Sleep in Mechanically Ventilated Patients in the Intensive Care Unit

Objective: Sleep abnormalities are common in critically ill patients. Polysomnography (PSG) is the gold standard in assessing sleep quality. The aim of this prospective study was to monitor the sleep pattern in mechanically ventilated patients with PSG who were admitted to our medical intensive care unit. Materials and Methods: This study was conducted in the Medical Intensive Care Unit of an University Hospital. Patients with endotracheal intubation and mechanical ventilation for at least 24 hours were included in the study. They were monitored for 18 hours per day by continuous PSG. Sleep parameters were recorded; [total sleep time (TST), sleep efficiency (SE) and sleep stages]. Results: Records of 12 patients were evaluated. There were nine males and three females. Median age of patients were 72.5 years (minmax=31-92). Median APACHE II was 19 (min-max=10-27). Median sleep time was 489.5 minutes (180-1105), median SE was 77.1% (24.9-96.5) and median arousal number was 147.5/TST (14-450). While REM sleep and non REM stage 3 sleep time and proportion were found to be decreased, non REM stage 2 sleep time and proportion were increased. Conclusion: We have shown that mechanically ventilated patients have changes in sleep architecture and that they have severe sleep fragmentation. Future research should address the cause of these problems by using methodology for comprehensive assessment of sleep-disrupting factors and by examining the dynamic effects of changes in illness severity on sleep quality.