Predicting outcomes of neonates diagnosed with hypoxemic-ischemic encephalopathy

Single-Center Experience with Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy in Infants with <36 Weeks' Gestation

OBJECTIVE

 Hypoxic-ischemic encephalopathy (HIE) is a leading cause of morbidity and mortality in neonates. Therapeutic hypothermia (TH) has improved outcomes and mortality in infants with >36 weeks' gestational age (GA) with moderate-to-severe HIE. There are limited data on the safety and efficacy of TH in preterm infants with HIE. This study describes our experience and examines the safety of TH in neonates with <36 weeks' GA.

STUDY DESIGN

A single-center, retrospective study of preterm neonates born at <36 weeks' GA with moderate-to-severe HIE and treated with TH, compared to a cohort of term neonates with HIE (≥37 weeks' GA), was conducted. The term cohort was matched for degree of background abnormality on electroencephalogram, sex, inborn versus outborn status, and birth year. Medical records were reviewed for pregnancy and delivery complications, need for transfusion, sedation and antiseizure medications, electroencephalography and imaging findings, and in-hospital mortality.

RESULTS

 Forty-two neonates born at <36 weeks' GA with HIE received TH between 2005 and 2022. Data from 42 term neonates were analyzed for comparison. The average GA of the preterm cohort was 34.6 weeks and 39.3 weeks for the term cohort. Apgar scores, degree of acidosis, and need for blood product transfusions were similar between groups. Preterm infants were more likely to require inotropic support (55 vs. 29%, p = 0.026) and hydrocortisone (36 vs. 12%, p = 0.019) for hypotension. The proportion of infants without evidence of injury on magnetic resonance imaging was similar in both groups: 43 versus 50% in preterm and term infants, respectively. No significant difference was found in mortality between groups.

CONCLUSION

 In this single-center cohort, TH in preterm infants appears to be as safe as in term infants, with no significant increase in intracranial bleeds or mortality. Preterm infants more frequently required inotropes and steroids for hypotension. Further research is needed to determine efficacy of TH in preterm infants.

KEY POINTS

· TH is used off-protocol in preterm infants.. · Preterm and term infants have similar mortality.. · Preterm cohort required more inotropic support..

Evolution of the Sarnat exam and association with 2-year outcomes in infants with moderate or severe hypoxic-ischaemic encephalopathy: a secondary analysis of the HEAL Trial

OBJECTIVE

To study the association between the Sarnat exam (SE) performed before and after therapeutic hypothermia (TH) and outcomes at 2 years in infants with moderate or severe hypoxic-ischaemic encephalopathy (HIE).

DESIGN

Secondary analysis of the High-dose Erythropoietin for Asphyxia and EncephaLopathy Trial. Adjusted ORs (aORs) for death or neurodevelopmental impairment (NDI) based on SE severity category and change in category were constructed, adjusting for sedation at time of exam. Absolute SE Score and its change were compared for association with risk for death or NDI using locally estimated scatterplot smoothing curves.

SETTING

Randomised, double-blinded, placebo-controlled multicentre trial including 17 centres across the USA.

PATIENTS

479/500 enrolled neonates who had both a qualifying SE (qSE) before TH and a SE after rewarming (rSE).

INTERVENTIONS

Standardised SE was used across sites before and after TH. All providers underwent standardised SE training.

MAIN OUTCOME MEASURES

Primary outcome was defined as the composite outcome of death or any NDI at 22-36 months.

RESULTS

Both qSE and rSE were associated with the primary outcome. Notably, an aOR for primary outcome of 6.2 (95% CI 3.1 to 12.6) and 50.3 (95% CI 13.3 to 190) was seen in those with moderate and severe encephalopathy on rSE, respectively. Persistent or worsened severity on rSE was associated with higher odds for primary outcome compared with those who improved, even when qSE was severe.

CONCLUSION

Both rSE and change between qSE and rSE were strongly associated with the odds of death/NDI at 22-36 months in infants with moderate or severe HIE.

Maternal and neonatal complications in pregnancies with and without pre-gestational diabetes mellitus

OBJECTIVES

To compare pregnancy complications in pregnancies with and without pre-gestational diabetes mellitus (DM) managed in a multidisciplinary high-risk diabetes antenatal clinic.

METHODS

This screening cohort study was undertaken at a large maternity unit in the United Kingdom between January 2010 and December 2022. We included singleton pregnancies that booked at our unit at 11-13 weeks' gestation. Univariate and multivariate logistic regression analysis was carried out to determine risks of complications in pregnancies with type 1 and type 2 DM after adjusting for maternal and pregnancy characteristics. Effect sizes were expressed as absolute risks (AR) and odds ratio (OR) (95 % confidence intervals [CI]).

RESULTS

The study population included 53,649 singleton pregnancies, including 509 (1.0 %) with pre-existing DM and 49,122 (99.0 %) without diabetes. Multivariate logistic regression analysis demonstrated that there was a significant contribution from pre-existing DM in prediction of adverse outcomes, including antenatal complications such as fetal defects, stillbirth, preterm delivery, polyhydramnios, preeclampsia and delivery of large for gestational age (LGA) neonates; intrapartum complications such as caesarean delivery (CS) and post-partum haemorrhage; and neonatal complications including admission to neonatal intensive care unit, hypoglycaemia, jaundice and hypoxic ischaemic encephalopathy (HIE). In particular, there was a 5-fold increased risk of stillbirth and HIE.

CONCLUSIONS

The maternal and neonatal complications in pregnancies with pre-existing DM are significantly increased compared to those without DM despite a decade of intensive multidisciplinary antenatal care. Further research is required to investigate strategies and interventions to prevent morbidity and mortality in pregnancies with pre-gestational DM.

Characteristics and outcomes of neonates with intrapartum asphyxia managed with therapeutic hypothermia in a public tertiary hospital in South Africa

BACKGROUND

In randomized clinical trials, therapeutic hypothermia (TH) has been shown to reduce death and/or moderate-to-severe disability in neonates with hypoxic ischemic encephalopathy (HIE) in high-income countries, while this has not consistently been the case in low-and middle-income countries (LMICs). Many studies reporting on outcomes of neonates with HIE managed with TH are those conducted under controlled study conditions, and few reporting in settings where this intervention is offered as part of standard of care, especially from LMICs. In this study we report on short-term outcomes of neonates with moderate-to-severe HIE where TH was offered as part of standard of care.

OBJECTIVE

To determine characteristics and mortality rate at hospital discharge in neonates with moderate-to-severe HIE.

METHODS

Hospital records of neonates with intrapartum asphyxia were reviewed for clinical findings, management with TH (cooled or non-cooled) and mortality at hospital discharge. Inclusion criteria were birthweight ≥ 1800 g, gestational age ≥ 36 weeks and moderate-to-severe HIE. Comparisons were made between survivors and non-survivors in cooled and/or non-cooled neonates.

RESULTS

Intrapartum asphyxia was diagnosed in 856 neonates, with three having no recorded HIE status; 30% (258/853) had mild HIE, and 595/853 (69%) with moderate-to-severe HIE. The overall incidence of intrapartum asphyxia was 8.8/1000 live births. Of the 595 with moderate-to-severe HIE, three had no records on cooling and 67% (399/592) were cooled. Amongst 193 non-cooled neonates, 126 (67%) had documented reasons for not being cooled with common reasons being a moribund neonate (54.0%), equipment unavailability (11.1%), pulmonary hypertension (9.5%), postnatal age > 6 h on admission (8.7%), and improvement in severity of encephalopathy (8.7%). Overall mortality was 29.0%, being 17.0% and 53.4% in cooled and non-cooled infants respectively. On multivariate analysis, the only factor associated with mortality was severe encephalopathy.

CONCLUSION

Overall mortality in neonates with moderate-to-severe HIE was 29.0% and 17.0% in those who were cooled. Cooling was not offered to all neonates mainly because of severe clinical illness, equipment unavailability and delayed presentation, making it difficult to assess overall impact of this intervention. Prospective clinical studies need to be conducted in LMIC to further assess effect of TH in short and long-term outcomes.

Glucose-to-lactate ratio and neurodevelopment in infants with hypoxic-ischemic encephalopathy: an observational study

We aimed to assess the glucose and lactate kinetics during therapeutic hypothermia (TH) in infants with hypoxic-ischemic encephalopathy and its relationship with longitudinal neurodevelopment. We measured glucose and lactate concentrations before TH and on days 2 and 3 in infants with mild, moderate, and severe hypoxic-ischemic encephalopathy (HIE). Neurodevelopment was assessed at 2 years. Participants were grouped according to the neurodevelopmental outcome into favorable (FO) or unfavorable (UFO). Eighty-eight infants were evaluated at follow-up, 34 for the FO and 54 for the UFO group. Severe hypo- (< 2.6 mmol/L) and hyperglycemia (> 10 mmol/L) occurred in 18% and 36% from the FO and UFO groups, respectively. Glucose-to-lactate ratio on day 1 was the strongest predictor of unfavorable metabolic outcome (OR 3.27 [Formula: see text] 1.81, p = 0.032) when adjusted for other clinical and metabolic variables, including Sarnat score.

