Abstract 66: Association of Initial Neurological Examination with Survival Following Out-of-Hospital Cardiac Arrest

Abstract

Introduction: Following resuscitation from out-of-hospital cardiac arrest (OHCA), failure to awaken from coma remains a common cause for withdrawal of care. Prior investigations have demonstrated initial organ system dysfunction is associated with survival and neurologic outcome. Hypothesis: We hypothesized that initial neurologic examination would be associated with survival following resuscitation from cardiac arrest. Methods: We conducted a retrospective study of 111 comatose OCHA subjects treated with dedicated post-arrest protocols, including therapeutic hypothermia and hemodynamic optimization. These subjects were prospectively enrolled in a multicenter clinical study examining mitochondrial dysfunction from ischemia-reperfusion injury (COMICA Study Group). Subjects not receiving sedation during the initial examination were eligible for analysis. Neurologic examination was classified using the motor and brainstem subscores of the Full Outline of UnResponsiveness (FOUR). For analysis, subjects were dichotomized as deep coma (FOUR Motor+ Brainstem<4) or not. Survival and good neurologic outcome, defined as a Cerebral Performance Category (CPC) of 1-2 and Modified Rankin Scale (mRS) of 0-3 were compared using chi-squared tests. Results: Mean age was 61 (SD 17) years, 66 (59%) male, witnessed in 91 (82%), and received bystander CPR in 49 (44%) of cases. The predominant rhythm was VF/VT in 56 (50%) and low flow time was 19 (IQR 9, 28) minutes. The initial neurologic examination was obtained without sedation in 54 (49%) of subjects. Subjects with deep coma on initial examination were less likely to survive (18% vs. 65%; p<0.001), or have a good outcome using CPC (15% vs. 45%; p=0.01) or mRS (15% vs. 45%; p=0.01). Conclusions: Deep coma on initial neurologic examination is associated with death prior to discharge and poor neurologic outcome. However, depth of coma alone is insufficient to rule out good outcome.