factors affecting the distance from skin to epidural space.Prospective observational study of consecutive cases over a 2-year period.Inpatient obstetric unit in a French university hospital.2,123 consecutive term parturients who received epidural anesthesia for cesarean section or epidural analgesia for labor and vaginal delivery.At the time of epidural puncture, the interspace used and the patient's posture (sitting or left lateral decubitus) were recorded, and the distance from the skin to the epidural space (DS-ES) was measured to the nearest 0.5 cm using a marked epidural needle.The relationship between patient factors [height, weight, body mass index (BMI; weight/height2), presence of scoliosis] and technical factors (interspace, patient's posture at puncture) versus DS-ES was investigated using multiple regression analysis. DS-ES correlated positively with the parturient's weight and BMI. In addition, DS-ES was significantly greater when epidural puncture was performed in the lateral position as compared with the sitting position.Both the patient's weight and position during epidural needle placement are important factors influencing DS-ES. A change from the sitting to the lateral position may increase DS-ES, causing catheter dislodgment and consequent inadequate analgesia. Clinical studies relating DS-ES to inadequate analgesia must take these factors into account.

    View details for Web of Science ID A1995QQ24600001

    View details for PubMedID 7772351

  • EPIDURAL ANALGESIA AND THE INCIDENCE OF CESAREAN-SECTION - TIME FOR A CLOSER LOOK ANESTHESIOLOGY Dewan, D. M., Cohen, S. E. 1994; 80 (6): 1189-1192

    View details for Web of Science ID A1994NR92600003

    View details for PubMedID 8010464

  • INTRATHECAL SUFENTANIL FOR LABOR ANALGESIA - SENSORY CHANGES, SIDE-EFFECTS, AND FETAL HEART-RATE CHANGES ANESTHESIA AND ANALGESIA Cohen, S. E., CHERRY, C. M., Holbrook, R. H., ELSAYED, Y. Y., Gibson, R. N., Jaffe, R. A. 1993; 77 (6): 1155-1160

    Abstract

    This study was designed to evaluate intrathecal (IT) sufentanil for labor analgesia with respect to sensory changes, side effects, and fetal heart rate (FHR) changes. In Phase I of the study, data regarding duration of analgesia and hemodynamic changes were obtained retrospectively from the labor and anesthetic records of 90 patients who had received IT sufentanil, 10 micrograms in 1 mL of saline, during active labor. In Phase II, an additional 18 parturients who received similar treatment were studied prospectively to document sensory, motor, and hemodynamic changes, as well as the incidence of side effects. In Phase I, analgesia occurred rapidly and lasted 124 +/- 68 min (SD); 19% of patients required no further analgesia before delivery. In Phase II, median time to onset of analgesia was 3 min (range 1-6 min) and mean duration of analgesia was 96 +/- 36 min. Decreased sensation to pinprick and cold occurred within 6 min extending from T4 to L4 (upper and lower median levels) in the majority of patients. All subjects requested additional analgesia within approximately 30 min of recession of sensory changes. Motor strength remained normal throughout. Hypotension (systolic blood pressure [BP] < or = 90 mm Hg or > 20% decrease in systolic BP) occurred in 14% and 11% of patients in Phase I and II, respectively. Perineal itching preceded analgesia in 95% of patients and all subjects experienced mild sedation. FHR changes occurred in 15% of cases but were not associated with adverse neonatal outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1993MK04800013

    View details for PubMedID 8250307

  • NALBUPHINE IS BETTER THAN NALOXONE FOR TREATMENT OF SIDE-EFFECTS AFTER EPIDURAL MORPHINE ANESTHESIA AND ANALGESIA Cohen, S. E., Ratner, E. F., KREITZMAN, T. R., ARCHER, J. H., MIGNANO, L. R. 1992; 75 (5): 747-752

