Effect of upper airway obstruction in acute stroke on functional outcome at 6 months

Abstract

Background: The aim of this study was to determine whether upper airway obstruction occurring within the first 24 hours of stroke onset has an effect on outcome following stroke at 6 months. Traditional definitions used for obstructive sleep apnoea (OSA) are arbitrary and may not apply in the acute stroke setting, so a further aim of the study was to redefine respiratory events and to assess their impact on outcome. Methods: 120 patients with acute stroke underwent a sleep study within 24 hours of onset to determine the severity of upper airway obstruction (respiratory disturbance index, RDI-total study). Stroke severity (Scandinavian Stroke Scale, SSS) and disability (Barthel score) were also recorded. Each patient was subsequently followed up at 6 months to determine morbidity and mortality. Results: Death was independently associated with SSS (OR (95% CI) 0.92 (0.88 to 0.95), p,0.00001) and RDI-total study (OR (95% CI) 1.07 (1.03 to 1.12), p,0.01). The Barthel index was independently predicted by SSS (p = 0.0001; r = 0.259; 95% CI 0.191 to 0.327) and minimum oxygen saturation during the night (p = 0.037; r = 0.16; 95% CI 0.006 to 0.184). The mean length of the respiratory event most significantly associated with death at 6 months was 15 seconds (sensitivity 0.625, specificity 0.525) using ROC curve analysis. Conclusion: The severity of upper airway obstruction appears to be associated with a worse functional outcome following stroke, increasing the likelihood of death and dependency. Longer respiratory events appear to have a greater effect. These data suggest that long term outcome might be improved by reducing upper airway obstruction in acute stroke.

The Effect of Sleep Disordered Breathing on the Outcome of Stroke and Transient Ischemic Attack: A Systematic Review

“…Study characteristics and main results for these are presented in Table 1. Six studies were European [22][23][24][25][26][27] and two were North American. 19,20 The sample sizes were small, ranging from 47 to 174 stroke or TIA patients.…”

“…20,25 The definition of SDB varied from AHI of 5 events/hour to 20 events/hour. An apnea episode was defined as 10 seconds of cessation of airflow, 22,23,26,27 > 75% decrease, 24 or > 50% decrease in airflow. 25 A hypopnea was defined as a 25% to 50%, 24 ≥ 50%, 22,26,27 or a discernible 23 or clear 25 reduction in airflow or thoraco-abdominal amplitude for ≥ 10 seconds.…”

“…19,20 The sample sizes were small, ranging from 47 to 174 stroke or TIA patients. The study designs included seven prospective cohort studies 19,20,[23][24][25][26][27] and one cross-sectional study. 22 Two studies presented stroke recurrence as a primary outcome, 22,25 five studies addressed all-cause mortality as primary outcome, 19,20,23,26,27 and one study evaluated both fatal and nonfatal cardiovascular events.…”

Rehabilitation of Cardiovascular Disorders and Sleep Apnea

“…Soon after admission to the stroke rehabilitation unit, these patients are more dependent in their ADLs and have longer latency in reaction and in response to verbal stimuli, impairing their ability to acquire new skills. 14 In addition, the presence of SDB was associated with a worse Barthel index at 6 months after stroke 91 and predicted a higher mortality during the following 10 years. 9,53,91 Note that high mortality was found only in patients with OSA but not CSA.…”

“…14 In addition, the presence of SDB was associated with a worse Barthel index at 6 months after stroke 91 and predicted a higher mortality during the following 10 years. 9,53,91 Note that high mortality was found only in patients with OSA but not CSA. 9 Other symptoms in patients with stroke and cardiac disorders are impaired memory, lack of ability to concentrate, and tiredness, which are common in patients with OSA.…”