Outcome prediction after cardiac arrest

Evaluating prognosis after cardiopulmonary resuscitation (CPR) for cardiac arrest is a “bread and butter” activity for neurologists. It used to be simple. Fewer than 2% of patients hospitalized for out-of-hospital cardiac arrest even survived to discharge, to say nothing about the quality of their neurologic recovery.¹ Hypoxic-ischemic injury was viewed as the most devastating and least treatable cause of coma; for the vast majority of severely injured patients, good recovery was extremely unlikely. This mindset was codified by the seminal 1981 Levy criteria, which heavily influenced a generation of neurologists.² The result of this prediction algorithm was that absent pupillary or corneal reflexes at any time point or absent or extensor motor response at 72 hours virtually assured no chance of good recovery. Neurologists were called into the cardiac care unit to talk to families, confirm the hopelessness of the situation, and “hang the crepe.”

The landscape changed with the publication of the evidence-based 2006 American Academy of Neurology (AAN) Guidelines on Predicting Outcome in Comatose Survivors after Cardiopulmonary Resuscitation.³ This became the new standard instrument for guiding outcome prediction. A large body of research over the intervening 25 years reflected a trend to rely not only on the clinical examination but …