Postcardiotomy confusion and sleep loss.

To examine the relationship between sleep loss and confusion after open-heart surgery, 27 consecutive patients were monitored 1 day preoperatively and 5 days postoperatively with the Folstein Mini-Mental State examination, a modified sleep latency test, and a sleep log. Confusion (low Mini-Mental State scores) peaked on postoperative Days 1 and 2 and correlated with insomnia (sleep time) during the following night but not during the preceding night. The results suggest that sleep loss is not the cause but, rather, a consequence of postcardiotomy confusion. Confusion, not insomnia, should be the focus of treatment.