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

Neonatal encephalopathy multiorgan scoring systems: systematic review

Introduction

Neonatal encephalopathy (NE) is a condition with multifactorial etiology that causes multiorgan injury to neonates. The severity of multiorgan dysfunction (MOD) in NE varies, with therapeutic hypothermia (TH) as the standard of care. The aim is to identify current approaches used to assess and determine an optimum scoring system for MOD in NE.

Methods

The systematic review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An electronic search was conducted using PubMed, EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, and CINAHL for studies of scoring systems for MOD in NE.

Results

The search yielded 628 articles of which 12 studies were included for data extraction and analysis. Five studies found a positive correlation between the severity of NE and MOD. There was significant heterogeneity across the scoring systems, including the eligibility criteria for participants, the methods assessing specific organ systems, the length of follow-up, and adverse outcomes. The neurological, hepatic, cardiovascular, respiratory, hematological, and renal systems were included in most studies while the gastrointestinal system was only in three studies. The definitions for hepatic, renal, and respiratory systems dysfunction were most consistent while the cardiovascular system varied the most.

Discussion

A NE multiorgan scoring system should ideally include the renal, hepatic, respiratory, neurological, hematological, and cardiovascular systems. Despite the heterogeneity between the studies, these provide potential candidates for the standardization of MOD scoring systems in NE. Validation is needed for the parameters with adequate length of follow-up beyond the neonatal period. Additionally, the evaluation of MOD may be affected by TH considering its multiorgan effects.

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.

Subcortical brain volumes in neonatal hypoxic-ischemic encephalopathy

BACKGROUND

Despite treatment with therapeutic hypothermia, hypoxic-ischemic encephalopathy (HIE) is associated with adverse developmental outcomes, suggesting the involvement of subcortical structures including the thalamus and basal ganglia, which may be vulnerable to perinatal asphyxia, particularly during the acute period. The aims were: (1) to examine subcortical macrostructure in neonates with HIE compared to age- and sex-matched healthy neonates within the first week of life; (2) to determine whether subcortical brain volumes are associated with HIE severity.

METHODS

Neonates (n = 56; HIE: n = 28; Healthy newborns from the Developing Human Connectome Project: n = 28) were scanned with MRI within the first week of life. Subcortical volumes were automatically extracted from T1-weighted images. General linear models assessed between-group differences in subcortical volumes, adjusting for sex, gestational age, postmenstrual age, and total cerebral volumes. Within-group analyses evaluated the association between subcortical volumes and HIE severity.

RESULTS

Neonates with HIE had smaller bilateral thalamic, basal ganglia and right hippocampal and cerebellar volumes compared to controls (all, p < 0.02). Within the HIE group, mild HIE severity was associated with smaller volumes of the left and right basal ganglia (both, p < 0.007) and the left hippocampus and thalamus (both, p < 0.04).

CONCLUSIONS

Findings suggest that, despite advances in neonatal care, HIE is associated with significant alterations in subcortical brain macrostructure.

IMPACT

Compared to their healthy counterparts, infants with HIE demonstrate significant alterations in subcortical brain macrostructure on MRI acquired as early as 4 days after birth. Smaller subcortical volumes impacting sensory and motor regions, including the thalamus, basal ganglia, and cerebellum, were seen in infants with HIE. Mild and moderate HIE were associated with smaller subcortical volumes.

Predictive value of the Thompson score for short-term adverse outcomes in neonatal encephalopathy

BACKGROUND

To explore the predictive value of the Thompson score during the first 4 days of life for estimating short-term adverse outcomes in neonatal encephalopathy.

METHODS

This observational study evaluated infants with neonatal encephalopathy (≥36 weeks of gestation) registered in a multicenter cohort of cooled infants in Japan. The Thompson score was evaluated at 0-24, 24-48, 48-72, and 72-90 h of age. Adverse outcomes included death, survival with respiratory impairment (requiring tracheostomy), or survival with feeding impairment (requiring gavage feeding) at discharge.

RESULTS

Of the 632 infants, 21 (3.3%) died, 59 (9.3%) survived with respiratory impairment, and 113 (17.9%) survived with feeding impairment. The Thompson score throughout the first 4 days accurately predicted death, respiratory impairment, or feeding impairment. The 72-90 h score showed the highest accuracy. A cutoff of ≥15 had a sensitivity of 0.85 and specificity of 0.92 for death or respiratory impairment, while a cutoff of ≥14 had a sensitivity of 0.71 and a specificity of 0.92 for death, respiratory or feeding impairment.

CONCLUSION

A high Thompson score during the first 4 days of life, especially at 72-90 h could thus be useful for estimating the need for prolonged life support.

IMPACT

The Thompson score on days 1-4 of age was useful in predicting death and respiratory or feeding impairments. The 72-90 h Thompson score showed the highest predictive capability. Owing to the rarity of withdrawal of life-sustaining treatment in Japan, 43% of infants with persistent severe encephalopathy with a Thompson score of ≥15 at 72-90 h of age could regain spontaneous breathing, be extubated, and survive without tracheostomy. Meanwhile, approximately 50% of infants who survived without tracheostomy required gavage feeding. Our results could provide useful information for clinical decision making regarding infants with persistent severe encephalopathy.

