Alexis Davis

All Publications

• Perinatal Neuroprotection for Extremely Preterm Infants AMERICAN JOURNAL OF PERINATOLOGY Davis, A. S., Berger, V. K., Chock, V. Y. 2016; 33 (3): 290-296

  Abstract

  The preterm brain is vulnerable to injury through multiple mechanisms, from direct cerebral injury through ischemia and hemorrhage, indirect injury through inflammatory processes, and aberrations in growth and development. While prevention of preterm birth is the best neuroprotective strategy, this is not always possible. This article will review various obstetric and neonatal practices that have been shown to confer a neuroprotective effect on the developing brain.

  View details for DOI 10.1055/s-0035-1571148

  View details for Web of Science ID 000370589700010

  View details for PubMedID 26799965

• Amplitude-integrated electroencephalography: a survey of practices in the United States. American journal of perinatology Shah, N. A., Van Meurs, K. P., Davis, A. S. 2015; 32 (8): 755-760

  Abstract

  Objective Amplitude-integrated electroencephalography (aEEG) is a simplified method for continuous monitoring of brain activity in the neonatal intensive care unit (NICU). Our objective was to describe current aEEG use in the United States. Study Design An online survey was distributed to the American Academy of Pediatrics Section on Perinatal Pediatrics' list serve. Result A total of 654 surveys were received; 55% of respondents reported using aEEG. aEEG was utilized more often in academic and levels III and IV NICUs; hypoxic-ischemic encephalopathy and suspected seizures were the most common indications for use. aEEG was primarily interpreted by neonatologists (87%), with approximately half reporting either self-teaching or hospital-based training for interpretation. For those not using aEEG, uncertain clinical benefit (40%) and cost (17%) were reported as barriers to use. Conclusion More than half of neonatologists utilize aEEG, with practice variation by NICU setting. Barriers to wider adoption include education regarding potential benefit, training, and cost.

  View details for DOI 10.1055/s-0034-1395483

  View details for PubMedID 25519200

• Serial aEEG recordings in a cohort of extremely preterm infants: feasibility and safety JOURNAL OF PERINATOLOGY Davis, A. S., Gantz, M. G., Do, B., Shankaran, S., Hamrick, S. E., Kennedy, K. A., TYSON, J. E., Chalak, L. F., Laptook, A. R., Goldstein, R. F., Hintz, S. R., Das, A., Higgins, R. D., Ball, M. B., HALE, E. C., Van Meurs, K. P. 2015; 35 (5): 373-378

  Abstract

  Objective:Amplitude-integrated electroencephalography (aEEG) monitoring is increasing in the neonatal population, but the safety and feasibility of performing aEEG in extremely preterm infants have not been systematically evaluated.Study Design:Inborn infants 23(0/7) to 28(6/7) weeks gestation or birth weight 401 to 1000 g were eligible. Serial, 6-h aEEG recordings were obtained from first week of life until 36 weeks postmenstrual age. Adverse events were documented, and surveys evaluated the impact of the aEEGs on routine care. Success of performing aEEGs according to protocol and aEEG quality were assessed.Result:A total of 102 infants were enrolled, with 755 recordings performed. 83% of recordings were performed according to schedule, and 96% were without adverse event. Bedside nurses reported no interference with routine care for 89% of recordings. 92% of recordings had acceptable signal quality.Conclusion:Serial aEEG monitoring is safe in preterm infants, with few adverse events and general acceptance by nursing staff.Journal of Perinatology advance online publication, 4 December 2014; doi:10.1038/jp.2014.217.

