Intensive care unit and hospital mortality in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common disorder affecting between 5% and 24% of men and women. The prevalence of OSA in the intensive care unit (ICU) population is unknown. This study was undertaken to determine the prevalence of OSA in patients admitted to the ICU and to determine if OSA is an independent predictor of mortality.

This is a retrospective study using an Acute Physiology and Chronic Health Evaluation III database cross-referenced to a comprehensive clinical database to identify patients with and without OSA admitted to medical, surgical, and mixed ICUs at a large academic medical center.

Between January 2003 and December 2005, 15077 patients were admitted to the ICUs; and of these, 1183 (7.8%) had a physician-documented diagnosis of OSA. Eight hundred thirty-five (71%) patients had polysomnographic testing at our institution with a documented apnea-hypopnea index more than 5 per hour. Patients with OSA were younger (59.1 ± 14.0 vs 62.3 ± 18.0), male (58.9% vs 53.7%), and had lower Acute Physiology and Chronic Health Evaluation III scores (45.3 ± 24.1 vs 54.9 ± 27.7). Predicted mortality (10.3% ± 16.4% vs 16.3 ± 21.7), median ICU length of stay (1.13 vs 1.50 days), ICU mortality (2.4% vs 6.2%), and hospital mortality (3.9% vs 11.4%) were all reduced in patients with OSA, P values < .001. When adjusted for the severity of illness, OSA was independently associated with decreased hospital mortality, (0.408; 95% confidence interval, 0.298-0.557).

Obstructive sleep apnea is common in patients admitted to the ICU. Obstructive sleep apnea was associated with a reduction in both ICU and hospital mortality.