The influence of late prematurity on the encephalopathy exam of infants with neonatal encephalopathy

BACKGROUND

Late preterm (LPT) infants are increasingly treated for hypoxic-ischemic encephalopathy (HIE). However, neurodevelopmental differences of LPT infants may independently influence the neurologic exam and confound care.

METHODS

Perinatal and outcome characteristics were extracted along with the worst autonomic and state/neuromuscular/reflex Sarnat components in a cross-section of infants with moderate/severe HIE. Infants were classified as late preterm (LPT, 34-36 weeks) or term (>36 weeks).

RESULTS

250 infants were identified, 55 were late preterm. LPT infants had lower mean gestational age and birthweight and greater length of stay (LOS). LPT infants had higher median scores for the Moro and respiratory autonomic components, but no difference in total score.

CONCLUSIONS

LPT infants had increased LOS, worse Moro reflex, and respiratory status, but no clinically or statistically significant differences in total Sarnat scores. Although it is important to note the impact of immaturity on the exam, it is unlikely to independently alter management.

Differences in standardized neonatal encephalopathy exam criteria may impact therapeutic hypothermia eligibility

BACKGROUND

Therapeutic hypothermia (TH) is routinely provided to those with moderate or severe neonatal encephalopathy (NE). Subtle differences exist in the standardized exams used to define NE severity. We aimed to assess if an infant's TH eligibility status differed if they were evaluated using either the NICHD/Neonatal Research Network's (NICHD-NRN) or TOBY/British Association of Perinatal Medicine's (TOBY-BAPM) neurological exam.

METHODS

Encephalopathic infants ≥36 weeks with evidence of perinatal asphyxia and complete documentation of the neurological exam &lt;6 h of age were included. TH eligibility using the NICHD-NRN and TOBY-BAPM criteria was determined based upon the documented exams.

RESULTS

Ninety-one encephalopathic infants were included. Despite good agreement between the two exams (κ = 0.715, p &lt; 0.001), TH eligibility differed between them (p &lt; 0.001). A total of 47 infants were deemed eligible by at least one method-46 using NICHD-NRN and 35 using TOBY-BAPM. Of the 12 infants eligible per NICHD-NRN, but ineligible per TOBY-BAPM, two developed electrographic seizures and seven demonstrated hypoxic-ischemic cerebral injury.

CONCLUSIONS

Both the NICHD-NRN and TOBY-BAPM exams are evidence-based. Despite this, there is a significant difference in the number of infants eligible for TH depending on which exam is used. The NICHD-NRN exam identifies a greater proportion as eligible.

IMPACT

There are subtle differences in the NICHD-NRN and TOBY-BAPM's encephalopathy exams used to determine eligibility for TH. This results in a significant difference in the proportion of infants determined to be eligible for TH depending on which encephalopathy exam is used. The NICHD-NRN encephalopathy exam identifies more infants as being eligible for TH than the TOBY-BAPM encephalopathy exam. This may result in different rates of cooling depending on which evidence-based neurological exam for evaluation of encephalopathy a center uses.

Fetal heart rate patterns in labor and the risk of neonatal encephalopathy: A case control study

OBJECTIVE

To describe the accuracy of intrapartum fetal heart rate abnormalities as defined by National Institute of Health and Care Excellence guidelines to predict moderate-severe neonatal encephalopathy of apparent hypoxic-ischemic etiology.

STUDY DESIGN

A case-control study of HIE risk factors was conducted. Eligible babies were born in a single maternity hospital in Dublin, Ireland between September 2006, and November 2017 at ≥35 + 0 weeks' gestational age. Cases were eligible babies with moderate-severe neonatal encephalopathy of definite or apparent hypoxic-ischemic etiology. Controls were eligible babies born before and after each case with normal Apgar scores. The included subjects who had intrapartum fetal heart rate recordings were identified. Pattern features (baseline rate, variability, accelerations, decelerations [early, late, variable, prolonged], bradycardia, sinusoidal pattern) were manually identified blind to all clinical details by one of the authors. Each 15-minute segment was then algorithmically categorized (uninterpretable, normal, suspicious, pathological).

RESULTS

Of 88 cases and 176 controls, 71 cases (81%) and 146 controls (83%) were admitted to the delivery suite in labor. From that group, intrapartum FHR traces longer than 15 min were available for 52 (73%) cases and 118 (83%) controls. The FHR pattern feature with the largest area under the receiver operating characteristic curve was the maximum number of consecutive segments in which the baseline was >160 bpm (0.71 [95% confidence interval: 0.62-0.80]). The category variable with the highest area under the curve was the number of suspicious segments (0.76 [95% confidence interval: 0.67-0.84]). A tri-variate logistic regression model incorporating the total number of segments, the number of "suspicious" segments classed, and the number of "pathological" segments achieved an area under the curve of 0.78 (95% confidence interval: 0.70-0.86). With 95% specificity, this model correctly identified 17 cases (33%) at a median time before delivery of 2 h and 18 min (interquartile range: 01:19-04:40).

CONCLUSIONS

The power of fetal heart rate analysis to predict neonatal encephalopathy is hampered by poor specificity given the rarity of the outcome. When analyzing a suspicious trace, it is beneficial to consider the overall duration of the suspicious pattern.