  View details for DOI 10.1038/jp.2014.217

  View details for Web of Science ID 000353565200013

• A randomized clinical trial of therapeutic hypothermia mode during transport for neonatal encephalopathy. journal of pediatrics Akula, V. P., Joe, P., Thusu, K., Davis, A. S., Tamaresis, J. S., Kim, S., Shimotake, T. K., Butler, S., Honold, J., Kuzniewicz, M., Desandre, G., Bennett, M., Gould, J., Wallenstein, M. B., Van Meurs, K. 2015; 166 (4): 856-61 e1 2

  Abstract

  To determine if temperature regulation is improved during neonatal transport using a servo-regulated cooling device when compared with standard practice.We performed a multicenter, randomized, nonmasked clinical trial in newborns with neonatal encephalopathy cooled during transport to 9 neonatal intensive care units in California. Newborns who met institutional criteria for therapeutic hypothermia were randomly assigned to receive cooling according to usual center practices vs device servo-regulated cooling. The primary outcome was the percentage of temperatures in target range (33°-34°C) during transport. Secondary outcomes included percentage of newborns reaching target temperature any time during transport, time to target temperature, and percentage of newborns in target range 1 hour after cooling initiation.One hundred newborns were enrolled: 49 to control arm and 51 to device arm. Baseline demographics did not differ with the exception of cord pH. For each subject, the percentage of temperatures in the target range was calculated. Infants cooled using the device had a higher percentage of temperatures in target range compared with control infants (median 73% [IQR 17-88] vs 0% [IQR 0-52], P < .001). More subjects reached target temperature during transport using the servo-regulated device (80% vs 49%, P <.001), and in a shorter time period (44 ± 31 minutes vs 63 ± 37 minutes, P = .04). Device-cooled infants reached target temperature by 1 hour with greater frequency than control infants (71% vs 20%, P < .001).Cooling using a servo-regulated device provides more predictable temperature management during neonatal transport than does usual care for outborn newborns with neonatal encephalopathy.

  View details for DOI 10.1016/j.jpeds.2014.12.061

  View details for PubMedID 25684087

• Fetal centers and the role of the neonatologist in complex fetal care. American journal of perinatology Davis, A. S., Chock, V. Y., Hintz, S. R. 2014; 31 (7): 549-556

  Abstract

  As prenatal imaging and genetic diagnostic techniques developed, clinicians knew earlier and with greater accuracy of the extent and severity of fetal anomalies. This, coupled with an acute awareness of high rates of death or devastating neonatal morbidities in some cases, drove efforts to create innovative fetal interventions. However, with advances in neonatal quaternary care, infants with even the most complex congenital anomalies now have a substantially greater chance of survival. But many still require highly coordinated intensive care from the moment of delivery, have lengthy and complicated hospitalizations, and need ongoing complex care and services. Therefore, a new vision of complex fetal medicine must evolve, actively integrating robust multidisciplinary involvement in collaborative counseling, planning, and management. The clinical arc visualized for complex fetal patients should shift toward a comprehensive continuum of care concept-extending from fetal life, through neonatal intensive care, to childhood. The neonatologist plays a critical role in bridging this trajectory, coordinating complex processes to a smooth delivery and neonatal plan, counseling and preparing expectant mothers, and integrating many components of subspecialty input for families and other fetal team members. Neonatologists' engagement and perspective can substantively inform the clinical and strategic direction for fetal centers.

  View details for DOI 10.1055/s-0034-1371709

  View details for PubMedID 24705973

• Outcomes of extremely preterm infants following severe intracranial hemorrhage JOURNAL OF PERINATOLOGY Davis, A. S., Hintz, S. R., Goldstein, R. F., Ambalavanan, N., Bann, C. M., Stoll, B. J., Bell, E. F., Shankaran, S., Laptook, A. R., Walsh, M. C., HALE, E. C., Newman, N. S., Das, A., Higgins, R. D. 2014; 34 (3): 203-208

  Abstract

  Objective:Severe intracranial hemorrhage (ICH) is an important prognostic variable in extremely preterm (EPT) infants. We examined imaging and clinical variables that predict outcomes in EPT infants with severe ICH.Study design:Retrospective analysis of 353 EPT infants with severe ICH. Outcomes were compared by examining: (i) unilateral vs bilateral ICH; and (ii) presence vs absence of hemorrhagic parenchymal infarction (HPI). Regression analyses identified variables associated with death or neurodevelopmental impairment (NDI).Result:Bilateral ICH and HPI had higher rates of adverse outcomes and were independently associated with death/NDI. HPI was the most important variable for infants of lower birth weight, and bilateral ICH for larger infants. For infants surviving to 36 weeks, shunt placement was most associated with death/NDI.Conclusion:Bilateral ICH and the presence of HPI in EPT infants with severe ICH are associated with death/NDI, though the importance depends on birth weight and survival to 36 weeks.

