title: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Respiratory Medicine, The Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Leeds, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Turkington
authors.forename: V
authors.initials: V
authors.lastname: Allgar
authors.forename: J
authors.initials: J
authors.lastname: Bamford
authors.forename: P
authors.initials: P
authors.lastname: Wanklyn
authors.forename: M W
authors.initials: MW
authors.lastname: Elliott
mesh_terms: D000368:Aged; D000402:Airway Obstruction / Q000150:complications* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012044:Regression Analysis; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000401:mortality; D020521:Stroke / Q000150:complications* / Q000401:mortality; D016019:Survival Analysis