Objective: Sleep-related breathing disorder (SRBD) is more prevalent in stroke patients than in age- and sex-matched controls, but the relationship between SRBD, functional levels at admission, and subsequent recovery is unclear. We evaluated patients after a first stroke to determine the prevalence of SRBD and the influence of SRBD on the recovery of discharge functional status after a rehabilitation program.
Design: In a prospective study, 30 stroke patients were studied by continuous overnight pulse oximetry during sleep for the presence of desaturation events (fall of arterial saturation of > 4% from the baseline). The Respiratory Disturbance Index was defined as number of desaturations per hour of sleep. Functional assessment was done at admission using the FIM instrument. The patients were asked about total hours of sleep and the presence or absence of habitual snoring before and after the stroke. The outcome measure at discharge was the FIM score.
Results: On linear regression, after including the FIM score at admission, in the model, the Respiratory Disturbance Index score was negatively correlated with the FIM gain (coefficient, -0.635 +/- 0.27; P = 0.025), and together, the variables explained 20.9% of the total variance (adjusted r2). All patients with an admission FIM score of > or = 70 (only mild functional impairment) had a good outcome (FIM score of > 100 at discharge). However, only two of six of those with FIM scores of < 70 with SRBD (defined as a Respiratory Disturbance Index score of > 10) had significant improvement (> or = 30 points), whereas this occurred in seven of nine of those without SRBD (prevalence ratio, 0.43; 95% confidence interval, 0.13-1.40; P = 0.085)
Conclusions: Even after adjusting for the admission functional status, the presence of hypoxic events during sleep predicts a poorer recovery, especially in stroke patients with poor function at admission.