  View details for DOI 10.1038/jp.2013.162

  View details for Web of Science ID 000332075200009

  View details for PubMedID 24370654

• Outcomes of extremely low birthweight infants with acidosis at birth. Archives of disease in childhood. Fetal and neonatal edition Randolph, D. A., Nolen, T. L., Ambalavanan, N., Carlo, W. A., Peralta-Carcelen, M., Das, A., Bell, E. F., Davis, A. S., Laptook, A. R., Stoll, B. J., Shankaran, S., Higgins, R. D. 2014

  Abstract

  To test the hypothesis that acidosis at birth is associated with the combined primary outcome of death or neurodevelopmental impairment (NDI) in extremely low birthweight (ELBW) infants, and to develop a predictive model of death/NDI exploring perinatal acidosis as a predictor variable.The study population consisted of ELBW infants born between 2002 and 2007 at National Institute of Child Health and Development (NICHD) Neonatal Research Network hospitals. Infants with cord blood gas data and documentation of either mortality prior to discharge or 18-22 month neurodevelopmental outcomes were included. Multiple logistic regression analysis was used to determine the contribution of perinatal acidosis, defined as a cord blood gas with a pH<7 or base excess (BE) <-12, to death/NDI in ELBW infants. In addition, a multivariable model predicting death/NDI was developed.3979 patients were identified of whom 249 had a cord gas pH<7 or BE<-12 mEq/L. 2124 patients (53%) had the primary outcome of death/NDI. After adjustment for confounding variables, pH<7 and BE<-12 mEq/L were each significantly associated with death/NDI (OR=2.5 (1.6, 4.2) and OR=1.5 (1.1, 2.0), respectively). However, inclusion of pH or BE did not improve the ability of the multivariable model to predict death/NDI.Perinatal acidosis is significantly associated with death/NDI in ELBW infants. Perinatal acidosis is infrequent in ELBW infants, however, and other factors are more important in predicting death/NDI.

  View details for DOI 10.1136/archdischild-2013-304179

  View details for PubMedID 24554564

• Therapeutic hypothermia during neonatal transport: data from the California Perinatal Quality Care Collaborative (CPQCC) and California Perinatal Transport System (CPeTS) for 2010 JOURNAL OF PERINATOLOGY Akula, V. P., Gould, J. B., DAVIS, A. S., Hackel, A., Oehlert, J., Van Meurs, K. P. 2013; 33 (3): 194-197

  Abstract

  To evaluate cooling practices and neonatal outcomes in the state of California during 2010 using the California Perinatal Quality Care Collaborative and California Perinatal Transport System databases.Database analysis to determine the perinatal and neonatal demographics and outcomes of neonates cooled in transport or after admission to a cooling center.Of the 223 infants receiving therapeutic hypothermia for hypoxic ischemic encephalopathy (HIE) in California during 2010, 69% were cooled during transport. Despite the frequent use of cooling in transport, cooling center admission temperature was in the target range (33-34 °C) in only 62 (44%). Among cooled infants, gestational age was <35 weeks in 10 (4.5%). For outborn and transported infants, chronologic age at the time of cooling initiation was >6 h in 20 (11%). When initiated at the birth hospital, cooling was initiated at <6 h of age in 131 (92.9%).More than half of the infants cooled in transport do not achieve target temperature by the time of arrival at the cooling center. The use of cooling devices may improve temperature regulation on transport.

