Prediction of poor outcome in comatose survivors after cardiopulmonary resuscitation with somatosensory evoked potentials and proton magnetic resonance spectroscopy

Abstract

Study objectives: We examine the usefulness of somatosensory evoked potential (SEP) and proton magnetic resonance spectroscopy (MRS) in prediction of poor outcome in comatose survivors after cardiopulmonary resuscitation. Methods: We investigated 36 comatose patients after cardiac arrest. Among them, 35 had short-latency SEP, and 27 had proton MRS. Both tests were performed in 27 patients. For estimation of cerebral outcome, we used the cerebral performance category (CPC) and classified the outcome of our patients as good (CPC 1 to 2) or poor (CPC 3 to 5). Results: Of the 36 patients, 11 (31%) presented with good outcome (CPC 1 to 2). Bilateral absent N 2 O (n=35) predicted poor outcome, with a sensitivity of 54.2% and a specificity of 100%. Lactate-positive resonance (n=27) predicted poor outcome, with a sensitivity of 78.9% and a specificity of 100%. Using bilateral absent N 2 O, lactate-positive resonance or combination (n=26) predicted poor outcome, with a sensitivity of 94.4% and a specificity of 100%. Conclusion: The combination of a bilateral absent N 2 O peak and lactate-positive resonance performs better than either alone in prediction of poor outcome in comatose patients after cardiac arrest.