Resident Physician Kaiser Permanente Kaiser Foundation Health Plan Inc San Jose, California, United States
Background: Neonates with mild hypoxic-ischemic encephalopathy (HIE) were thought to have excellent neurodevelopmental outcomes, so were excluded in randomized controlled cooling trials. Recent studies suggest adverse outcomes for mild HIE.
Objective: This study aims to describe the prevalence of mild HIE as well as short and long-term outcomes.
Design/Methods: We performed electronic medical record (EMR) review of infants ≥ 35 weeks gestation born in 15 Kaiser Permanente Hospitals between January 1st, 2014 and December 31st, 2017. Study criteria included pH ≤7.0 or base deficit ≥16 mmol/L in arterial or venous cord blood or any blood specimen in the 1st hour of life. If the pH was 7.01-7.15 or base deficit 10-15.9 mmol/L, or if a blood gas was unavailable, additional criteria included 10-minute Apgar ≤ 5 or ventilation initiated at birth & continued for 10 minutes (Figure 1). Evidence of encephalopathy was assessed by E-score (Figure 2) or EMR review of neurologic exam. Definite or possible mild HIE cases were identified and only definite HIE was used for analysis. Short-term outcomes included laboratory evidence of end-organ injury, NICU admission, tube feeding, respiratory support, persistent neurologic issues at discharge, and neuroimaging abnormalities. Long-term outcomes were assessed at 24-36 months using ICD-10 codes for cerebral palsy, autism spectrum disorder, developmental disorder, motor, speech delay, and seizure disorder. Infants with ≥6 month lapse in Kaiser membership were excluded.
Results: Of 156,501 infants born during the study period, 130 infants or 0.83 per 1000 live births were identified with mild HIE giving a prevalence of 0.08%. Abnormal short-term outcomes: NICU admission (84%), tube feeding (23%), respiratory support (61%), and persistent neurologic issues (8%). MRI, EEG and aEEG were rarely performed. Among infants with laboratory evaluations, ALT was elevated in 55%, AST was elevated in 43%, and creatinine was elevated in 4%. Long-term follow-up was available in 99 (73%), 1% had cerebral palsy, 4% had ASD, 19% had any developmental disorder, 18% had speech delay and 5% had motor delay (Table 2). Conclusion(s): In our large multi-center cohort of newborns with mild HIE, there were significant short and long-term adverse outcomes. Developmental disorders and speech delay were identified and suggested that there may be more adverse long-term neurodevelopmental outcomes than previously described. Large trials are required to see if neuroprotective strategies can reduce the incidence of abnormal neurodevelopmental outcomes.
Flow Diagram for Selection of Infants with mild HIE
Authors/Institutions: Vishnu-Priya Akula, Kaiser Permanente Northern California, Walnut Creek, California, United States; Achyuth Sriram, Kaiser Foundation Health Plan Inc, San Jose, California, United States; Eileen Walsh, Kaiser Permanente Northern California, Oakland, California, United States; Sherian Li, Kaiser Permanente Northern California, Oakland, California, United States; Krisa P. Van Meurs, Stanford University, Palo Alto, California, United States; Matthew W. Cranshaw, Kaiser Foundation Health Plan Inc, San Jose, California, United States; Michael W. Kuzniewicz, Kaiser Permanente Northern California, San Francisco, California, United States