CONCLUSION

Glucose-to-lactate ratio on day 1 may represent a new risk marker for infants with HIE undergoing TH.

WHAT IS KNOWN

• Glucose and lactate are key metabolic fuels during neonatal hypoglycemia. This suggests that their concentrations may influence the neurodevelopmental outcome of neonates experiencing hypoxic-hischemic encephalopathy (HIE).

WHAT IS NEW

• We describe the relative availbility of glucose and lactate before and during theraputic hypothermia in neonates with HIE.

Outcome prediction in newborn infants: Past, present, and future

The perinatal and neonatal periods are the periods of considerable organ development and maturation. Perinatal and neonatal illnesses can result in mortality and morbidities that burden families and the healthcare system. Outcome prediction is essential for informing perinatal and intensive care management, prognosis, and post-discharge interventions. The Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) research databases include hospital and neurodevelopment follow-up outcomes of infants with various underlying diseases and conditions receiving intensive care, providing a unique opportunity to assess outcome risk prediction. The NRN has developed outcome risk prediction tools for use in infants with various diseases and conditions that allow data-driven, transparent discussions to inform family-focused communications and clinical management. This review presents the published neonatal outcome risk prediction research from the NRN, their present clinical utility, and possible future directions for advanced individualized risk prediction.

Predictive Ability of 10-Minute Apgar Scores for Mortality and Neurodevelopmental Disability

OBJECTIVE

To test the hypothesis that an Apgar score at 10 minutes is independently predictive for death or moderate or severe disability.

METHODS

A secondary analysis of the Optimizing Cooling Trial (NCT01192776) including 347 infants with ≥36 weeks' gestational age at birth and hypoxic-ischemic encephalopathy and 18- to 22-month outcomes from 18 US centers in the National Institute of Child Health and Human Development Neonatal Research Network. The primary outcome was the composite of death or moderate/severe disability at 18 to 22 months of age. Generalized estimating equation models were used to examine the relationship between Apgar scores and outcomes, controlling for center, hypothermia treatment, and severity of hypoxic-ischemic encephalopathy (HIE). Classification and regression tree analyses were conducted to identify combinations of variables available during resuscitation that were most predictive for the composite outcome and death.

RESULTS

The study revealed that 50% (13 of 26) of infants with a 10-minute Apgar score of 0 survived; 46% (6 of 13) had no disability, 16% (2 of 13) had mild disability, and 38% (5 of 13) had moderate or severe disability. The 10-minute Apgar score of 0 was independently associated with death or moderate or severe disability (adjusted relative risk = 1.72, 95% confidence interval 1.11-2.68, P value = .016), but the area under the curve analysis (AUC) was low (AUC = 0.56). The predictive accuracy improved when the 10-minute Apgar score was combined with other risk variables available during resuscitation by using a classification and regression tree analysis (AUC = 0.66).

CONCLUSIONS

A 10-minute Apgar score of 0 alone does not predict the risk of death or moderate or severe disability well. The current study provides evidence in support of the 2020 American Heart Association/International Liaison Committee on Resuscitation recommendation for continuing resuscitative efforts for infants who need cardiopulmonary resuscitation at 10 minutes after birth.

Blanket temperature during therapeutic hypothermia and outcomes in hypoxic ischemic encephalopathy

OBJECTIVE

Determine whether blanket temperatures during therapeutic hypothermia (TH) are associated with 18-22 month outcomes for infants with hypoxic ischemic encephalopathy (HIE).

STUDY DESIGN

Retrospective cohort study of 181 infants with HIE who received TH in two randomized trials within the Neonatal Research Network. We defined summative blanket temperature constructs and evaluated for association with a primary composite outcome of death or moderate/ severe disability at 18-22 months.

RESULTS

Each 0.5 °C above 33.5 °C in the mean of the highest quartile blanket temperature was associated with a 52% increase in the adjusted odds of death/ disability (aOR 1.52, 95% CI 1.09-2.11). Having >8 consecutive blanket temperatures above 33.5 °C rendered an aOR of death/disability of 5.04 in the first 24 h (95% CI 1.54-16.6) and 6.92 in the first 48 h (95% CI 2.20-21.8) of TH.

CONCLUSIONS

Higher blanket temperature during TH may be an early, clinically useful biomarker of HIE outcome.

Association of Total Sarnat Score with brain injury and neurodevelopmental outcomes after neonatal encephalopathy

We examined the association of Total Sarnat Score (TSS) with brain injury on neonatal magnetic resonance (MR) and adverse neurodevelopmental outcome (NDO) (death or moderate or severe disability) at 2 years of age in 145 infants undergoing therapeutic hypothermia for neonatal encephalopathy. TSS was associated with basal ganglia/thalamic injury on conventional MR (p=0.03) and thalamic N-acetyl aspartate on MR spectroscopy (R²=0.16, p=0.004) at 2 weeks of age, and Bayley Composite Cognitive (R²=0.18, p=0.01), Motor (R²=0.15, p=0.02) and Language (R²=0.11, p=0.01) Scores at 2 years of age after adjustment for seizures at the time of neurological assessment. The accuracy of TSS (area under the curve (AUC)=0.71) for predicting adverse NDO was similar to the modified Sarnat staging (AUC=0.72). TSS of >12 within 6 hours of birth indicated high risk of adverse NDO, while TSS of <4 indicated intact survival and was reassuring of a good outcome among cooled infants.

Blood gas measures as predictors for neonatal encephalopathy severity

OBJECTIVE

To correlate arterial umbilical cord gas (aUCG) and infant blood gas with severity of neurological injury.

STUDY DESIGN

Retrospective single-site study of infants evaluated for therapeutic hypothermia. Clinical neurological examination and a validated MRI scoring system were used to assess injury severity.

RESULTS

Sixty-eight infants were included. aUCG base deficit (BD) and lactate correlated with infant blood gas counterparts (r = 0.43 and r = 0.56, respectively). aUCG and infant pH did not correlate. Infant blood gas lactate (R_ADJ² = 0.40), infant BD (R_ADJ² = 0.26), infant pH (R_ADJ² = 0.17), aUCG base deficit (R_ADJ² = 0.08), and aUCG lactate (R_ADJ² = 0.11) were associated with clinical neurological examination severity. aUCG and infant blood gas measures were not correlated with MRI score.

CONCLUSION

Metabolic measures from initial infant blood gases were most associated with the clinical neurological examination severity and can be used to evaluate hypoxic-ischemic cerebral injury risk.

Mild Neonatal Acidemia is Associated with Neonatal Morbidity at Term

OBJECTIVE

The aim of this study is to determine the association between mild acidemia (umbilical artery [UA] pH: 7.11-7.19) and neonatal morbidity in neonates at term.

STUDY DESIGN

This is a secondary analysis of a prospective cohort of women admitted for labor at ≥37 weeks of gestation within a single institution from 2010 to 2015. Universal umbilical cord blood gas assessment was performed and validated. A composite neonatal morbidity index was created including respiratory distress, mechanical ventilation, meconium aspiration syndrome, suspected or confirmed sepsis, hypoxic-ischemic encephalopathy, need for therapeutic hypothermia, seizures and death. The cohort was stratified by UA pH into normal (≥7.20), mild acidemia (7.11-7.19), acidemia (7.00-7.10), and severe acidemia (≤7.00). A subanalysis was also performed where neonates with UA pH between 7.11 and 7.19 were further stratified into two groups (7.11-7.14 and 7.15-7.19) to determine if mildly acidotic infants at the lower end of the pH range were at increased risk of morbidity. Multivariable logistic regression was used to estimate the association between UA pH and neonatal morbidity.

RESULTS

Among 6,341 participants, 614 (9.7%) had mild acidemia. These infants were more likely to experience morbidity compared with those with normal UA pH (adjusted odds ratio [aOR]: 2.14; [1.68-2.73]). Among neonates with mild acidemia, UA pH 7.11 to 7.14 was associated with increased risk of composite neonatal morbidity (aOR: 3.02; [1.89-4.82]), as well as respiratory distress and suspected or confirmed sepsis when compared with UA pH 7.15 to 7.19.

CONCLUSION

These data demonstrate that term neonates with mild acidemia at birth are at higher odds for short-term morbidity compared with neonates with normal UA pH. Furthermore, among neonates with mild acidemia, those with lower UA pH had worse neonatal outcomes than those with higher UA pH. This suggests that closer evaluation of neonates with UA pH higher than traditionally used could allow for earlier detection of morbidity and possible intervention.

