We speculated that initial middle latency auditory evoked potentials index (MLAEPi) can indicate cerebral function and predict the restoration of spontaneous circulation (ROSC), postresuscitation survival or of neurologic outcomes among patients with cardiac arrest.

This prospective study included 61 patients with cardiac arrest who received basic life support and did not achieve ROSC until arrival at the emergency center between September 2010 and September 2011. All patients were then administered advanced cardiac life support at the emergency department. Initial MLAEPi was immediately measured using an MLAEP monitor (aepEX plus; Audiomex, Glasgow, Scotland, UK) during the first cycle of advanced cardiac life support. Prediction of the ROSC, survival, and good outcome were investigated.

Sixteen patients achieved ROSC (ROSC group), and 45 did not achieve ROSC at the scene (non-ROSC group). The initial MLAEPi was significantly higher in the ROSC than in the non-ROSC group (33 vs 28, P < .01). Four survivors in the ROSC group were classified as good outcomes (Cerebral Performance Category 1 and 2). Initial MLAEPi in survivors were significantly higher than that in nonsurvivors (43 vs 29, P < .01). The receiver operating characteristic curves for the initial MLAEPi with area under the curves was 0.75 (95% confidence interval [CI], 0.62-0.88; P < .01) for ROSC, 0.94 (95% CI, 0.88-1.00; P < 0.01) for survival, and 0.96 (95% CI, 0.89-1.03; P < .01) for a good outcome, respectively.

Initial MLAEPi represented by simple numerical values upon presentation at emergency facilities could predict ROSC, survival, and neurologic outcomes among patients with cardiac arrest.