Relationship of sleep apnea to functional capacity and length of hospitalization following stroke.

STUDY

OBJECTIVES

Recent evidence indicates that sleep apnea is common in patients with stroke. We hypothesized that the presence of sleep apnea among stroke patients would be associated with a greater degree of functional disability and longer hospitalization following stroke.

DESIGN

Prospective study.

SETTING AND PATIENTS: Sixty-one stroke patients admitted to a stroke rehabilitation unit.

INTERVENTIONS: N/A.

MEASUREMENTS AND

RESULTS

Sleep studies were performed on all patients, and sleep apnea was defined as an apnea-hypopnea index of 10 or more per hour of sleep. Patients underwent functional assessments, including the Functional Independence Measure. Sleep apnea was found in 72% of patients; 60% had predominantly obstructive sleep apnea, while 12% had predominantly central sleep apnea. Although the severity of stroke was similar in the 2 groups, compared to patients without sleep apnea, those with sleep apnea had lower functional capacity [Functional Independence Measure score (mean +/- SEM) 80.2 +/- 3.6 versus 94.7 +/- 4.3, p < 0.05 at admission, and 101.5 +/- 2.8 versus 112.9 +/- 2.7, p < 0.05 at discharge] and spent significantly more days in rehabilitation (45.5 +/- 2.3 versus 32.1 +/- 2.7 days, p < 0.005). In addition, multiple regression analysis showed that obstructive sleep apnea was significantly and independently related to functional impairment and length of hospitalization.

CONCLUSIONS

Sleep apnea is very common among stroke patients undergoing rehabilitation, and its presence is associated with worse functional impairment and a longer period of hospitalization and rehabilitation. These data suggest that sleep apnea may be contributing to functional impairment and prolonged hospitalization following stroke.