  View details for DOI 10.1038/jp.2012.144

  View details for Web of Science ID 000315664700006

  View details for PubMedID 23223159

• Conservatively Managed Fetal Goiter: An Alternative to in utero Therapy FETAL DIAGNOSIS AND THERAPY Blumenfeld, Y. J., Davis, A., Milan, K., Chueh, J., Hudgins, L., Barth, R. A., Hintz, S. R. 2013; 34 (3): 184-187

  Abstract

  Fetal goiter may arise from a variety of etiologies including iodine deficiency, overtreatment of maternal Graves' disease, inappropriate maternal thyroid replacement and, rarely, congenital hypothyroidism. Fetal goiter is often associated with a retroflexed neck and polyhydramnios, raising concerns regarding airway obstruction in such cases. Prior reports have advocated for cordocentesis and intra-amniotic thyroid hormone therapy in order to confirm the diagnosis of fetal thyroid dysfunction, reduce the size of the fetal goiter, reduce polyhydramnios, aid with the assistance of maternal thyroid hormone therapy and reduce fetal malpresentation. We report two cases of conservatively managed fetal goiter, one resulting in a vaginal delivery, and no evidence of postnatal respiratory distress despite the presence of polyhydramnios and a retroflexed neck on prenatal ultrasound. © 2013 S. Karger AG, Basel.

  View details for DOI 10.1159/000353387

  View details for Web of Science ID 000326134700010

• Therapeutic Hypothermia during Neonatal Transport: Current Practices in California AMERICAN JOURNAL OF PERINATOLOGY Akula, V. P., Davis, A. S., Gould, J. B., Van Meurs, K. 2012; 29 (5): 319-326

  Abstract

  Therapeutic hypothermia initiated at <6 hours of age reduces death and disability in newborns ? 36 weeks' gestation with moderate to severe hypoxic ischemic encephalopathy. Given the limited therapeutic window, cooling during transport becomes a necessity. Our goal was to describe the current practice of therapeutic hypothermia during transport used in the state of California. All level III neonatal intensive care units (NICUs) were contacted to identify those units providing therapeutic hypothermia. An electronic questionnaire was sent to obtain basic information. Responses were received from 28 (100%) NICUs performing therapeutic hypothermia; 26 NICUs were cooling newborns and two were in the process of program development. Eighteen (64%) centers had cooled a patient in transport, six had not yet cooled in transport, and two do not plan to cool in transport. All 18 centers use passive cooling, except for two that perform both passive and active cooling, and 17 of 18 centers recommend initiation of cooling at the referral hospital. Reported difficulties include overcooling, undercooling, and bradycardia. Cooling on transport is being performed by majority of NICUs providing therapeutic hypothermia. Clinical protocols and devices for cooling in transport are essential to ensure safety and efficacy.

  View details for DOI 10.1055/s-0031-1295661

  View details for Web of Science ID 000302962200001

  View details for PubMedID 22143969

• Association of Antenatal Corticosteroids With Mortality and Neurodevelopmental Outcomes Among Infants Born at 22 to 25 Weeks' Gestation JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Carlo, W. A., McDonald, S. A., Fanaroff, A. A., Vohr, B. R., Stoll, B. J., Ehrenkranz, R. A., Andrews, W. W., Wallace, D., Das, A., Bell, E. F., Walsh, M. C., Laptook, A. R., Shankaran, S., Poindexter, B. B., Hale, E. C., Newman, N. S., Davis, A. S., Schibler, K., Kennedy, K. A., Sanchez, P. J., Van Meurs, K. P., Goldberg, R. N., Watterberg, K. L., Faix, R. G., Frantz, I. D., Higgins, R. D. 2011; 306 (21): 2348-2358

