Prognostic value of electrographic postanoxic status epilepticus in comatose cardiac-arrest survivors in the therapeutic hypothermia era

Abstract

Background: The independent prognostic significance of postanoxic status epilepticus (PSE) has not been evaluated prospectively since the introduction of therapeutic hypothermia. We studied 1-year functional outcomes and their determinants in comatose survivors of cardiac arrest (CA), with special attention to PSE.

Methods: 106 comatose CA survivors admitted to the intensive care unit in 2005-2010 were included in a prospective observational study. The main outcome measure was a Cerebral Performance Category scale (CPC) of 1 or 2 (favorable outcome) 1 year after CA.

Results: CA occurred out-of-hospital in 89 (84%) patients and was witnessed from onset in 94 (89%). Median times were 6 min (IQR, 0-11) from CA to first-responder arrival and 23 min (14-40) from collapse to return of spontaneous circulation. PSE was diagnosed in 33 (31%) patients at a median of 39 h (4-49) after CA. PSE was refractory in 24 (22%) cases and malignant in 19 (20%). After 1 year, 31 (29.3%) patients had favorable outcomes including 2 (6.44%) with PSE. Factors independently associated with poor outcome (CPC ≥ 3) were PSE (odds ratio [OR], 14.28; 95% confidence interval [95% CI], 2.77-50.0; P=0.001), time to restoration of spontaneous circulation (OR, 1.04/min; 95% CI, 1-1.07; P=0.035), and LOD score on day 1 (OR, 1.28/point; 95% CI, 1.08-1.54; P=0.003).

Conclusion: PSE strongly and independently predicts a poor outcome in comatose CA survivors receiving therapeutic hypothermia, but some patients with PSE survive with good functional outcomes. PSE alone is not sufficient to predict failure to awaken after CA in the era of therapeutic hypothermia.