KEY POINTS

· Neonates with mild acidemia (umbilical artery [UA] pH: 7.11-7.19) demonstrated an increased risk of composite morbidity compared with those with normal UA pH (≥7.20).. · Among neonates with mild acidemia, those with lower UA pH (7.11-7.14) had a greater risk of morbidity compared with those with higher UA pH (7.15-7.19), suggesting a progression of risk of morbidity as UA pH decreases.. · The majority of prior research has focused on severe acidemia (UA pH ≤ 7.00) using outcomes of severe neurologic morbidity and mortality. These data suggest that an increased risk of morbidity exists at higher pH values when more proximal and less severe outcomes are included, such as respiratory distress and neonatal sepsis..

Thermal Index for early non-invasive assessment of brain injury in newborns treated with therapeutic hypothermia: preliminary report

Perinatal asphyxia (PA) is the 3rd most common cause of neonatal death and one of the most common causes of severe neurological impairments in children. Current tools and measurements mainly based on the analysis of clinical evaluation and laboratory and electrophysiological tests do not give consistent data allowing to predict the severity of hypoxic-ischemic encephalopathy (HIE) until a magnetic resonance imaging (MRI) score is performed. The aim of this work is to evaluate the usefulness of the new index, called Thermal Index (TI) in the assessment of the degree of brain damage in newborns in the course of therapeutic hypothermia (TH) due to PA. This was a prospective, observational, pilot study which did not require any changes in the applicable procedures. Analysis has been applied to six newborn babies treated with TH in Neonatal/Paediatric ICU in University Hospital in Opole in 2018 due to PA. They all met criteria for TH according to the current recommendations. Brain MRI was performed after the end of TH when the children were brought back to normal temperature, with the use of a 1.5 T scanner, using T1-, T2-weighted images, fluid-attenuated inversion recovery (FLAIR), inversion recovery (IR), susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI). The images were assessed using MRI score according to the scoring system proposed by Weeke et al. The Thermal Index assessing endogenous heat production was calculated according to the formula proposed in this paper. A high, statistically significant positive correlation was found between MRI scores and TI values (0.98; p = 0.0003) in the 1st hour of therapy. High correlation with MRI assessment, the non-invasiveness of measurements and the availability of results within the first few hours of treatment, allow authors to propose the Thermal Index as a tool for early evaluating of the brain injury in newborns treated with TH. Further research is required to confirm the usefulness of the proposed method.

Does Severity of Brain Injury on Magnetic Resonance Imaging Predict Short-Term Outcome in Neonates Who Received Therapeutic Hypothermia?

OBJECTIVE

 The National Institute of Child Health and Human Development (NICHD) magnetic resonance imaging (MRI) pattern of brain injury is a known biomarker of childhood outcome following therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy (HIE). However, usefulness of this classification has not been evaluated to predict short-term outcomes. The study aimed to test the hypothesis that infants with NICHD MRI pattern of severe hypoxic-ischemic brain injury will be sicker with more severe asphyxia-induced multiorgan dysfunction resulting in prolonged length of stay (LOS) following therapeutic hypothermia. We also evaluated the role of other risk factors which may prolong LOS.

STUDY DESIGN

 We retrospectively reviewed the medical records of 71 consecutively cooled neonates to examine the ability of MRI patterns of brain injury to predict the LOS. A neuroradiologist masked to outcomes classified the patterns of brain injury on MRI as per NICHD. Pattern 2A (basal ganglia thalamic, internal capsule, or watershed infarction), 2B (2A with cerebral lesions), and 3 (hemispheric devastation) of brain injury was deemed "severe injury."

RESULTS

 Out of 71 infants, 59 surviving infants had both MRI and LOS data. LOS was higher for infants who had Apgar's score of ≤5 at 10 minutes, severe HIE, seizures, coagulopathy, or needed vasopressors or inhaled nitric oxide, or had persistent feeding difficulty, or remained intubated following cooling. However, median LOS did not differ between the infants with and without MRI pattern of severe injury (15 days, interquartile range [IQR]: 9-28 vs. 12 days, IQR: 10-20; p = 0.4294). On multivariate linear regression analysis, only persistent feeding difficulty (β coefficient = 11, p = 0.001; or LOS = 11 days longer if had feeding difficulty) and ventilator days (β coefficient 1.7, p < 0.001; or LOS increased 1.7 times for each day of ventilator support) but not the severity of brain injury predicted LOS.

CONCLUSION

 Unlike neurodevelopmental outcome, LOS is not related to severity of brain injury as defined by the NICHD.

KEY POINTS

· The NICHD pattern of brain injury on MRI predicts neurodevelopmental outcome following hypothermia treatment for neonatal HIE.. · LOS did not differ between the infants with and without MRI patterns of severe injury.. · The severity of brain injury as defined by the NICHD was not predictive of the LOS following therapeutic hypothermia..

The safety of passive hypothermia during assessment for hypoxic ischaemic encephalopathy

INTRODUCTION

Hypoxic ischaemic encephalopathy (HIE) is poorly predicted by markers of hypoxic ischaemic (HI) delivery. Repeated examination of infants with HI markers facilitates diagnostic certainty of HIE severity. When infants with HIE are nursed at incubator ambient air-temperature set to achieve normothermia, there is sometimes associated hyperthermia, a predictor of poor outcome. An alternative is to nurse infants without external heat (passive hypothermia, PH). We report a retrospective cohort-study to determine the safety of PH during the assessment of infant eligibility for therapeutic hypothermia (TH).

METHODS

Inborn infants of gestational age ≥36 weeks, less than 6 h of age, with evidence of HI delivery were admitted for assessment for HIE. Infants were nursed undressed in an incubator treated with PH and underwent serial neurological examinations to determine eligibility for TH. Body temperature was monitored but no targeted temperature was set. Safety outcomes during PH were: minimum and maximum temperatures, minimum and maximum glucose recordings, time to onset of TH, platelet count, maximum and minimum blood glucose concentration.

RESULTS

26 infants with median gestational age of 39 weeks, median birth weight of 3.30 kg underwent PH for a median duration of 4 h 19 min. During PH the median minimum and maximum temperatures recorded were 35.9 °C and 36.7 °C, the median minimum glucose was 4.6 mmol/L. Fourteen infants were eligible for TH and target temperature was achieved at median age of 4 h.

CONCLUSION

PH is not associated with adverse safety outcomes and without delaying achieving TH target-temperature.

Early Determination of Prognosis in Neonatal Moderate or Severe Hypoxic-Ischemic Encephalopathy

BACKGROUND AND OBJECTIVES

Early determination of prognosis is important in neonates with hypoxic-ischemic encephalopathy (HIE). Our objective was to test scoring systems developed earlier (original scoring system) and develop new prognostic models.

METHODS

Secondary analysis of data from the multicenter randomized controlled trial of longer, deeper, or usual care cooling in neonatal HIE (NCT01192776) that enrolled 364 neonates diagnosed with moderate or severe HIE. The primary outcome was death or moderate or severe disability at 18 to 22 months, and secondary outcome was death during initial hospitalization. Testing of early neurologic clinical examination (<6 hours of age) and the original scoring system for prognostic ability was done, followed by development of new scoring systems and classification and regression tree (CART) models by using early clinical variables (<6 hours of age).

RESULTS

For death or disability, the original scoring system correctly classified 75% (95% confidence interval: 69%-81%), whereas the new scoring system correctly classified 78% (73%-82%), and the CART model correctly classified 76% (72%-81%). Early neurologic clinical examination also had a correct classification rate of 76% (71%-80%). Depth and duration of cooling did not affect prediction. Only a few components of the early neurologic examination were associated with poor outcome. For death, the original scoring system correctly classified 72% (66%-77%), the new scoring system 68% (63%-72%), the new CART model 87% (83%-90%), and early neurologic evaluation 81% (77%-85%).

CONCLUSIONS

The 3 models (scoring system, CART, and early neurologic evaluation) were comparable in predicting death or disability. For in-hospital death, CART models were superior to scoring systems and early neurologic examination.