  Abstract

  Current guidelines, initially published in 1995, recommend antenatal corticosteroids for mothers with preterm labor from 24 to 34 weeks' gestational age, but not before 24 weeks due to lack of data. However, many infants born before 24 weeks' gestation are provided intensive care.To determine if use of antenatal corticosteroids is associated with improvement in major outcomes for infants born at 22 and 23 weeks' gestation.Cohort study of data collected prospectively on inborn infants with a birth weight between 401 g and 1000 g (N = 10,541) born at 22 to 25 weeks' gestation between January 1, 1993, and December 31, 2009, at 23 academic perinatal centers in the United States. Certified examiners unaware of exposure to antenatal corticosteroids performed follow-up examinations on 4924 (86.5%) of the infants born between 1993 and 2008 who survived to 18 to 22 months. Logistic regression models generated adjusted odds ratios (AORs), controlling for maternal and neonatal variables.Mortality and neurodevelopmental impairment at 18 to 22 months' corrected age.Death or neurodevelopmental impairment at 18 to 22 months was significantly lower for infants who had been exposed to antenatal corticosteroids and were born at 23 weeks' gestation (83.4% with exposure to antenatal corticosteroids vs 90.5% without exposure; AOR, 0.58 [95% CI, 0.42-0.80]), at 24 weeks' gestation (68.4% with exposure to antenatal corticosteroids vs 80.3% without exposure; AOR, 0.62 [95% CI, 0.49-0.78]), and at 25 weeks' gestation (52.7% with exposure to antenatal corticosteroids vs 67.9% without exposure; AOR, 0.61 [95% CI, 0.50-0.74]) but not in those infants born at 22 weeks' gestation (90.2% with exposure to antenatal corticosteroids vs 93.1% without exposure; AOR, 0.80 [95% CI, 0.29-2.21]). If the mothers had received antenatal corticosteroids, the following events occurred significantly less in infants born at 23, 24, and 25 weeks' gestation: death by 18 to 22 months; hospital death; death, intraventricular hemorrhage, or periventricular leukomalacia; and death or necrotizing enterocolitis. For infants born at 22 weeks' gestation, the only outcome that occurred significantly less was death or necrotizing enterocolitis (73.5% with exposure to antenatal corticosteroids vs 84.5% without exposure; AOR, 0.54 [95% CI, 0.30-0.97]).Among infants born at 23 to 25 weeks' gestation, antenatal exposure to corticosteroids compared with nonexposure was associated with a lower rate of death or neurodevelopmental impairment at 18 to 22 months.

  View details for Web of Science ID 000297680300020

  View details for PubMedID 22147379

• Perspectives of physician parents in the NICU Children's Health Care Batton B, Verhulst S, Batton D, Davis A, Collin A, Walsh M 2011; 40 (4): 326
• Seizures in Extremely Low Birth Weight Infants Are Associated with Adverse Outcome JOURNAL OF PEDIATRICS Davis, A. S., Hintz, S. R., Van Meurs, K. P., Li, L., Das, A., Stoll, B. J., Walsh, M. C., Pappas, A., Bell, E. F., Laptook, A. R., Higgins, R. D. 2010; 157 (5): 720-U47

  Abstract

  To examine risk factors for neonatal clinical seizures and to determine the independent association with death or neurodevelopmental impairment (NDI) in extremely low birth weight (ELBW) infants.A total of 6499 ELBW infants (401-1000 g) surviving to 36 weeks postmenstrual age (PMA) were included in this retrospective study. Unadjusted comparisons were performed between infants with (n = 414) and without (n = 6085) clinical seizures during the initial hospitalization. Using multivariate logistic regression modeling, we examined the independent association of seizures with late death (after 36 weeks PMA) or NDI after controlling for multiple demographic, perinatal, and neonatal variables.Infants with clinical seizures had a greater proportion of neonatal morbidities associated with poor outcome, including severe intraventricular hemorrhage, sepsis, meningitis, and cystic periventricular leukomalacia (all P < .01). Survivors were more likely to have NDI or moderate-severe cerebral palsy at 18 to 22 months corrected age (both P < .01). After adjusting for multiple confounders, clinical seizures remained significantly associated with late death or NDI (odds ratio, 3.15; 95% CI, 2.37-4.19).ELBW infants with clinical seizures are at increased risk for adverse neurodevelopmental outcome, independent of multiple confounding factors.