    Abstract

    This study compared naloxone and nalbuphine when administered for treatment of side effects after epidural morphine, 5 mg, given for postcesarean analgesia. Patients requesting treatment for pruritus or nausea randomly received, in a double-blind fashion, up to three intravenous doses of either naloxone 0.2 mg (group 1; n = 20) or nalbuphine 5 mg (group 2; n = 20). The incidence of vomiting, the severity of nausea and pruritus, and the degree of sedation and pain were assessed before and 30 min after each dose. The first dose of nalbuphine decreased the incidence of vomiting (P < 0.005) and the severity of nausea and pruritus (P < 0.01), whereas naloxone caused no significant changes. Sedation scores increased after nalbuphine (P < 0.05) and remained unchanged after naloxone, whereas pain scores increased after naloxone (P < 0.01) and were unchanged after nalbuphine. Eighteen patients in group 1 and 12 in group 2 received a second dose, and 8 and 4 patients, respectively, a third dose. Other than decreased pruritus after the second dose with both drugs, no further changes occurred. We conclude that nalbuphine is superior to naloxone for the treatment of side effects after epidural morphine. However, persistent symptoms may require supplemental therapy, as repeated doses proved less effective than the initial dose.

    View details for Web of Science ID A1992JV69800016

    View details for PubMedID 1416128

  • RESPIRATORY EFFECTS OF EPIDURAL SUFENTANIL AFTER CESAREAN-SECTION ANESTHESIA AND ANALGESIA Cohen, S. E., Labaille, T., Benhamou, D., Levron, J. C. 1992; 74 (5): 677-682

    Abstract

    The ventilatory response to CO2 was measured to evaluate the degree of respiratory depression after epidural sufentanil. After cesarean section performed with bupivacaine epidural anesthesia, 14 patients received either 30 micrograms (n = 7) or 50 micrograms (n = 7) of epidural sufentanil. Respiratory measurements were made before and 15, 45, and 120 min after sufentanil injection. The presence and severity of sedation and other nonrespiratory side effects were evaluated throughout the study. Plasma sufentanil assays were performed on blood samples obtained at frequent intervals during the first 2 h. Although changes in resting ventilation did not occur, both sufentanil doses depressed the ventilatory response to CO2. After sufentanil 30 micrograms, the slope of the CO2 response curve decreased significantly at 45 and 120 min (control value, 2.33 +/- 0.3 L.min-1.mm Hg-1 [mean +/- SEM] vs 1.61 +/- 0.24 and 1.72 +/- 0.15, respectively, P less than 0.05). After sufentanil 50 micrograms, significant decreases occurred at 15 and 45 min (control value, 2.84 +/- 0.71 vs 1.81 +/- 0.48 and 1.48 +/- 0.31 L.min-1.mm Hg-1, respectively). The mean maximal decrease in the slope occurred at 45 min and was more pronounced after 50 micrograms (-42.3% +/- 7.4%) than after 30 micrograms (-27.4% +/- 9.9%). Analgesia was similar in both groups. Side effects, particularly sedation, were more severe with the 50-micrograms dose. We conclude that 30 micrograms of epidural sufentanil is preferable to the higher dose with regard to both respiratory and nonrespiratory side effects. Even with the lower dose, monitoring of ventilation is advisable for a minimum of 2 h.

    View details for Web of Science ID A1992HQ20800010

    View details for PubMedID 1533106

  • FETAL HEART-RATE AFTER EPIDURAL LIDOCAINE AND BUPIVACAINE FOR ELECTIVE CESAREAN-SECTION ANESTHESIOLOGY LOFTUS, J. R., Holbrook, R. H., Cohen, S. E. 1991; 75 (3): 406-412

    Abstract

    This prospective double-blind study was designed to determine whether the fetal heart rate (FHR) changes that have been reported after epidural administration of bupivacaine and lidocaine during labor are present when larger doses of these drugs are given during elective cesarean section. Prior to inserting an epidural catheter, FHR and maternal vital signs were monitored during a control period in 60 healthy term parturients. Patients were randomly assigned to receive either 0.5% bupivacaine with 0.1 mEq sodium bicarbonate added to each 20 ml (n = 30) or 2% lidocaine with 1:300,000 epinephrine (n = 30). A 3-ml test dose of the study solution was injected via the catheter and was followed by an additional 17 ml, in increments; additional doses were administered as necessary to obtain surgical anesthesia. FHR and maternal vital signs were monitored for at least 20 min and the characteristics of the anesthetic block noted. At delivery, neonatal status was evaluated, and maternal and cord blood samples were obtained for local anesthetic assays and neonatal blood gases. The groups were similar with respect to maternal characteristics, onset of surgical anesthesia, time to delivery, and uterine incision-delivery interval. Maternal blood pressure decreased from control values in both groups (P less than 0.05), but there was no difference between the groups in either the incidence of hypotension or ephedrine requirements. Analysis of FHR tracings by a perinatologist blinded to the study group revealed no changes after anesthesia and no significant differences between the groups at any time in basal FHR, short- or long-term variability, or the incidence of accelerations or decelerations.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1991GD69900005