A Decision-Tree Approach to Assist in Forecasting the Outcomes of the Neonatal Brain Injury

Neonatal brain injury or neonatal encephalopathy (NE) is a significant morbidity and mortality factor in preterm and full-term newborns. NE has an incidence in the range of 2.5 to 3.5 per 1000 live births carrying a considerable burden for neurological outcomes such as epilepsy, cerebral palsy, cognitive impairments, and hydrocephaly. Many scoring systems based on different risk factor combinations in regression models have been proposed to predict abnormal outcomes. Birthweight, gestational age, Apgar scores, pH, ultrasound and MRI biomarkers, seizures onset, EEG pattern, and seizure duration were the most referred predictors in the literature. Our study proposes a decision-tree approach based on clinical risk factors for abnormal outcomes in newborns with the neurological syndrome to assist in neonatal encephalopathy prognosis as a complementary tool to the acknowledged scoring systems. We retrospectively studied 188 newborns with associated encephalopathy and seizures in the perinatal period. Etiology and abnormal outcomes were assessed through correlations with the risk factors. We computed mean, median, odds ratios values for birth weight, gestational age, 1-min Apgar Score, 5-min Apgar score, seizures onset, and seizures duration monitoring, applying standard statistical methods first. Subsequently, CART (classification and regression trees) and cluster analysis were employed, further adjusting the medians. Out of 188 cases, 84 were associated to abnormal outcomes. The hierarchy on etiology frequencies was dominated by cerebrovascular impairments, metabolic anomalies, and infections. Both preterms and full-terms at risk were bundled in specific categories defined as high-risk 75-100%, intermediate risk 52.9%, and low risk 0-25% after CART algorithm implementation. Cluster analysis illustrated the median values, profiling at a glance the preterm model in high-risk groups and a full-term model in the inter-mediate-risk category. Our study illustrates that, in addition to standard statistics methodologies, decision-tree approaches could provide a first-step tool for the prognosis of the abnormal outcome in newborns with encephalopathy.

Brainstem hypoxic-ischemic lesions on MRI in infants treated with therapeutic cooling: effects on the length of stay and mortality

OBJECTIVE

To test the hypothesis that brainstem hypoxic-ischemic injury on magnetic resonance imaging (MRI) would be independently associated with short-term outcomes in cooled asphyxiated infants.

METHODS

A total of 90 consecutively cooled asphyxiated infants who survived to have brain MRI were reviewed. A neuroradiologist who was masked to outcomes evaluated MRI images for brainstem involvement. Outcomes were mortality and length of stay.

RESULTS

Brainstem lesions were present on post-cooling brain MRI in 20 of the 90 infants (22%). Overall, four infants died before discharge, and all four had brainstem involvement. The infants with brainstem involvement had longer hospital stay (29 days, IQR 20-47 versus 16 days, IQR 10-26; P = 0.0001), compared to infants without brainstem lesions (n = 70); and upon multivariate analysis, brainstem involvement remained independently associated with prolonged hospital stay (β = 12.4, P = 0.001).

CONCLUSION

This study demonstrates the importance of recognizing brainstem injury for the prediction of short-term outcomes in cooled asphyxiated infants.

Is Uterine Myomectomy a Real Contraindication to Vaginal Delivery? Results from a Prospective Study

OBJECTIVES

The main goal of our research was to explore correlations between a history of uterine myomectomy and maternal-fetal outcomes, throughout a comparison between vaginal deliveries in patients with or without a history of uterine myoma excision.

MATERIALS AND METHODS

A prospective study was carried out at two tertiary care hospitals between January 2019 and January 2020. Women were assigned into two groups according to the history of laparoscopic or laparotomic myomectomy (Group 1) or without myomectomy (Group 2).

RESULTS

80 women successfully delivered after myomectomy. Pregnancies with previous laparoscopic or laparotomic myomectomy were associated with a minor rate of spontaneous labor onset (RR 1.17; 95% CI 1.04 - 1.31) and with an increased rate of emergency cesarean section (RR 1.22; 95% CI 1.09 - 1.36). Moreover, myomectomy group had a significant number of indications to emergency cesarean section correlated to suspected uterine rupture (RR 1.19; 95% CI 1.02-1.39). There were no uterine ruptures or neonatal deaths recorded. First stage of labor was longer in the myomectomy group (316 vs 204 mins, p = 0.01). No differences in the rates of the prolonged first and second stage of labor, postpartum hemorrhage and vaginal laceration, and no neonatal adverse outcomes were found between groups.

CONCLUSIONS

Pregnancies after myomectomy might be associated with an elevated rate of emergency cesarean section only due to a higher percentage of suspected uterine rupture, without a real hazard of adverse obstetric or neonatal outcomes.

Correlation Between Heart Rate Characteristic Index Score and Severity of Brain Injury in Neonates With Hypoxic-Ischemic Encephalopathy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) remains devastating for neonates despite widespread treatment with therapeutic hypothermia (TH). The heart rate characteristic (HRC) index score, a measure of heart rate variability, could prove useful in the management of neonates with HIE as new therapies emerge or when withdrawal-of-support decisions are being considered.

PURPOSE

The main purpose was to describe correlation between HRC index scores and brain magnetic resonance imaging (MRI) severity of injury for neonates with HIE.

METHODS/ANALYSIS

Low/high HRC index scores retrieved at initiation of TH (baseline), 24, 48, 72, and 96 hours, brain MRI severity of injury, and National Institute of Child Health and Human Development Death/Disability and Death scores were collected and analyzed retrospectively. Independent t tests and linear regression were used to examine relationships for each outcome measure.

RESULTS

Twenty-seven neonates were stratified into 2 groups: noninjury (n = 11) and injury (n = 16). Statistically significant relationships were observed. Strikingly, mean low HRC index score for the noninjury group ranged between 0.37 and 0.65 and was between 0.61 and 0.86 for the injury group. Mean high HRC index score for the noninjury group ranged between 0.66 and 1.02 and was between 1.04 and 1.41 for the injury group.

IMPLICATIONS FOR PRACTICE

HRC index score may be a useful guide in the future management of neonates with HIE.

IMPLICATIONS FOR RESEARCH

This study established correlations between HRC index and MRI injury scores in neonates treated with TH. Further research is warranted to establish important relationships between brain injury and HRC index scores before this tool can be used clinically for this purpose.

Cerebral Pulsed Arterial Spin Labeling Perfusion Weighted Imaging Predicts Language and Motor Outcomes in Neonatal Hypoxic-Ischemic Encephalopathy

Rationale and Objectives: To compare cerebral pulsed arterial spin labeling (PASL) perfusion among controls, hypoxic ischemic encephalopathy (HIE) neonates with normal conventional MRI(HIE/MRI⊕), and HIE neonates with abnormal conventional MRI(HIE/MRI⊖). To create a predictive machine learning model of neurodevelopmental outcomes using cerebral PASL perfusion. Materials and Methods: A total of 73 full-term neonates were evaluated. The cerebral perfusion values were compared by permutation test to identify brain regions with significant perfusion changes among 18 controls, 40 HIE/MRI⊖ patients, and 15 HIE/MRI⊕ patients. A machine learning model was developed to predict neurodevelopmental outcomes using the averaged perfusion in those identified brain regions. Results: Significantly decreased PASL perfusion in HIE/MRI⊖ group, when compared with controls, were found in the anterior corona radiata, caudate, superior frontal gyrus, precentral gyrus. Both significantly increased and decreased cerebral perfusion changes were detected in HIE/MRI⊕ group, when compared with HIE/MRI⊖ group. There were no significant perfusion differences in the cerebellum, brainstem and deep structures of thalamus, putamen, and globus pallidus among the three groups. The machine learning model demonstrated significant correlation (p < 0.05) in predicting language(r = 0.48) and motor(r = 0.57) outcomes in HIE/MRI⊖ patients, and predicting language(r = 0.76), and motor(r = 0.53) outcomes in an additional group combining HIE/MRI⊖ and HIE/MRI⊕. Conclusion: Perfusion MRI can play an essential role in detecting HIE regardless of findings on conventional MRI and predicting language and motor outcomes in HIE survivors. The perfusion changes may also reveal important insights into the reperfusion response and intrinsic autoregulatory mechanisms. Our results suggest that perfusion imaging may be a useful adjunct to conventional MRI in the evaluation of HIE in clinical practice.

Maternal and neonatal complications of fetal macrosomia: cohort study

OBJECTIVE

To estimate the risks of maternal and neonatal complications in pregnancies with macrosomia.

METHODS

This was a retrospective cohort study conducted at a large maternity unit in the UK between January 2009 and December 2016. The incidence of maternal and neonatal complications in pregnancies with macrosomia, defined as birth weight (BW) > 4000 g, and in those with severe macrosomia, defined as BW > 4500 g, was compared with that in pregnancies with normal BW (2500-4000 g). Regression analysis was performed to determine odds ratios (ORs) for complications in macrosomic pregnancies compared to those with normal BW.

