title: A matched cohort study of postoperative outcomes in obstructive sleep apnea: could preoperative diagnosis and treatment prevent complications?
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is associated with increased risk of postoperative complications. The authors investigated whether preoperative diagnosis and prescription of continuous positive airway pressure therapy reduces these risks.
  
  
  METHODS
  Matched cohort analysis of polysomnography data and Manitoban health administrative data (1987 to 2008). Postoperative outcomes in adult OSA patients up to 5 yr before (undiagnosed OSA, n = 1,571), and any time after (diagnosed OSA, n = 2,640) polysomnography and prescription of continuous positive airway pressure therapy for a new diagnosis of OSA, were compared with controls at low risk of having sleep apnea (n = 16,277). Controls were matched by exact procedure, indication, and approximate date of surgery. Procedures used to treat sleep apnea were excluded. Follow-up was at least 7 postoperative days. Results were reported as odds ratio (95% CI) for OSA or subgroup versus controls.
  
  
  RESULTS
  In multivariate analyses, the risk of respiratory complications (2.08 [1.35 to 3.19], P < 0.001) was similarly increased for both undiagnosed and diagnosed OSA. The risk of cardiovascular complications, primarily cardiac arrest and shock, was significantly different (P = 0.009) between undiagnosed OSA (2.20 [1.16 to 4.17], P = 0.02) and diagnosed OSA patients (0.75 [0.43 to 1.28], P = 0.29). For both outcomes, OSA severity, type of surgery, age, and other comorbidities were also important risk modifiers.
  
  
  CONCLUSIONS
  Diagnosis of OSA and prescription of continuous positive airway pressure therapy were associated with a reduction in postoperative cardiovascular complications. Despite limitations in the data, these results could be used to justify and inform large efficacy trials of perioperative continuous positive airway pressure therapy in OSA patients.
authors.affiliation: From the Department of Anesthesia (T.C.M.), Manitoba Centre for Health Policy, Department of Community Health Sciences (D.C.), Departments of Community Health Sciences and Pediatrics and Child Health (M.M.), Departments of Medicine and Community Health Sciences (C.R.), and Department of Community Health Sciences (L.L.R.), University of Manitoba, Winnipeg, Manitoba, Canada; and Yale University School of Medicine, Section of Pulmonary, Critical Care and Sleep Medicine, VA Connecticut Healthcare System, West Haven, Connecticut (M.K.).
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Mutter
authors.forename: Dan
authors.initials: D
authors.lastname: Chateau
authors.forename: Michael
authors.initials: M
authors.lastname: Moffatt
authors.forename: Clare
authors.initials: C
authors.lastname: Ramsey
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Roos
authors.forename: Meir
authors.initials: M
authors.lastname: Kryger
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods*; D012042:Registries; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome