title: Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome.
abstract: BACKGROUND
  Obstructive sleep apnoea (OSA) is often undiagnosed before elective surgery and may predispose patients to perioperative complications.
  
  
  METHODS
  A literature search of PubMed-Medline, Web of Science, Scopus, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials up to November 2010 was conducted. Our search was restricted to cohort or case-control studies in adults diagnosed with OSA by screening questionnaire, oximetry, or polysomnography. Studies without controls, involving upper airway surgery, and with OSA diagnosed by ICD-9 codes alone were excluded. The primary postoperative outcomes were desaturation, acute respiratory failure (ARF), reintubation, myocardial infarction/ischaemia, arrhythmias, cardiac arrest, intensive care unit (ICU) transfer, and length of stay.
  
  
  RESULTS
  Thirteen studies were included in the final analysis (n=3942). OSA was associated with significantly higher odds of any postoperative cardiac events [45/1195 (3.76%) vs 24/1420 (1.69%); odds ratio (OR) 2.07; 95% confidence interval (CI) 1.23-3.50, P=0.007] and ARF [33/1680 (1.96%) vs 24/3421 (0.70%); OR 2.43, 95% CI 1.34-4.39, P=0.003]. Effects were not heterogeneous for these outcomes (I(2)=0-15%, P>0.3). OSA was also significantly associated with higher odds of desaturation [189/1764 (10.71%) vs 105/1881 (5.58%); OR 2.27, 95% CI 1.20-4.26, P=0.01] and ICU transfer [105/2062 (5.09%) vs 58/3681 (1.57%), respectively; OR 2.81, 95% CI 1.46-5.43, P=0.002]. Both outcomes showed a significant degree of heterogeneity of the effect among studies (I(2)=57-68%, P<0.02). Subgroup analyses had similar conclusions as main analyses.
  
  
  CONCLUSIONS
  The incidence of postoperative desaturation, respiratory failure, postoperative cardiac events, and ICU transfers was higher in patients with OSA.
authors.affiliation: Department of Hospital Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA. kawr@ccf.org
authors.forename: R
authors.initials: R
authors.lastname: Kaw
authors.forename: F
authors.initials: F
authors.lastname: Chung
authors.forename: V
authors.initials: V
authors.lastname: Pasupuleti
authors.forename: J
authors.initials: J
authors.lastname: Mehta
authors.forename: P C
authors.initials: PC
authors.lastname: Gay
authors.forename: A V
authors.initials: AV
authors.lastname: Hernandez
mesh_terms: D000328:Adult; D015897:Comorbidity; D017558:Elective Surgical Procedures; D006801:Humans; D015994:Incidence; D007442:Intubation, Intratracheal; D009203:Myocardial Infarction / Q000453:epidemiology; D016017:Odds Ratio; D010092:Oximetry; D011183:Postoperative Complications / Q000453:epidemiology*; D012120:Respiration Disorders / Q000453:epidemiology; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*