RESULTS

The study population of 35 548 pregnancies included 4522 (12.7%) with macrosomia, of which 643 (1.8%) had severe macrosomia, and 31 026 (87.3%) with normal BW. In the macrosomia group, the adjusted OR was 3.1 (95% CI, 2.6-3.6) for Cesarean section for failure to progress, 2.4 (95% CI, 2.0-3.0) for severe postpartum hemorrhage, 2.3 (95% CI, 1.9-2.8) for obstetric anal sphincter injury, 10.4 (95% CI, 8.6-12.6) for shoulder dystocia, 28.5 (95% CI, 8.9-90.7) for obstetric brachial plexus injury, 32.3 (95% CI, 3.8-278.2) for birth fractures and 4.4 (95% CI, 2.2-8.8) for hypoxic-ischemic encephalopathy. The respective values in pregnancies with severe macrosomia were 4.3 (95% CI, 3.1-6.1), 2.9 (95% CI, 1.9-4.4), 3.1 (95% CI, 1.9-5.1), 28.7 (95% CI, 20.8-39.8), 73.9 (95% CI, 15.1-363.2), 87.2 (95% CI, 7.7-985.0) and 13.8 (95% CI, 5.2-36.8).

CONCLUSION

Macrosomia is associated with serious adverse perinatal outcomes. This study provides accurate estimates of risks to aid in pregnancy management. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Effect of carbamylated erythropoietin on neuronal apoptosis in fetal rats during intrauterine hypoxic-ischemic encephalopathy

Background

Hypoxic-ischemic encephalopathy (HIE) is a common disease that occurs during the perinatal period. The primary cause of neonatal HIE is related to fetal intrauterine anoxia. Carbamylated erythropoietin (CEPO), a derivative of erythropoietin (EPO), does not exert any erythropoietic effect; however, the neuroprotective effects resemble those of EPO. Previous studies have shown the potential benefits of CEPO on the central nervous system. The present study aimed to investigate the role of CEPO in neuronal apoptosis during intrauterine HIE and the underlying mechanisms.

Results

To validate our hypothesis, we established an intrauterine HIE model by occluding the bilateral utero-ovarian arteries of pregnant Sprague–Dawley rats. Compared to the I/R group, neuronal apoptosis in the CEPO group was significantly lower at 4, 12, 24, and 48 h (P < 0.05). CEPO significantly inhibited CC3 expression (P < 0.05) during the early-stages after ischemia–reperfusion (0.5, 4, 8, 12 and 24 h), upregulated Bcl-2 expression, and downregulated Bax expression at 4, 8, 12, and 24 h (P < 0.05).

Conclusions

Carbamylated erythropoietin pretreatment inhibited the expression of proapoptotic protein CC3 in brain and regulated the Bcl-2/Bax ratio, resulting in reduced neuronal apoptosis and thus resulting in a protective effect on intrauterine HIE.

Perinatal prediction model for severe intraventricular hemorrhage and the effect of early postnatal acidosis

PURPOSE

Severe acidosis is one of the strongest predictors of neurologic outcomes in full-term infants with suspected hypoxic-ischemic encephalopathy. However, the relative importance of acidosis as a predictor of outcomes in preterm infants is much less clear. The goals of the present study were to examine the association between postnatal acidosis and severe intraventricular hemorrhage (IVH) and to establish a new score model including acid-base status after birth for predicting the risk of this morbidity.

METHODS

The study sample was very low birth weight (VLBW) infants in the Korean Neonatal Network (KNN) cohort registry, collected prospectively from January 2013 to December 2014. Infants with blood pH and base deficit (BD) values collected within the first hour after birth, and documentation of severe IVH, were included. Multivariate stepwise logistic regression analysis was used to determine the contribution of postnatal acidosis to predicting severe IVH in VLBW infants. In addition, a prediction model was developed.

RESULTS

Data from 2518 VLBW infants were analyzed. Infants with postnatal acidosis had a higher incidence of severe IVH. The clinical model plus blood BD values improved predictive performance, compared with models using only perinatal data or blood pH.

CONCLUSIONS

A prediction model for severe IVH was developed using the KNN registry of VLBW infants. Immediate postnatal acidosis, defined based on blood BD, was associated with a higher-risk-adjusted incidence of severe IVH.

Survey of ECMO practices for infants with hypoxic ischemic encephalopathy

OBJECTIVE

Historically, some physicians are reluctant to offer extracorporeal membrane oxygenation (ECMO) to infants with neonatal encephalopathy. This study describes how ECMO practices have changed since the development of therapeutic hypothermia (TH) for neonatal encephalopathy.

STUDY DESIGN

A 22-question electronic survey was sent to neonatal medical directors and ECMO directors in the USA and Canada. Participants were queried on TH and ECMO practices and if they would offer ECMO given certain clinical factors; confidential responses were compared with a similar survey conducted in 2008.

RESULT

A total of 356 physicians were invited to participate, and the response rate was 25%. Seventy-two percent had initiated or referred for ECMO during cooling therapy. Compared with the 2008 survey, participants were more likely to offer ECMO for moderate and severe encephalopathy. Ninety-four percent offer hypothermia for neonatal encephalopathy, but only 24% have written ECMO criteria for such patients. Neonatologists were more likely than non-neonatologists to offer ECMO for mild and moderate encephalopathy.

CONCLUSION

ECMO use with neonatal encephalopathy has increased since TH has become standard care. Wide variability in practice remains with important differences between neonatologists and non-neonatologists.

Predicting the need for home gavage or g-tube feeds in asphyxiated neonates treated with therapeutic hypothermia

BACKGROUND

Asphyxiated infants treated with therapeutic cooling can have persistent oral feeding difficulty because of involvement of neural pathways in the brainstem, cortex, and basal ganglia. The goal is to predict the composite adverse outcome of death or persistent oral feeding difficulty using precooling/cooling attributes, and the severity and distribution of hypoxic-ischemic lesions, especially brainstem lesions on post-cooling brain magnetic resonance imaging (MRI).

METHODS

Retrospective review of 86 asphyxiated infants cooled from January 2006 to August 2014. Persistent feeding difficulty was defined as needing feeding support (gastrostomy tube (g-tube) or home gavage feeds) after discharge. Clinical and laboratory risk factors, and the brain MRI abnormalities including the presence of brainstem lesions were compared between infants with and without adverse outcome using univariate analysis. Significant variables were then analyzed in a stepwise logistic regression (LR) model.

RESULTS

Infants with adverse outcome (n = 31, 4 died pre-discharge) had longer hospital stay (26 days, interquartile range (IQR) 19-43 vs. 13 days, IQR 9-20; p < 0.01) and reached goal enteral feeds (oral/gavage) later (11 days vs. 8 days, p < 0.01) compared to 55 infants discharged on full oral feeds. The former infants were more likely to have cord pH ≤ 7.15, severely abnormal neurological examination, bleeding diathesis, continued need for ventilation, and positive MRI findings including brainstem lesions. In LR analysis, brainstem lesions on MRI (p = 0.00, odds ratio 19, 95% confidence interval 4-85) was independently associated with the adverse outcome.

CONCLUSIONS

Brainstem involvement on post-cooling brain MRI was predictive of adverse outcome. Early identification of these infants may facilitate discussion of home feeding plans between clinicians and parents earlier, thereby potentially reducing the length of hospital stay.

Prediction of Future Epilepsy in Neonates With Hypoxic-Ischemic Encephalopathy Who Received Selective Head Cooling

Epilepsy outcomes after therapeutic hypothermia for neonates with hypoxic-ischemic encephalopathy are understudied. The authors used multivariable logistic regression to predict epilepsy in neonates after selective head cooling. Sensitivity analyses used magnetic resonance imaging (MRI) and electroencephalogram (EEG) interpretations by different clinicians. Fifty neonates had 2-year follow-up. Nine developed epilepsy. Predictors included pH ≤6.8 on day of birth (adjusted odds ratio [OR] 19 [95% confidence interval (CI) 1-371]), burst suppression on EEG on day 4 (8.2 [1.3-59]), and MRI deep gray matter injury (OR 33 [2.4-460]). These factors stratify neonates into low (0-1 factors; 3% [0%-14%] risk), medium (2 factors; 56% [21%-86%] risk), and high-risk groups (3 factors; 100% [29%-100%] risk) for epilepsy. The stratification was robust to varying clinical interpretations of the MRI and EEG. Neonates with hypoxic-ischemic encephalopathy who undergo selective head cooling appear at risk of epilepsy if they have 2 to 3 identified factors. If validated, this rule may help counsel families and identify children for close clinical follow-up.

Gestational age and birthweight for risk assessment of neurodevelopmental impairment or death in extremely preterm infants

BACKGROUND

The risk of poor outcomes in preterm infants is primarily determined by birthweight (BW) and gestational age (GA). It is not known whether BW is a better outcome predictor than GA.

OBJECTIVE

To test whether BW is better than GA (measured in days, rather than completed weeks) for prediction of neurodevelopmental impairment (NDI) and death.

DESIGN/METHODS

Extremely preterm infants born at the National Institute of Child Health and Human Development (NICHD) Neonatal Research Network centres between 1998 and 2009 were studied. For the unadjusted analysis, the associations of GA (in days based on best obstetrical estimate) and BW (in grams) with NDI or death were compared using area under the curve (AUC). Adjusted analyses were performed using birth year, sex, race, antenatal steroids, singleton birth, pre-eclampsia, Apgar score at 5 min and small for GA as covariates.

