Early neurologic exam is not reliable for prognostication in post-cardiac arrest patients who undergo therapeutic hypothermia

Abstract Background Recent advances in post-cardiac arrest (CA) care including therapeutic hypothermia (TH) have improved survival and favorable neurologic outcomes for survivors of CA. Survivors often present with deep coma and lack of brainstem reflexes, which is generally associated with adverse outcomes in many disease processes. Little is known regarding the role of initial emergency department (ED) neurological exam testing and its potential for prognostication. Objectives The purpose of this study is to determine if components of a standardized neurologic examination are reliable prognosticators in patients recently resuscitated from CA. We hypothesize that lack of neurologic function does not reliably predict an adverse outcome and, therefore, should not be used to determine eligibility for TH. Methods A standardized neurologic exam was performed in the ED on a prospective, convenience cohort of post-CA patients presenting to a cardiac arrest resuscitation center who would undergo a comprehensive post-arrest care pathway that included TH. Data such as prior sedation or active neuromuscular blockade (NMB) was documented to evaluate for the presence of possible confounders. Exam findings were then compared to hospital survival and neurologic outcome at discharge as defined by the cerebral performance category (CPC) score as documented in the institutional TH registry. Results Forty-nine subjects were enrolled, most of whom presented comatose with a GCS of 3 (n = 41, 83.7%). Nineteen subjects (38.8%) had absence of all exam findings, of which 4/19 (21.1%) survived to hospital discharge. Of those with at least one positive exam finding, 13/30 subjects (43.3%) survived to hospital discharge. Subgroup analysis showed that 9 of the 19 patients with absence of brainstem reflexes did not have evidence of active NMB at the time of the exam; 2/9 (22.1%) survived to hospital discharge. Eight of these subjects in this group had not received any prior sedation; 1/8 (12.5%) survived to hospital discharge. Only 1 of the 17 subjects who survived was discharged with poor neurologic function with a CPC score = 3, while all others who survived had good neurologic function, CPC score = 1. Conclusion In this cohort of patients treated in a comprehensive post-arrest care pathway that included TH, absence of neurologic function on initial ED presentation was not reliable for prognostication. Given these findings, clinicians should refrain from using the initial ED neurolo