    View details for PubMedID 1888047

  • VENTILATORY RESPONSE TO CARBON-DIOXIDE AFTER EPIDURAL CLONIDINE INJECTION ANESTHESIA AND ANALGESIA Penon, C., Ecoffey, C., Cohen, S. E. 1991; 72 (6): 761-764

    Abstract

    The authors studied the effects of epidural clonidine (300 micrograms) on circulation and ventilatory control in seven healthy unpremedicated subjects. After clonidine injection, arterial blood pressure decreased significantly in all subjects (range, 13%-25% for systolic blood pressure and 13%-32% for diastolic blood pressure). Heart rate decreased significantly by 10%-16% between 75 and 105 min after injection. The slope of the ventilatory response to CO2 decreased significantly from 2.06 +/- 0.70 (baseline) to 1.37 +/- 0.68, 1.25 +/- 0.65, and 1.33 +/- 0.67 L.min-1.mm Hg-1 (mean +/- SD, P less than 0.05) at 15, 60, and 120 min. The authors conclude that epidural clonidine induces mild ventilatory and circulatory depression.

    View details for Web of Science ID A1991FN04200007

    View details for PubMedID 1903615

  • AT THE WATERS EDGE - WHERE OBSTETRICS AND ANESTHESIA MEET OBSTETRICS AND GYNECOLOGY Chestnut, D. H., Cohen, S. E. 1991; 77 (6): 965-966

    View details for Web of Science ID A1991FN40100046

    View details for PubMedID 1867684

  • ANALGESIA AFTER CESAREAN DELIVERY - PATIENT EVALUATIONS AND COSTS OF 5 OPIOID TECHNIQUES REGIONAL ANESTHESIA Cohen, S. E., Subak, L. L., Brose, W. G., Halpern, J. 1991; 16 (3): 141-149

    Abstract

    The study was designed to compare five opioid analgesic regimens administered after cesarean delivery in a routine hospital setting with respect to patients' perceptions of their pain relief and the impact of analgesic technique on recovery and hospital costs. After cesarean delivery, 684 patients received one of the following: epidural morphine, alone (EM,n = 128), or with fentanyl (EM + F,n = 245); subarachnoid morphine (n = 48); intramuscular meperidine (n = 165), or patient-controlled analgesia using meperidine (PCA, n = 98). On the first three postoperative days (Days 1-3; day of operation is Day 1) patients were surveyed regarding their impressions of their analgesia, the incidence of side effects, times to resume normal activities and satisfaction with their technique. Information regarding drug interventions and costs was obtained from anesthetic records and nursing charts. Patients receiving intramuscular and PCA opioids reported significantly more severe pain during the first 16 hours than those receiving intraspinal opioids (p less than 0.05); differences were minimal for the remainder of Day 1. Among the intraspinal groups, analgesia was best overall with EM; specifically, fentanyl did not decrease early postoperative pain. Analgesia with PCA and intramuscular opioids was similar during the first 16 hours; however, PCA patients felt they had less pain thereafter. Side effects were common in all intraspinal groups and were least frequent with PCA (p less than 0.05 versus all intraspinal groups). Times to sit, walk and drink were similar in all patients except those receiving intramuscular opioids after general anesthesia, who experienced a several-hour delay. Other aspects of recovery did not differ among the groups. Satisfaction parallelled pain relief and was better with intraspinal than with systemic opioids. Costs were greatest with PCA, although differences were small (less than 1%) relative to total hospital charges.

    View details for Web of Science ID A1991FX19600006

    View details for PubMedID 1883771

  • Maternally administered esmolol decreases fetal as well as maternal heart rate. Journal of clinical anesthesia LARSON, C. P., Shuer, L. M., Cohen, S. E. 1990; 2 (6): 427-429

    Abstract

    Fetal heart rate was monitored during the administration of esmolol 100 micrograms/kg/min to a 36-year-old, 29-week pregnant woman who was undergoing craniotomy for surgical treatment of six cerebral aneurysms. During stable general anesthesia, sodium nitroprusside was administered to induce moderate hypotension; at the same time, esmolol was infused to control maternal tachycardia. Within minutes after starting the esmolol infusion, maternal heart rate decreased from 100 beats/minute to 65 beats/minute, and fetal heart rate decreased from 160 beats/minute to 130 beats/minute. Upon termination of the infusion 3 hours later, both maternal and fetal heart rate returned to preinfusion values. No adverse effects of esmolol infusion were noted in the mother or fetus.