RESULTS

10 652 preterm infants (89%) had outcome data at 18-22 months' corrected age. The mean BW was 678 g (SD: 155) and the mean GA was 173 days (SD: 10) or 24^5/7 weeks (SD: 1^3/7). The AUC for NDI or death was 80% with BW and 79% with GA (p=0.82). Unadjusted and adjusted analyses did not differ. NDI or death rates decreased with increasing GA through 26 weeks (estimated risk reduction with each additional day of gestation: 2.2%).

CONCLUSION

Both BW in grams and GA in days are good predictors of NDI and death in a preterm population selected on the basis of reliable GA.

TRIAL REGISTRATION NUMBER

NCT00009633.

Hypothermia for neonatal hypoxic-ischemic encephalopathy: NICHD Neonatal Research Network contribution to the field

In this article, we summarize the NICHD Neonatal Research Network (NRN) trial of whole-body hypothermia for neonates with hypoxic-ischemic encephalopathy in relation to other randomized controlled trials (RCTs) of hypothermia neuroprotection. We describe the NRN secondary studies that have been published in the past 10 years evaluating clinical, genetic, biochemical, and imaging biomarkers of outcome.

In vivo longitudinal proton magnetic resonance spectroscopy on neonatal hypoxic-ischemic rat brain injury: Neuroprotective effects of acetyl-L-carnitine

PURPOSE

This study evaluated the longitudinal metabolic alterations after neonatal hypoxia-ischemia (HI) in rats and tested the neuroprotective effect of acetyl-L-carnitine (ALCAR) using in vivo proton short-TE Point-RESolved Spectroscopy method.

METHODS

Rice-Vannucci model was used on 7-day-old Sprague-Dawley rats. Data were acquired from contralateral and ipsilateral cortex and hippocampus, respectively at 4 time points (24-h, 72-h, 7-days, 28-days) post-HI. The effect of subcutaneous administration of ALCAR (100 mg/kg) immediately after HI, at 4-h, 24-h, and 48-h post-HI was determined.

RESULTS

Significant reductions in glutathione (P < 0.005), myo-inositol (P < 0.002), taurine (P < 0.001), and total creatine (P < 0.005) were observed at 24-h postinjury compared with the control group in the ipsilateral hippocampus of the HI rat pups. ALCAR-treated-HI rats had lower levels of lactate and maintained total creatine at 24-h and had smaller lesion size compared with the HI only rats.

CONCLUSION

Severe oxidative, osmotic stress, impaired phosphorylation, and a preference for anaerobic glycolysis were found in the ipsilateral hippocampus in the HI pups at 24-h postinjury. ALCAR appeared to have a neuroprotective effect if administered early after HI by serving as an energy substrate and promote oxidative cerebral energy producing and minimize anaerobic glycolysis.

Cognitive Dysfunction and Hippocampal Damage Induced by Hypoxic-Ischemic Brain Injury and Prolonged Febrile Convulsions in Immature Rats

Objective

Perinatal hypoxic-ischemic encephalopathy (HIE) and prolonged febrile seizures (pFS) are common neurologic problems that occur during childhood. However, there is insufficient evidence from experimental studies to conclude that pFS directly induces hippocampal injury. We studied cognitive function and histological changes in a rat model and investigated which among pFS, HIE, or a dual pathologic effect is most detrimental to the health of children.

Methods

A rat model of HIE at postnatal day (PD) 7 and a pFS model at PD10 were used. Behavioral and cognitive functions were investigated by means of weekly open field tests from postnatal week (PW) 3 to PW7, and by daily testing with the Morris water maze test at PW8. Pathological changes in the hippocampus were observed in the control, pFS, HIE, and HIE+pFS groups at PW9.

Results

The HIE priming group showed a seizure-prone state. The Morris water maze test revealed a decline in cognitive function in the HIE and HIE+pFS groups compared with the pFS and control groups. Additionally, the HIE and HIE+pFS groups showed significant hippocampal neuronal damage, astrogliosis, and volume loss, after maturation. The pFS alone induced minimal hippocampal neuronal damage without astrogliosis or volume loss.

Conclusion

Our findings suggest that pFS alone causes no considerable memory or behavioral impairment, or cellular change. In contrast, HIE results in lasting memory impairment and neuronal damage, gliosis, and tissue loss. These findings may contribute to the understanding of the developing brain concerning conditions caused by HIE or pFS.

Short-term outcomes after perinatal hypoxic ischemic encephalopathy: a report from the Children's Hospitals Neonatal Consortium HIE focus group

OBJECTIVE

To characterize infants affected with perinatal hypoxic ischemic encephalopathy (HIE) who were referred to regional neonatal intensive care units (NICUs) and their related short-term outcomes.

STUDY DESIGN

This is a descriptive study evaluating the data collected prospectively in the Children's Hospital Neonatal Database, comprised of 27 regional NICUs within their associated children's hospitals. A consecutive sample of 945 referred infants born ⩾36 weeks' gestation with perinatal HIE in the first 3 days of life over approximately 3 years (2010-July 2013) were included. Maternal and infant characteristics are described. Short-term outcomes were evaluated including medical comorbidities, mortality and status of survivors at discharge.

RESULT

High relative frequencies of maternal predisposing conditions, cesarean and operative vaginal deliveries were observed. Low Apgar scores, profound metabolic acidosis, extensive resuscitation in the delivery room, clinical and electroencephalographic (EEG) seizures, abnormal EEG background and brain imaging directly correlated with the severity of HIE. Therapeutic hypothermia was provided to 85% of infants, 15% of whom were classified as having mild HIE. Electrographic seizures were observed in 26% of the infants. Rates of complications and morbidities were similar to those reported in prior clinical trials and overall mortality was 15%.

CONCLUSION

Within this large contemporary cohort of newborns with perinatal HIE, the application of therapeutic hypothermia and associated neurodiagnostic studies appear to have expanded relative to reported clinical trials. Although seizure incidence and mortality were lower compared with those reported in the trials, it is unclear whether this represented improved outcomes or therapeutic drift with the treatment of milder disease.

Innate hypothermia after hypoxic ischaemic delivery

The focus of this review is to collate the literature on the phenomenon of impaired thermal adaptation after hypoxic ischaemic (HI) delivery often culminating in hypothermia. This phenomenon appears different in severity and duration to a spontaneous postnatal fall in temperature observed after normal delivery. The original observation and contemporary descriptions of the temperature response to HI are described and a mechanism of action is proposed that may be utilised as a novel biomarker for HI.

Detecting brain injury in neonatal hypoxic ischemic encephalopathy: closing the gap between experimental and clinical research

Moderate to severe neonatal hypoxic ischemic encephalopathy remains an important cause of infant death and childhood disability. Early and accurate diagnosis of encephalopathy is difficult but critical for timely intervention. Thus, we have utilized a clinically relevant large animal model of asphyxia in-utero, followed by immediate lamb delivery, resuscitation and clinical care over the next 72h for assessment of potential biomarkers of brain injury. In-utero asphyxia was induced in twelve near-term lambs and outcomes compared with seven controls. Asphyxia resulted in bradycardia (97±12beats/min), hypotension (12.1±1mm Hg) and metabolic acidosis (pH6.9±0.02; base-excess -13.8±0.8mmol/l). 72h following asphyxia, cerebrospinal concentrations of malondialdehyde and S100B were elevated 2-fold and 5-fold, respectively, in asphyxic lambs compared to control lambs. Magnetic resonance spectroscopy (MRS) at 72h showed a significant decrease in n-acetyl aspartate: choline ratio in asphyxia lambs compared to that observed at 12h (0.56±0.23 vs. 0.82±0.15, respectively); lactate:choline ratio was not changed over this time. Marked neuropathology was observed in asphyxia lambs with neuronal degeneration in the hippocampus, thalamus, striatum and cortex. Astrogliosis was observed in the hippocampus and thalamus. Early blood markers of metabolic state showed limited predictive value of histological damage at 72h. MRS outcomes at 72h showed a modest but significant correlation with histological evidence of neuronal brain injury (lactate:N-acetyl aspartate ratio in the thalamus r(2)=0.2, p<0.01). MRS at 72h was best able to detect established brain injury, but a combination of biomarkers over multiple phases of injury may be able to assess the evolution of neonatal brain injury.

Perinatal risk factors for severe injury in neonates treated with whole-body hypothermia for encephalopathy

OBJECTIVE

Our objective was to identify perinatal risk factors that are available within 1 hour of birth that are associated with severe brain injury after hypothermia treatment for suspected hypoxic-ischemic encephalopathy.

