Immediate prediction of recovery of consciousness after cardiac arrest

Abstract

Objective: Short-latency somatosensory evoked potential (SSEP) monitoring has been reported to be useful in predicting neurological outcome in patients with cardiac arrest and hypoxic-ischemic encephalopathy. To obtain the immediate data of SSEP and evaluate the relationship between the presence of cortical activity and the recovery of consciousness, SSEP was recorded immediately after return of spontaneous circulation.

Design and setting: Prospective observational study in an intensive care unit of a university general hospital.

Patients: The study included 30 patients resuscitated from out-of-hospital cardiac arrest.

Interventions: Basic and advanced cardiac life support, and intensive care.

Measurements and results: SSEP were recorded between 40 and 170 min (median 65) after spontaneous circulation returned. In the initial study all 30 patients showed the Erb's point potential and the N11-13 component, while only 12 (40%) showed cortical activity. Patients were assessed neurologically for recovery of consciousness until 1 month after cardiac arrest. Of 12 these patients 8 recovered consciousness within 10 days, while all patients without cortical activity died without opening their eyes.

Conclusion: Even immediately following resuscitation, absence of cortical activity in SSEP indicates unlikelihood of recovering consciousness, while the preservation of such activity suggests that consciousness is improved. The result promises further accumulation of patients to validate the predictive ability of SSEP in managing postresuscitated patients.