    View details for PubMedID 1980197

  • OXYHEMOGLOBIN SATURATION FOLLOWING CESAREAN-SECTION IN PATIENTS RECEIVING EPIDURAL MORPHINE, PCA, OR IM MEPERIDINE ANALGESIA ANESTHESIOLOGY Brose, W. G., Cohen, S. E. 1989; 70 (6): 948-953

    Abstract

    The frequency and severity of oxyhemoglobin desaturation was compared in 49 patients receiving epidural morphine, 5 mg (n = 21); patient-controlled analgesia (PCA) using meperidine (n = 20); or intramuscular (im) meperidine (n = 8) for postoperative analgesia following elective cesarean section performed with epidural anesthesia. Oxygen saturation (SpO2) was monitored for 24 h using a pulse oximeter; data were continuously collected and stored every 30 s via an interface connected to a computer. For analysis purposes, SpO2 was divided into five categories: 96-100%, 91-95%, 86-90%, 81-85%, and less than or equal to 80%. Although SpO2 remained above 95% for the majority of the monitored period, patients in all groups experienced periods of desaturation. PCA patients spent the longest cumulative time with SpO2 between 91 and 95%, 231 +/- 49 min (mean +/- SEM), compared with only 112 +/- 30 min and 152 +/- 42 min for the epidural and im groups, respectively (P less than 0.05 vs. epidural group). PCA patients also spent longest with SpO2 at 86-90% (19 +/- 10 min, vs. 6 +/- 3 and 0.5 +/- 0.3 min for the epidural and im groups, respectively), although this difference was not statistically significant. Severe desaturation episodes, defined as SpO2 less than or equal to 85% for more than 30 s, occurred in 71% of patients in the epidural group, 30% in the PCA group, and 63% in the im group (P less than 0.05 PCA vs. epidural and im).(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1989U898800011

    View details for PubMedID 2729636

  • A COMPLICATION ASSOCIATED WITH THE USE OF MIDAZOLAM ANESTHESIOLOGY ENGSTROM, R. H., Cohen, S. E. 1989; 70 (4): 719-719

    View details for Web of Science ID A1989T906500036

    View details for PubMedID 2930017

  • EPIDURAL LIDOCAINE FOR CESAREAN-SECTION - EFFECT OF VARYING EPINEPHRINE CONCENTRATION ANESTHESIOLOGY Brose, W. G., Cohen, S. E. 1988; 69 (6): 936-940

    View details for Web of Science ID A1988R353400021

    View details for PubMedID 3195763

  • SUFENTANIL ANALGESIA FOLLOWING CESAREAN-SECTION - EPIDURAL VERSUS INTRAVENOUS ADMINISTRATION ANESTHESIOLOGY Cohen, S. E., Tan, S., White, P. F. 1988; 68 (1): 129-134

    View details for Web of Science ID A1988L597700023

    View details for PubMedID 2892439

  • EPIDURAL FENTANYL BUPIVACAINE MIXTURES FOR OBSTETRIC ANALGESIA ANESTHESIOLOGY Cohen, S. E., Tan, S., Albright, G. A., Halpern, J. 1987; 67 (3): 403-407

    View details for Web of Science ID A1987J963500020

    View details for PubMedID 3631614

  • RISK OF ABORTION FOLLOWING GENERAL-ANESTHESIA FOR SURGERY DURING PREGNANCY - ANESTHETIC OR SURGICAL-PROCEDURE ANESTHESIOLOGY Cohen, S. E. 1986; 65 (6): 706-706

    View details for Web of Science ID A1986F163200033

    View details for PubMedID 3789453

  • EPIDURAL BLOOD PATCH IN OUTPATIENTS - A SIMPLER APPROACH ANESTHESIA AND ANALGESIA Cohen, S. E. 1985; 64 (4): 458-458

    View details for Web of Science ID A1985AFY5700017

    View details for PubMedID 3985395

  • ANTIEMETIC EFFICACY OF DROPERIDOL AND METOCLOPRAMIDE ANESTHESIOLOGY Cohen, S. E., Woods, W. A., Wyner, J. 1984; 60 (1): 67-69

