Prediction of Poor Outcome in Comatose Survivors after Cardiopulmonary Resuscitation with Somatosensory Evoked Potentials and Proton Magnetic Resonance Spectroscopy

ABSTRACT

PURPOSE: The study was conducted to examine the usefulness of somatosensory evoked potentials (SEP) and proton magnetic resonance spectroscopy (1H-MRS) in predicting poor outcomes for comatose survivors after cardiopulmonary resuscitation. METHODS: We investigated 36 patients who were comatose after cardiac arrest. Among them, 35 had short latency SEP, and 27 had 1H-MRS. Both tests were performed in 26 patients. To estimate the cerebral outcome, we used the cerebral performance category (CPC) to classify the outcomes for our patients as good (CPC 1-2) or poor (CPC 3-5). RESULTS: Of the 36 patients, 11(31%) presented with good outcomes (CPC 1-2). A bilaterally absent N20 peak (n=35) predicted poor outcomes with a sensitivity of 54.2% and a specificity of 100%. A lactate-positive resonance (n=27) predicted poor outcomes with a sensitivity of 78.9% and a specificity of 100%. Using a combination of a bilaterally absent N20 peak and a lactate-positive resonance (n=26) predicted poor outcomes with a sensitivity of 94.4% and a specificity of 100%. CONCLUSION: The combination of a bilaterally absent N20 peak and a lactate-positive resonance is better than either alone in predicting poor outcomes in patients who are comatose after cardiac arrest.