  View details for DOI 10.1016/j.jpeds.2010.04.065

  View details for Web of Science ID 000283045900008

  View details for PubMedID 20542294

• Human Neural Stem Cell Grafts Modify Microglial Response and Enhance Axonal Sprouting in Neonatal Hypoxic-Ischemic Brain Injury STROKE Daadi, M. M., Davis, A. S., Arac, A., Li, Z., Maag, A., Bhatnagar, R., Jiang, K., Sun, G., Wu, J. C., Steinberg, G. K. 2010; 41 (3): 516-523

  Abstract

  Hypoxic-ischemic (HI) brain injury in newborn infants represents a major cause of cerebral palsy, development delay, and epilepsy. Stem cell-based therapy has the potential to rescue and replace the ischemic tissue caused by HI and to restore function. However, the mechanisms by which stem cell transplants induce functional recovery are yet to be elucidated. In the present study, we sought to investigate the efficacy of human neural stem cells derived from human embryonic stem cells in a rat model of neonatal HI and the mechanisms enhancing brain repair.The human neural stem cells were genetically engineered for in vivo molecular imaging and for postmortem histological tracking. Twenty-four hours after the induction of HI, animals were grafted with human neural stem cells into the forebrain. Motor behavioral tests were performed the fourth week after transplantation. We used immunocytochemistry and neuroanatomical tracing to analyze neural differentiation, axonal sprouting, and microglia response. Treatment-induced changes in gene expression were investigated by microarray and quantitative polymerase chain reaction.Bioluminescence imaging permitted real time longitudinal tracking of grafted human neural stem cells. HI transplanted animals significantly improved in their use of the contralateral impeded forelimb and in the Rotorod test. The grafts showed good survival, dispersion, and differentiation. We observed an increase of uniformly distributed microglia cells in the grafted side. Anterograde neuroanatomical tracing demonstrated significant contralesional sprouting. Microarray analysis revealed upregulation of genes involved in neurogenesis, gliogenesis, and neurotrophic support.These results suggest that human neural stem cell transplants enhance endogenous brain repair through multiple modalities in response to HI.

  View details for DOI 10.1161/STROKEAHA.109.573691

  View details for Web of Science ID 000274799600019

  View details for PubMedID 20075340

• Bedside cerebral monitoring to predict neurodevelopmental outcomes NeoReviews Chock VY, Davis AS 2009; 10 (3): e121-e129
• Challenges of giant omphalocele: from fetal diagnosis to follow-up NeoReviews Davis AS, Blumenfeld Y, Rubesova E, Abrajano C, El-Sayed YY, Dutta S, Barth RA, Hintz SR 2008; 9 (8): e338-e347
• Gene therapy using SOD1 protects striatal neurons from experimental stroke NEUROSCIENCE LETTERS Davis, A. S., Zhao, H., Sun, G. H., Sapolsky, R. M., Steinberg, G. K. 2007; 411 (1): 32-36

  Abstract

  Reactive oxygen species contribute to neuronal death following cerebral ischemia. Prior studies using transgenic animals have demonstrated the neuroprotective effect of the antioxidant, copper/zinc superoxide dismutase (SOD1). In this study, we investigated whether SOD1 overexpression using gene therapy techniques in non-transgenic animals would increase neuronal survival. A neurotropic, herpes simplex virus-1 (HSV-1) vector containing the SOD1 gene was injected into the striatum either before or after transient focal cerebral ischemia. Striatal neuron survival at 2 days was improved by 52% when vector was delivered 12-15 h prior to ischemia and by 53% when vector delivery was delayed 2 h following ischemia. These data add to the growing literature, which suggests that an antioxidant approach, perhaps by employing gene therapy techniques, may be beneficial in the treatment of stroke.

  View details for DOI 10.1016/j.neulet.2006.08.089

  View details for Web of Science ID 000243153100007

  View details for PubMedID 17110031