Prediction of poor outcome within the first 3 days of postanoxic coma

Objective: To determine the optimal timing of somatosensory evoked potential (SSEP) recordings and the additional value of clinical and biochemical variables for the prediction of poor outcome in patients who remain comatose after cardiopulmonary resuscitation (CPR). Methods: A prospective cohort study was conducted in 32 intensive care units including adult patients still unconscious 24 hours after CPR. Clinical, neurophysiologic, and biochemical variables were recorded 24, 48, and 72 hours after CPR and related to death or persisting unconsciousness after 1 month. Results: Of 407 included patients, 356 (87%) had a poor outcome. In 301 of 305 patients unconscious at 72 hours, at least one SSEP was recorded, and in 136 (45%), at least one recording showed bilateral absence of N20. All these patients had a poor outcome (95% CI of false positive rate 0 to 3%), irrespective of the timing of SSEP. In the same 305 patients, neuron-specific enolase (NSE) was determined at least once in 231, and all 138 (60%) with a value > 33 mu g/L at any time had a poor outcome (95% CI of false positive rate 0 to 3%). The test results of SSEP and NSE overlapped only partially. The performance of all clinical tests was inferior to SSEP and NSE testing, with lower prevalences of abnormal test results and wider 95% CI of false positive rates. Conclusion: Poor outcome in postanoxic coma can be reliably predicted with somatosensory evoked potentials and neuron-specific enolase as early as 24 hours after cardiopulmonary resuscitation in a substantial number of patients.