    View details for Web of Science ID A1984SA07900015

    View details for PubMedID 6691597

  • DOES METOCLOPRAMIDE DECREASE THE VOLUME OF GASTRIC CONTENTS IN PATIENTS UNDERGOING CESAREAN-SECTION ANESTHESIOLOGY Cohen, S. E., Jasson, J., TALAFRE, M. L., CHAUVELOTMOACHON, L., Barrier, G. 1984; 61 (5): 604-607

    View details for Web of Science ID A1984TP66500025

    View details for PubMedID 6497001

  • EARLY RESPIRATORY DEPRESSION WITH EPIDURAL NARCOTIC AND INTRAVENOUS DROPERIDOL ANESTHESIOLOGY Cohen, S. E., ROTHBLATT, A. J., Albright, G. A. 1983; 59 (6): 559-560

    View details for Web of Science ID A1983RU87100014

    View details for PubMedID 6196992

  • THE ROLE OF EPIDURAL MORPHINE IN THE POSTCESAREAN PATIENT - EFFICACY AND EFFECTS ON BONDING ANESTHESIOLOGY Cohen, S. E., Woods, W. A. 1983; 58 (6): 500-504

    Abstract

    This study was designed to determine in postcesarean patients whether in addition to superior analgesic effects, epidural morphine administration results in secondary benefits in maternal well-being and maternal-infant interaction. Following elective cesarean section with bupivacaine epidural anesthesia, 40 healthy mothers received 5 mg preservative-free morphine sulfate in 10 ml of saline, either by the epidural (Group 1, n = 20) or the intravenous (Group 2, n = 20) route, in a randomized, double-blind fashion. Each received a simultaneous injection of saline by the alternate route. Analgesia in Group 1 lasted significantly longer (16.1 +/- 8.8 vs. 4.4 +/- 2.4 h, mean +/- SD; P less than 0.001), and morphine requirements in the first 24 h were significantly less (12.5 +/- 20 mg vs. 36 +/- 21 mg, P less than 0.001) than in Group 2. Seventy-four per cent of patients who received epidural morphine reported excellent analgesia, compared with only 32% of those who received intravenous morphine (P less than 0.05). Although Group 1 mothers ambulated 6 h earlier than those in Group 2 (P less than 0.02), there was no difference between the groups in time of first voiding, number of hours mothers slept, or duration of hospital stay. Mothers in both groups interacted with their infants equally well and for the same duration of time. Itching occurred in 58% of Group 1 patients and only 16% of Group 2 patients (P less than 0.01); the incidences of nausea, vomiting, and urinary retention were not statistically different between the groups. No respiratory depression was observed. Benefits of epidural morphine in this patient population appear limited to the provision of improved analgesia and earlier mobility.

    View details for Web of Science ID A1983QU80800003

    View details for PubMedID 6344699

  • THE ASPIRATION SYNDROME CLINICS IN OBSTETRICS AND GYNAECOLOGY Cohen, S. E. 1982; 9 (2): 235-254

    Abstract

    Pulmonary aspiration of gastric contents poses a continuing hazard to obstetrical patients, resulting in needless loss of life in previously healthy women. Aspiration of significant volumes of acid, alkaline or food-containing gastric contents can cause serious morbidity and mortality. Efforts to reduce the incidence of this complication should be directed at: 1. Improved training of anaesthetic personnel in obstetric anaesthesia and use of more senior staff to cover obstetrical units. 2. Meticulous care in preanaesthetic evaluation of obstetrical patients to diagnose potential intubation problems. 3. More widespread use of regional anaesthesia for vaginal and caesarean delivery. 4. Administration of small doses of non-particulate antacids to obstetrical patients before anaesthesia. 5. Possible preoperative use of cimetidine or metoclopramide, or both.

