Abstract 03: Early Post-Cardiac Arrest Blood Pressure Thresholds Associated with Outcomes: A Secondary Analysis of the ICU-Resuscitation Trial

Abstract

Introduction: Though early hypotension after pediatric in-hospital cardiac arrest (IHCA) is associated with inferior outcomes, ideal post-arrest blood pressure (BP) targets have not been established. We aimed to leverage prospectively collected BP data to explore the association of post-arrest BP thresholds with outcomes. We hypothesized that maintaining BPs greater than the newly identified post-arrest systolic and diastolic BP thresholds early after IHCA are associated with higher rates of survival to hospital discharge. Methods: We performed a secondary analysis of prospectively collected BP data from the first six hours following index IHCA events enrolled in the ICU-Resuscitation trial. The lowest documented systolic BP (SBP) and diastolic BP (DBP) 0-6 hours post-arrest were categorized by age-based percentiles. After controlling for illness category and presence of pre-arrest hypotension (systolic or mean arterial blood pressure <5 th percentile-for-age or vasoactive/inotropic requirement), cubic spline analyses were generated exploring the association of lowest post-arrest SBP and DBP with survival to hospital discharge and survival with favorable neurologic outcome (Pediatric Cerebral Performance Category of 1-3 or no change from baseline). Clinical judgement and visual assessment of the spline curves were used to identify BP thresholds. Logistic regression models accounting for illness category and pre-arrest hypotension examined the associations of these thresholds with outcomes. Results: Among 693 index events with 0-6 hour post-arrest BP data, identified thresholds were: SBP >10 th percentile and DBP >50 th percentile for age. Fifty-one percent (n=352) of subjects had lowest SBP above threshold, 50% (n=346) had DBP above threshold. SBP and DBP above thresholds were each associated with survival to hospital discharge (SBP aRR 1.21; 95% CI 1.10, 1.33; DBP aRR 1.23; 1.12, 1.34) and favorable neurologic outcome (SBP aRR 1.22; 1.10, 1.35; DBP aRR 1.27; 1.15, 1.40) (all p<0.001). Conclusions: These data establish that SBP >10 th percentile-for-age and DBP >50 th percentile-for-age during the first 6 hours post-arrest were associated with higher rates of survival to hospital discharge and favorable neurologic outcome.