Abstract
Objective This study aimed to evaluate the role of an objective physiologic biomarker, arterial
blood pressure variability, for the early identification of adverse short-term electroencephalogram
(EEG) outcomes in infants with hypoxic-ischemic encephalopathy (HIE).
Study Design In this multicenter observational study, we analyzed blood pressure of infants meeting
these criteria: (1) neonatal encephalopathy determined by modified Sarnat exam, (2)
continuous mean arterial blood pressure (MABP) data between 18 and 27 hours after
birth, and (3) continuous EEG performed for at least 48 hours. Adverse outcome was
defined as moderate–severe grade EEG at 48 hours. Standardized signal preprocessing
was used; the power spectral density was computed without interpolation. Multivariate
binary logistic regression was used to identify which MABP time and frequency domain
metrics provided improved predictive power for adverse outcomes compared with standard
clinical predictors (5-minute Apgar score and cord pH) using receiver operator characteristic
analysis.
Results Ninety-one infants met inclusion criteria. The mean gestational age was 38.4 ± 1.8
weeks, the mean birth weight was 3,260 ± 591 g, 52/91 (57%) of infants were males,
the mean cord pH was 6.95 ± 0.21, and 10/91 (11%) of infants died. At 48 hours, 58%
of infants had normal or mildly abnormal EEG background and 42% had moderate or severe
EEG backgrounds. Clinical predictor variables (10-minute Apgar score, Sarnat stage,
and cord pH) were modestly predictive of 48 hours EEG outcome with area under curve
(AUC) of 0.66 to 0.68. A composite model of clinical and optimal time- and frequency-domain
blood pressure variability had a substantially improved AUC of 0.86.
Conclusion Time- and frequency-domain blood pressure variability biomarkers offer a substantial
improvement in prediction of later adverse EEG outcomes over perinatal clinical variables
in a two-center cohort of infants with HIE.
Key Points
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Early outcome prediction in HIE is suboptimal.
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Patterns in blood pressure physiology may be predictive of short-term outcomes.
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Early time- and frequency-domain measures of blood pressure variability predict short-term
EEG outcomes in HIE infants better than perinatal factors alone.
Keywords
neonates - neurology - EEG - blood pressure - hypoxic ischemic encephalopathy