    View details for Web of Science ID A1982PS09600002

    View details for PubMedID 7140111

  • GASTRIC VOLUME IN EARLY-PREGNANCY - EFFECT OF METOCLOPRAMIDE ANESTHESIOLOGY Wyner, J., Cohen, S. E. 1982; 57 (3): 209-212

    Abstract

    This study was designed to ascertain whether gastric volume in early pregnancy is unduly large, and to determine whether preanesthetic administration of metoclopramide decreases this volume. Gastric pH and volume were measured following induction of general anesthetics in 20 nonpregnant surgical patients; 62 patients undergoing therapeutic abortion (mean gestational age, 15 +/- 3 weeks); and in 31 patients undergoing therapeutic abortions who received 10 mg metoclopramide intravenously, 15 to 30 min before anesthesia. Gastric volume was the same in the pregnant and nonpregnant control patients; in this former group, volume was not related to gestational age. In the nonpregnant control group, mean pH was lower, and there were more patients with a pH less than 2.5 than in the other groups; metoclopramide had no effect on pH. Treatment with metoclopramide resulted in significantly lower mean gastric volume (15 vs. 28 ml) and in significantly fewer patients with a gastric volume exceeding 25 ml (13% vs. 51%). Early pregnancy (less than 20 weeks gestation) confers no additional anesthetic hazard due to large gastric volume or low pH. Our data suggest that preanesthetic administration of metoclopramide may be beneficial in decreasing the risk of aspiration pneumonitis.

    View details for Web of Science ID A1982PE62500010

    View details for PubMedID 7114543

  • HIGH-DOSE EPIDURAL MORPHINE IN A TERMINALLY ILL PATIENT ANESTHESIOLOGY Woods, W. A., Cohen, S. E. 1982; 56 (4): 311-312

    View details for Web of Science ID A1982NH93700015

    View details for PubMedID 6175252

  • ANESTHESIA FOR CESAREAN-SECTION IN ACHONDROPLASTIC DWARFS ANESTHESIOLOGY Cohen, S. E. 1980; 52 (3): 264-266

    View details for Web of Science ID A1980JJ12300014

    View details for PubMedID 7369515

  • ASPIRATION SYNDROMES IN PREGNANCY ANESTHESIOLOGY Cohen, S. E. 1979; 51 (5): 375-377

    View details for Web of Science ID A1979HT20900001

    View details for PubMedID 496050

  • HALOTHANE BIOTRANSFORMATION IN ANESTHETISTS ANESTHESIOLOGY Duvaldestin, P., Mazze, R. I., HAZEBROUCK, J., Nivoche, Y., Cohen, S. E., Desmonts, J. M. 1979; 51 (1): 41-46

    Abstract

    Serum bromide levels were measured in 115 anesthetists by use of x-ray fluorescence spectrometry. Bromide levels peaked at 184 +/- 21 micron in anesthetists regularly exposed to halothane (n = 20), at 58 +/- 4 micron in anesthetists sporadically exposed to halothane (n = 71), and at 46 +/- 3 micron in nonexposed anesthetists (n = 24). Kinetic studies were carried out in five other anesthetists after ten days of exposure to halothane. Average daily halothane concentration was 19.2 +/- 3.2 ppm; duration of exposure was 3.8 +/- 0.2 hours/day. Mean serum bromide level increased from 40 +/- 4 micron before exposure to 220 +/- 36 micron on the last day of exposure. Serum bromide half-life was 14 +/- 1.7 days. The study demonstrates that anesthetists debrominate halothane in a dose-related fashion. Serum bromide levels achieved, however, were far below those reported to result in clinical bromism.

    View details for Web of Science ID A1979HB75200009

    View details for PubMedID 453592

  • COMPARISON OF A CHLOROPROCAINE-BUPIVACAINE MIXTURE WITH CHLOROPROCAINE AND BUPIVACAINE USED INDIVIDUALLY FOR OBSTETRIC EPIDURAL ANALGESIA ANESTHESIOLOGY Cohen, S. E., THURLOW, A. 1979; 51 (4): 288-292

    Abstract

    Continuous lumbar epidural anesthesia was instituted in 49 healthy parturients who were randomly assigned to three treatment groups: 14 patients received chloroprocaine, 3 per cent; 19 received bupivacaine, 0.5 per cent, and 16 received a mixture containing chloroprocaine, 1.5 per cent, and bupivacaine, 0.375 per cent. Observations relating to the characteristics of the anesthetic block and to maternal and fetal well-being were made by a trained nurse observer. Times to onset of analgesia, times to maximum block, and adequacies of analgesia were similar in all groups. Bupivacaine lasted significantly longer than chloroprocaine or the mixture (68 versus 50 and 52 min, respectively, for the first injection), and caused the least motor block. No clinical superiority could be demonstrate for the mixture as compared with bupivacaine or chloroprocaine used individually. There was no sign of material or fetal toxicity with any of the three treatment regimens.

