Association of EEG Response to Hypertonic Saline and Neurologic Outcomes in Pediatric Acute Brain Injury

BACKGROUND: Electroencephalography (EEG) is a critical tool for neuromonitoring and neuroprognostication in children with acute brain injury. Quantitative EEG (qEEG), particularly the alpha-delta ratio (ADR), can detect worsening cerebral ischemia in adults, but it is unknown whether it can identify more subtle and transient changes in cerebral blood flow, such as those induced by hypertonic saline (HTS), in children with acute brain injury. We aimed to determine whether we could identify a cohort of patients with an ADR response to HTS and to evaluate the association between an ADR response and neurologic outcomes in critically ill children with acute brain injury. METHODS: We conducted a retrospective cohort study of patients admitted to a pediatric intensive care unit with acute brain injury who received HTS during EEG monitoring from 2018 to 2023. The ADR was calculated before and after HTS administration. An ADR response was defined as a > 20% increase from baseline to within 30 min of receiving HTS in either hemisphere. The primary outcome was survival with favorable neurologic outcome, defined as a Functional Status Scale score change < 3 from prehospital baseline to discharge. Secondary outcome was survival to hospital discharge. RESULTS: Among 87 patients (median age 10 years [interquartile range 3.6-14.5], 46% female), 28% (24 of 87) had an ADR response to HTS. ADR responders were older (12.9 vs. 8.0 years; p = 0.004) and more likely to have continuous, normal-voltage EEG backgrounds (67% vs. 40%; p = 0.006). Patients with an ADR response had four times increased odds of favorable outcome and survival (odds ratio [OR] 4.0 [95% confidence interval (CI) 1.3-12.7] and OR 3.9 [95% CI 1.0-10.7], respectively). CONCLUSIONS: An ADR increase > 20% following HTS was associated with increased odds of survival with favorable neurologic outcome and survival to hospital discharge in critically ill pediatric patients with acute brain injury. qEEG response to HTS may serve as a real-time, noninvasive biomarker of cerebral perfusion responsiveness.