Hemodynamic, Biochemical, and Ventilatory Parameters are Independently Associated with Outcome after Cardiac Arrest

Hypotension, hyperglycemia, dysoxia, and dyscarbia may contribute to reperfusion injury, and each is independently associated with poor outcome (PO) after cardiac arrest. We investigated whether the combined effects of these physiological derangements are associated with cardiac arrest outcomes.

This institutional review board-approved retrospective cohort study included consecutive resuscitated cardiac arrest patients that received targeted temperature management at Maine Medical Center from 2013 to 2015. We abstracted demographics, intra-arrest factors, and physiological parameters. The primary outcome was dichotomized cerebral performance category (CPC 1-2 vs 3-5) at hospital discharge. After comparing demographics, clinical factors, and persistent post-arrest physiological derangements in patients with good and PO, we constructed a logistic regression model comprised of clinical and demographic factors separately associated with severity, and physiology variables, attempting to evaluate the independent effects of persistent physiological derangements on outcome.

Sixty-eight of 222 (31%) patients had CPC 1-2 (good outcome [GO]) at discharge. In bivariate analysis, factors associated with PO included increased time from collapse to resuscitation, non-shockable rhythm, and age-combined Charlson comorbidity index. In multivariate analysis, each persistent physiological derangement incrementally decreased the likelihood of GO [OR GO per derangement 0.71 (interquartile range [IQR] 0.51-0.99), p = 0.042, area under the curve (AUC) for final model 0.769].

Uncorrected physiological derangements in the first 24 h after cardiac arrest are independently associated with PO. Although causality cannot be established, these findings support preclinical models suggesting that aggressive normalization of physiology after resuscitation may be a reasonable strategy to decrease reperfusion injury.