    View details for Web of Science ID A1979HP14000002

    View details for PubMedID 484890

Conference Proceedings


  • Preloading vs. postloading of colloid for the prevention of hypotension after spinal anesthesia for cesarean section Brummel, C., Mercier, F., Fuller, A., Mathusamy, A., Lipman, S., Cohen, S. E., Riley, E. T. LIPPINCOTT WILLIAMS & WILKINS. 2004: B33-B33
  • Phenylephrine added to prophylactic ephedrine infusion during spinal anesthesia for elective cesarean section Mercier, F. J., Riley, E. T., Frederickson, W. L., Roger-Christoph, S., Benhamou, D., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 2001: 668-674

    Abstract

    Because ephedrine infusion (2 mg/min) does not adequately prevent spinal hypotension during cesarean delivery, the authors investigated whether adding phenylephrine would improve its efficacy.Thirty-nine parturients with American Society of Anesthesiologists physical status I-II who were scheduled for cesarean delivery received a crystalloid preload of 15 ml/kg. Spinal anesthesia was performed using 11 mg hyperbaric bupivacaine, 2.5 microg sufentanil, and 0.1 mg morphine. Maternal heart rate and systolic blood pressure were measured at frequent intervals. A vasopressor infusion was started immediately after spinal injection of either 2 mg/min ephedrine plus 10 microg/min phenylephrine or 2 mg/min ephedrine alone. Treatments were assigned randomly in a double-blind fashion. The infusion rate was adjusted according to systolic blood pressure using a predefined algorithm. Hypotension, defined as systolic blood pressure less than 100 mmHg and less than 80% of baseline, was treated with 6 mg ephedrine bolus doses.Hypotension occurred less frequently in the ephedrine-phenylephrine group than in the ephedrine-alone group: 37% versus 75% (P = 0.02). Ephedrine (36+/-16 mg, mean +/- SD) plus 178+/-81 microg phenylephrine was infused in former group, whereas 54+/-18 mg ephedrine was infused in the latter. Median supplemental ephedrine requirements and nausea scores (0-3) were less in the ephedrine-phenylephrine group (0 vs. 12 mg, P = 0.02; and 0 vs. 1.5, P = 0.01, respectively). Umbilical artery pH values were significantly higher in the ephedrine-phenylephrine group than in the group that received ephedrine alone (7.24 vs. 7.19). Apgar scores were similarly good in both groups.Phenylephrine added to an infusion of ephedrine halved the incidence of hypotension and increased umbilical cord pH.

    View details for Web of Science ID 000170872900016

    View details for PubMedID 11575540

  • Walking with labor epidural analgesia - The impact of bupivacaine concentration and a lidocaine-epinephrine test dose Cohen, S. E., Yeh, J. Y., Riley, E. T., Vogel, T. M. LIPPINCOTT WILLIAMS & WILKINS. 2000: 387-392

    Abstract

    Regional analgesia techniques for labor that permit ambulation are popular among parturients. This study evaluated the influence of bupivacaine bolus concentration and a 3-ml 1.5% lidocaine-epinephrine test dose, on analgesic effectiveness and the ability to walk after block placement.Using a randomized double-blind study design, epidural analgesia was initiated in 60 parturients undergoing labor as follows: Group TD/B.0625 received a 3-ml lidocaine-epinephrine test dose + 12 ml bupivacaine, 0.0625%; group TD/B.125 received a 3-ml test dose + 12 ml bupivacaine, 0.125%; group B.0625 received 15 ml bupivacaine, 0.0625% (no test dose); and group B.125 received 15 ml bupivacaine, 0.125% (no test dose). Initial boluses in all groups contained 10 microg sufentanil. Bupivacaine, 0.0625%, with 0.33 microg/ml sufentanil was infused throughout labor at 13.5-15 ml/h. Analgesia balance, proprioception, motor block, and patient ability to stand and walk were evaluated at various intervals.A bolus of 0.125% bupivacaine containing sufentanil, without a previous test dose, proved to be optimal with respect to analgesia and early ambulation. When a test dose was given before bupivacaine, 0.125%, fewer women walked within 1 h of block placement. Bupivacaine, 0.0625%, with sufentanil, with or without a test dose, provided inadequate analgesia, necessitating additional bupivacaine, which impaired the ability to walk. A high percentage of women in all groups (73-93%) walked at some stage during labor.Omitting a lidocaine-epinephrine test dose and using 0.125% bupivacaine for the initial bolus should permit ambulation in the early postblock period for most parturients who elect this option.

