Survival and recovery of consciousness in anoxic-ischemic coma after cardiopulmonary resuscitation

Objective. In patients who remain unconscious after cardiopulmonary resuscitation (CPR) poor outcome may be predicted with several tests. To use these tests, knowledge of a priori chances of poor outcome after varying periods of unconsciousness is needed. This study is aimed at providing such data. Design and patients. Data regarding survival and recovery of consciousness were extracted from registry-based and prospective cohort studies of patients with anoxic-ischemic coma. A survival analysis was done using Kaplan-Meier estimates and 28-day outcomes were calculated for all patients unconscious after 24 h and 72 h, and 5 days, 7 days and 14 days after CPR. Patient characteristics and outcomes in our cohort were compared with those of published patient series. Results. After 28 days, 27% of 172 patients from the two cohort studies were alive and conscious, 9% were still unconscious, and 64% had died. The proportion of patients who regained consciousness decreased from 34% of those unconscious within the first 6 h post-CPR to 13% of those still unconscious after 2 weeks. The proportion surviving in an unconscious state increased from 6% of patients who were unconscious initially to 33% of those still unconscious after 2 weeks. The chance of survival remained unchanged up to 7 days after CPR, irrespective of the duration of unconsciousness. Patient characteristics and outcomes in our cohort were comparable to data available from the literature. Conclusions. The a priori chances of (poor) outcome vary with the duration of unconsciousness after CPR. This study provides data for different time-intervals after CPR.