STUDY DESIGN

One hundred nine neonates at ≥35 weeks' gestation who were admitted from January 2007 to September 2012 with suspected hypoxic-ischemic encephalopathy were treated with whole-body hypothermia; 98 of them (90%) underwent brain magnetic resonance imaging (MRI) at 7-10 days of life. Eight neonates died before brain imaging. Neonates who had severe brain injury, which was defined as death or abnormal MRI results (cases), were compared with surviving neonates with normal MRI (control subjects). Logistic regression models were used to identify risk factors that were predictive of severe injury.

RESULTS

Cases and control subjects did not differ with regard to gestational age, birthweight, mode of delivery, or diagnosis of nonreassuring fetal heart rate before delivery. Cases were significantly (P < .05) more likely to have had an abruption, a cord and neonatal arterial gas level that showed metabolic acidosis, lower platelet counts, lower glucose level, longer time to spontaneous respirations, intubation, chest compressions in the delivery room, and seizures. In multivariable logistic regression, lower initial neonatal arterial pH (P = .004), spontaneous respiration at >30 minutes of life (P = .002), and absence of exposure to oxytocin (P = .033) were associated independently with severe injury with 74.3% sensitivity and 74.4% specificity.

CONCLUSION

Worsening metabolic acidosis at birth, longer time to spontaneous respirations, and lack of exposure to oxytocin correlated with severe brain injury in neonates who were treated with whole-body hypothermia. These risk factors may help quickly identify neonatal candidates for time-sensitive investigational therapies for brain neuroprotection.

Outcomes of extremely low birthweight infants with acidosis at birth

OBJECTIVES

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.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Current status of hypothermia for hypoxemic ischemia of the newborn

This article reviews the pathophysiology of hypoxic-ischemic brain injury, and the impact of hypothermia as neuroprotection in the clinical setting. The results of trials performed in well resourced and mid and low resourced countries is presented. Infant and childhood outcome following hypothermia is provided. Biomarkers of outcome that are clinical, electrophysiological and imaging which will be helpful to clinicians are noted. Management of infants with encephalopathy, including safety of hypothermia is reviewed. The article concludes with knowledge gaps in neuroprotection and the future of hypothermia therapy.

Feasibility of autologous cord blood cells for infants with hypoxic-ischemic encephalopathy

OBJECTIVE

To assess feasibility and safety of providing autologous umbilical cord blood (UCB) cells to neonates with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We enrolled infants in the intensive care nursery who were cooled for HIE and had available UCB in an open-label study of non-cyropreserved autologous volume- and red blood cell-reduced UCB cells (up to 4 doses adjusted for volume and red blood cell content, 1-5 × 10(7) cells/dose). We recorded UCB collection and cell infusion characteristics, and pre- and post-infusion vital signs. As exploratory analyses, we compared cell recipients' hospital outcomes (mortality, oral feeds at discharge) and 1-year survival with Bayley Scales of Infant and Toddler Development, 3rd edition scores ≥85 in 3 domains (cognitive, language, and motor development) with cooled infants who did not have available cells.

RESULTS

Twenty-three infants were cooled and received cells. Median collection and infusion volumes were 36 and 4.3 mL. Vital signs including oxygen saturation were similar before and after infusions in the first 48 postnatal hours. Cell recipients and concurrent cooled infants had similar hospital outcomes. Thirteen of 18 (74%) cell recipients and 19 of 46 (41%) concurrent cooled infants with known 1-year outcomes survived with scores >85.

CONCLUSIONS

Collection, preparation, and infusion of fresh autologous UCB cells for use in infants with HIE is feasible. A randomized double-blind study is needed.

Relationship between acute kidney injury and brain MRI findings in asphyxiated newborns after therapeutic hypothermia

BACKGROUND

We hypothesized that acute kidney injury (AKI) in asphyxiated neonates treated with therapeutic hypothermia would be associated with hypoxic-ischemic lesions on brain magnetic resonance imaging (MRI).

METHODS

Medical records of 88 cooled neonates who had had brain MRI were reviewed. All neonates had serum creatinine assessed before the start of cooling; at 24, 48, and 72 h through cooling; and then on day 5 or 7 of life. A neonatal modification of the Kidney Disease: Improving Global Outcomes guidelines was used to classify AKI. MRI images were evaluated by a neuroradiologist masked to outcomes. Outcome of interest was abnormal brain MRI at 7-10 d of life.

RESULTS

AKI was found in 34 (39%) of 88 neonates, with 15, 7, and 12 fulfilling criteria for stages 1, 2, and 3, respectively. Brain MRI abnormalities related to hypoxia-ischemia were present in 50 (59%) newborns. Abnormal MRI was more frequent in infants from the AKI group (AKI: 25 of 34, 73% vs. no AKI: 25 of 54, 46%; P = 0.012; odds ratio (OR) = 3.2; 95% confidence interval (CI) = 1.3-8.2). Multivariate analysis identified AKI (OR = 2.9; 95% CI = 1.1-7.6) to be independently associated with the primary outcome.

CONCLUSION

AKI is independently associated with the presence of hypoxic-ischemic lesions on postcooling brain MRI.

Outcomes of hypoxic-ischemic encephalopathy in neonates treated with hypothermia

This article examines the evidence regarding mortality and neurodevelopmental outcomes following hypothermia for neonatal hypoxic-ischemic encephalopathy. Data from randomized controlled trials regarding neurodevelopmental outcome at the end point of the major trials, and from 2 of the trials on childhood outcome following hypothermia for neonatal hypoxic-ischemic encephalopathy are presented. The predictors of outcome that can be evaluated in the neonatal period are also reviewed, as this information may assist in the counseling of families. Most trials of hypothermia have been performed in high-resource countries; published studies from the low- and middle-income countries are also reviewed.

Apgar scores at 10 min and outcomes at 6-7 years following hypoxic-ischaemic encephalopathy

AIM

To determine the association between 10 min Apgar scores and 6-7-year outcomes in children with perinatal hypoxic-ischaemic encephalopathy (HIE) enrolled in the National Institute of Child Health and Human Development Neonatal Research Network (NICHD NRN) whole body cooling randomised controlled trial (RCT).

METHODS

Evaluations at 6-7 years included the Wechsler Preschool and Primary Scale of Intelligence III or Wechsler Intelligence Scale for Children IV and Gross Motor Functional Classification Scale. Primary outcome was death/moderate or severe disability. Logistic regression was used to examine the association between 10 min Apgar scores and outcomes after adjusting for birth weight, gestational age, gender, outborn status, hypothermia treatment and centre.

RESULTS

In the study cohort (n=174), 64/85 (75%) of those with 10 min Apgar score of 0-3 had death/disability compared with 40/89 (45%) of those with scores >3. Each point increase in 10 min Apgar scores was associated with a significantly lower adjusted risk of death/disability, death, death/IQ <70, death/cerebral palsy (CP) and disability, IQ<70 and CP among survivors (all p<0.05). Among the 24 children with a 10 min Apgar score of 0, five (20.8%) survived without disability. The risk-adjusted probabilities of death/disability were significantly lower in cooled infants with Apgar scores of 0-3; there was no significant interaction between cooling and Apgar scores (p=0.26).

CONCLUSIONS

Among children with perinatal HIE enrolled in the NICHD cooling RCT, 10 min Apgar scores were significantly associated with school-age outcomes. A fifth of infants with 10 min Apgar score of 0 survived without disability to school age, suggesting the need for caution in limiting resuscitation to a specified duration.

Perinatal asphyxia with hyperoxemia within the first hour of life is associated with moderate to severe hypoxic-ischemic encephalopathy

OBJECTIVE

To determine whether early hyperoxemia in neonates with severe perinatal acidemia is associated with the development of hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We identified 120 infants at ≥ 36 weeks gestational age with perinatal acidosis born at Parkland Hospital who qualified for a screening neurologic exam for cooling therapy. Based on a PaO2 measurement during the first hour of life, the cohort was divided into infants with hyperoxemia (PaO2 >100 mmHg) and those without hyperoxemia (PaO2 ≤ 100 mmHg). The rate of moderate-severe encephalopathy was compared between the groups using χ(2) analysis, as well as multiple logistic regression, taking into account baseline characteristics and confounding variables.

RESULTS

Thirty-six infants (30%) had an initial PaO2 >100 mmHg. Infants with and without hyperoxemia had similar baseline maternal and infant characteristics. Infants with hyperoxemia had a higher incidence of HIE than those without hyperoxemia (58% vs 27%; P = .003). Admission hyperoxemia was associated with a higher risk of HIE (OR, 4; 95% CI, 1.4-10.5; adjusted P = .01). Among the neonates with moderate-severe HIE during the first 6 hours of life, those with hyperoxemia had a higher incidence of abnormal brain magnetic resonance imaging results, consistent with hypoxic ischemic injury, compared with those without hyperoxemia (79% vs 33%; P = .015).