    View details for Web of Science ID 000085078600015

    View details for PubMedID 10691224

  • Intrathecal sufentanil for labor analgesia does not cause a sympathectomy Riley, E. T., Walker, D., Hamilton, C. L., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 874-878

    Abstract

    Intrathecal sufentanil (ITS) is frequently used to provide analgesia during labor. Decreases in blood pressure and sensory changes in this circumstance suggest that ITS may have a local anesthetic effect and thus cause a sympathectomy. To determine whether ITS given to laboring women causes a sympathectomy, the authors evaluated central and lower extremity temperature changes after ITS administration. These findings were compared with those in a control group of women having spinal anesthesia with bupivacaine for elective cesarean section in whom an extensive sympathectomy was expected.Twenty parturients classified as American Society of Anesthesiologists' physical status 1 or 2 had temperatures measured centrally, at the calf, and at the great toe at frequent intervals after receiving 10 microg ITS for labor analgesia (sufentanil group, n = 10), or hyperbaric bupivacaine 12 mg in their spinal anesthetic for cesarean section (bupivacaine group, n = 10). Calf-to-toe temperature indices (C-T) were calculated by subtracting toe temperature from calf temperature. A decrease in this index means that the toe had warmed compared with the calf and is an indication of vasodilation and a sympathectomy.There was no significant change in the C-T indices or central temperature in the sufentanil group, but the C-T indices and central temperature decreased significantly in the bupivacaine group.The decreases in the C-T index and central temperature in the bupivacaine group indicate the presence of a sympathectomy. The lack of change in the C-T indices and central temperature in the sufentanil group indicates that no significant vasodilation occurred. Therefore, the decrease in blood pressure seen after ITS administration for labor analgesia is unlikely to be the result of a sympathectomy.

    View details for Web of Science ID A1997YD11700022

    View details for PubMedID 9357890

  • Intrathecal sufentanil for labor analgesia: Do sensory changes predict better analgesia and greater hypotension? Riley, E. T., Ratner, E. F., Cohen, S. E. LIPPINCOTT WILLIAMS & WILKINS. 1997: 346-351

    Abstract

    Sensory changes and hypotension occur after intrathecal sufentanil (ITS) is given during labor. The goal of this study was to determine whether sensory changes are predictive of hemodynamic changes or duration of pain relief. We also examined whether sensory and hemodynamic changes relate to the concentration of ITS administered. Forty-five ASA physical status I and II women in active labor were randomly assigned to receive 10 micrograms ITS diluted in either 1, 2, or 3 mL of normal saline (15 in each group). An observer blinded to treatment recorded verbal pain scores, blood pressure, and sensory changes to light touch, pinprick, and cold at frequent intervals. Excellent analgesia was obtained in 42 of 45 patients. There were no differences among the groups with respect to the number of patients with sensory changes, the duration of analgesia or sensory changes, the quality of analgesia, or the severity of hypotension. The groups were therefore combined for further analyses. Among this combined group, the duration of analgesia was 99 +/- 7 min (mean +/- SE). Cold, pinprick, and light touch sensation were decreased in 66%, 50%, and 33% of patients, respectively. Motor block was absent in all patients. The duration and quality of analgesia were similar in subjects with and without sensory changes. Systolic blood pressure decreased 23 +/- 2 mm Hg (P < 0.05) during the first 30 min after ITS, and six patients were given ephedrine. The magnitude of blood pressure change was not affected by the diluent volume or the presence of sensory changes. Because sensory changes were not predictive of the duration or quality of analgesia or the degree of hemodynamic change, we conclude that analgesia with ITS is predominantly mediated via spinal cord opioid receptors rather than by a local anesthetic-type conduction blockade.

    View details for Web of Science ID A1997WF15900019

    View details for PubMedID 9024026

Stanford Medicine Resources: