Sleep organization pattern as a prognostic marker at the subacute stage of post-traumatic coma

Objectives: The aim of this study is to identify the predictive indexes for post-traumatic coma prognosis, which is important to better direct acute and subacute treatments and rehabilitation efforts. The pattern of sleep organization is a potential prognostic marker, but its role has not been established yet in the context of modern critical care. In the present study, we used a new protocol to evaluate the prognostic value of the different levels of sleep-wake organization recorded at the subacute stage of post-traumatic coma. Methods: Twenty-four head-injured comatose patients were monitored with 24h polysomnographic recordings. The predictivity of the different levels of sleep-wake organization on polysomnography was compared with other possible prognostic indexes (i.e. neuroradiological findings, age and Glasgow Coma Scores (GCS)). Main outcome measures were survival and the degree of disability after recovery from coma. Results: The presence of organized sleep patterns, but not GCS, was highly predictive of better outcome (odds ratio=10.78, P=0.01), even after correction for potentially confounding variables with multivariate analysis. Conclusions: Our study demonstrates that the sleep-wake organization pattern based on 24h polysomnographic recordings at the subacute stages of post-traumatic coma is a reliable prognostic marker, both for survival and for functional recovery.