CONCLUSION

In neonates with perinatal acidemia, admission hyperoxemia is associated with a higher incidence of HIE. Among neonates with HIE, admission hyperoxemia is associated with abnormal brain magnetic resonance imaging findings. The judicious use of oxygen during and after resuscitation is warranted.

Addition of SNAP to perinatal risk factors improves the prediction of bronchopulmonary dysplasia or death in critically ill preterm infants

Background

Bronchopulmonary dysplasia (BPD) is the most common serious pulmonary morbidity in premature infants. The score for neonatal acute physiology (SNAP) is a physiologic severity index for neonatal intensive care and correlates well with neonatal mortality and clinical outcomes. The prognostic value of the SNAP score for BPD in preterm infants remains to be clarified. The aim of the study was to determine whether SNAP can predict the development of BPD or death, and to investigate the contribution of SNAP to the predictive accuracy of other potential perinatal risk factors for the adverse outcome in critically ill preterm infants.

Methods

We conducted a study in 160 critically ill preterm infants with less than 33 gestational weeks. The original SNAP score was prospectively calculated based on 28 items collected during the first 24 hours of admission. The potential perinatal risk factors were assessed during the first 72 hours of life. Major outcome measures were BPD and mortality before the time of BPD screening.

Results

Of the 160 infants, 17 died and 41 developed BPD. The SNAP score was significantly associated with BPD or death (odds ratio [OR] =1.28; 95% confidence interval [CI], 1.16-1.41; p <0.001), even after adjustment for gestational age (OR =1.27; 95% CI, 1.13-1.41; p <0.001). High SNAP score was an independent predictor of BPD or death (area under the curve [AUC] =0.78; 95% CI, 0.70-0.85; p <0.001), with additional predictive value when combined with other perinatal risk factors. Multivariate regression analysis resulted in a final model, including SNAP, gestational age, apnea of prematurity, patent ductus arteriosus, and surfactant use as independent risk factors, with a higher predictive accuracy compared with individual components (AUC =0.92; 95% CI, 0.87-0.96; p <0.001).

Conclusions

SNAP is associated with adverse outcome of BPD or death. High SNAP scores are predictive of BPD or death in critically ill preterm infants, and add prognostic value to other perinatal risk factors.

Cooling in the real world: therapeutic hypothermia in hypoxic-ischemic encephalopathy

BACKGROUND AND AIM

The benefits of therapeutic hypothermia have not been assessed from the perspective of the neurology clinic. We aimed to report the impact of the implementation of a local regional therapeutic hypothermia program on the neurodevelopmental outcomes of surviving hypoxic-ischemic encephalopathy (HIE) infants who were followed in the neonatal neurology clinic.

METHODS

Retrospective analysis of term infants referred to the neonatal neurology clinic after having been diagnosed with HIE and meeting eligibility criteria for therapeutic hypothermia between March 1999 and June 2010. Therapeutic hypothermia was implemented in September 2008. Outcome measures were dichotomously defined as: normal or adverse, which included cerebral palsy, global developmental delay, and epilepsy.

RESULTS

Thirty infants were included in the pre-therapeutic hypothermia group. Thirty-one infants received therapeutic hypothermia and 27 were adequately followed and included in the post-therapeutic hypothermia group. The frequency of an adverse outcome was significantly higher in the pre-therapeutic hypothermia infants (19/30 [63%] versus 4/27 [15%]; OR = 0.10; 95% CI, 0.03-0.37; P < 0.001). Neonatal clinical seizures were more frequent in the pre-therapeutic hypothermia group (P = 0.012). There were no differences regarding frequency of fetal distress, rate of caesarean sections, Apgar scores, need of resuscitation, cord/initial blood gases, and degrees of encephalopathy between the two groups.

CONCLUSIONS

The implementation of a regional therapeutic hypothermia program in our institution has vastly reduced the observed neurological morbidity of surviving HIE infants followed in our neonatal neurology clinic. A similar change in outcomes of infants with HIE can be anticipated by other centers and other clinics adopting this therapy.

Early clinical predictors of a severely abnormal amplitude-integrated electroencephalogram at 48 hours in cooled neonates

AIM

There is a need to identify infants with hypoxic ischaemic encephalopathy who have a poor outcome despite therapeutic hypothermia. A severely abnormal amplitude-integrated electroencephalogram at 48 h predicts death or disability. Our aim was to determine whether clinical assessment at age 3-5 h predicts a severely abnormal amplitude-integrated electroencephalogram at 48 h or death in cooled infants.

METHODS

Forty-one cooled infants, ≥36 weeks' gestation, with moderate-to-severe hypoxic ischaemic encephalopathy, were prospectively enrolled. Infants who were moribund, had congenital conditions associated with encephalopathy or had severe cardio-respiratory instability were excluded. The predictive abilities of the Thompson encephalopathy score and individual signs at age 3-5 h were assessed.

RESULTS

All infants with a Thompson score ≥16 at 3-5 h had a severely abnormal amplitude-integrated electroencephalogram at 6 h and an abnormal short-term outcome. At 48 h, 75% had a severely abnormal aEEG or died vs. 18% with a score <16 (p = 0.004). Multivariate analysis did not find a significant independent association with any of the individual signs.

CONCLUSION

The Thompson score could be useful to identify infants who will have a poor outcome despite cooling. A score ≥16 should be validated as a prespecified variable in prospective studies.

Does clinical status 1 week after therapeutic hypothermia predict brain MRI abnormalities?

OBJECTIVE

Hypothermia improves clinical outcomes and brain magnetic resonance imaging (MRI) findings in infants with hypoxic-ischemic encephalopathy. We hypothesized that clinical status following hypothermia predicts brain MRI abnormalities, and helps determine which infants need an early MRI evaluation before discharge. The objective of this study was to determine whether the clinical evaluation 1 week after completion of 72 h of hypothermia treatment predicts the presence of brain MRI abnormalities related to hypoxia-ischemia.

STUDY DESIGN

The medical records of 83 consecutively cooled infants who underwent brain MRI were reviewed. Clinical evaluation by day 10 of life consisted of assessment of oral feeding ability, spontaneous activity, need for mechanical ventilation and a history of clinical seizures. Logistic regression analysis was performed using all four covariates, with an abnormal MRI as the primary outcome. Brain MRI with lesions in both the basal nuclei and the cortex was considered to be severely abnormal.

RESULT

MRI was abnormal in 46 (55%) infants. Univariate analysis identified all of the criteria as being significantly associated with an abnormal MRI. On multivariate analysis, only feeding difficulty (P<0.001, OR 9.5, 95% confidence interval (CI) 3 to 29.8) and a history of clinical seizures (P<0.001, OR 12, 95% CI 3 to 46.5) were significantly associated with an abnormal MRI. The areas under the receiver operating characteristic curve for feeding ability and seizure activity combined (0.86, 95% CI 0.77 to 0.94) indicated good accuracy with respect to the primary outcome. The negative predictive values of feeding difficulty and seizure activity for a severely abnormal MRI were 91% and 96%, respectively.

CONCLUSION

Infants who do not have a history of clinical seizures and who attained full oral feeding by 1 week after hypothermia are unlikely to have an abnormal brain MRI. This simple assessment provides significant prognostic information that can be useful in parental counseling, and may allow selective use of pre-discharge MRI.

Serum biomarkers of MRI brain injury in neonatal hypoxic ischemic encephalopathy treated with whole-body hypothermia: a pilot study

OBJECTIVES

To determine if candidate biomarkers, ubiquitin carboxyl-terminal esterase L1 and glial fibrillary acidic protein, are elevated in neonates with hypoxic ischemic encephalopathy who die or have severe MRI injury compared with surviving infants with minimal or no injury on brain MRI.

DESIGN

Prospective observational study.

SETTING

Level IIIC outborn neonatal ICU in a free-standing children's hospital.

PATIENTS

Term newborns with moderate-to-severe hypoxic ischemic encephalopathy referred for therapeutic hypothermia

INTERVENTIONS

Serum specimens were collected at 0, 12, 24, and 72 hours of cooling. MRI was performed in surviving infants at target 7-10 days of life and was scored by a pediatric neuroradiologist masked to biomarker and clinical data.

MEASUREMENTS AND MAIN RESULTS

Serial biomarker levels were determined in 20 hypoxic ischemic encephalopathy patients. Ubiquitin carboxyl-terminal esterase L1 was higher at initiation and 72 hours of cooling, while glial fibrillary acidic protein was higher at 24 and 72 hours in babies with adverse outcome compared with those with favorable outcome.

CONCLUSIONS

This preliminary data support further studies to evaluate ubiquitin carboxyl-terminal esterase L1 and glial fibrillary acidic protein as immediate biomarkers of cerebral injury severity in newborns with hypoxic ischemic encephalopathy.