title: Relationship between chronic intermittent hypoxia and intraoperative mean arterial pressure in obstructive sleep apnea patients having laparoscopic bariatric surgery.
abstract: BACKGROUND
  Recurrent nocturnal hypoxemia in obstructive sleep apnea enhances sympathetic function, decreases baroreceptor sensitivity, and weakens peripheral vascular responses to adrenergic signals. The authors hypothesized that the percentage of total sleep time spent at oxyhemoglobin saturation (SaO2) less than 90% and minimum nocturnal SaO2 on preoperative polysomnography are associated with decreased intraoperative mean arterial pressure.
  
  
  METHODS
  The authors examined the records of all patients who had laparoscopic bariatric surgery at Cleveland Clinic between 2005 and 2009 and an available polysomnography study. The authors assessed the relationships between the percentage of total sleep time spent at SaO2 less than 90% and minimum nocturnal SaO2, and the time-weighted average of mean arterial pressure. The authors used multivariable regression models to adjust for prespecified clinical confounders.
  
  
  RESULTS
  Two hundred eighty-one patients were included in the analysis. The average change in the time-weighted average of mean arterial pressure was -0.02 (97.5% CI, -0.08, 0.04) mmHg for each 1% absolute increase in the percentage of sleep time spent at SaO2 less than 90% (P = 0.50). The average change was -0.13 (97.5% CI, -0.27, 0.01) mmHg, for each 1% absolute decrease in the minimum SaO2 (P = 0.04 > significance criterion of 0.025, Bonferroni correction). An unplanned analysis estimated 1% absolute decrease in minimum SaO2 was associated with -0.22 (98.75% CI, -0.39, -0.04) mmHg, change in mean arterial pressure (P = 0.002) in the time period between endotracheal intubation and trocar insertion.
  
  
  CONCLUSIONS
  Recurrent nocturnal hypoxemia in obstructive sleep apnea is not a risk marker for intraoperative hypotension.
authors.affiliation: From the Department of Outcomes Research, Cleveland Clinic, Cleveland, Ohio (A.T., C.E., A.F., I.G., Y.E., R.G., D.I.S.); Departments of Quantitative Health Sciences and Outcomes Research, Cleveland Clinic, Cleveland, Ohio (J.Y.); Anesthesiology Institute, Cleveland Clinic, Cleveland, Ohio (A.K., S.B., S.Q., L.A.); Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, California (A.G.D.); and Outcomes Research Consortium, Cleveland, Ohio (A.G.D.). Current affiliations: Boston University, Boston, Massachusetts (C.E.); Department of Anesthesiology, Oregon Health and Science University, Portland, Oregon (A.F.); Department of Anesthesiology, MetroHealth Medical Center/Case Western Reserve University, Cleveland, Ohio (Y.E.); and Internal Medicine, St. Vincent Charity Medical Center, Cleveland, Ohio (R.G.).
authors.forename: Alparslan
authors.initials: A
authors.lastname: Turan
authors.forename: Jing
authors.initials: J
authors.lastname: You
authors.forename: Cameron
authors.initials: C
authors.lastname: Egan
authors.forename: Alex
authors.initials: A
authors.lastname: Fu
authors.forename: Ignazia
authors.initials: I
authors.lastname: Gazmuri
authors.forename: Ashish
authors.initials: A
authors.lastname: Khanna
authors.forename: Yashar
authors.initials: Y
authors.lastname: Eshraghi
authors.forename: Raktim
authors.initials: R
authors.lastname: Ghosh
authors.forename: Somnath
authors.initials: S
authors.lastname: Bose
authors.forename: Shahbaz
authors.initials: S
authors.lastname: Qavi
authors.forename: Lovkesh
authors.initials: L
authors.lastname: Arora
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Doufas
mesh_terms: D062186:Arterial Pressure / Q000502:physiology*; D050110:Bariatric Surgery / Q000379:methods*; D015984:Causality; D002908:Chronic Disease; D015897:Comorbidity; D005260:Female; D006801:Humans; D007022:Hypotension / Q000175:diagnosis / Q000453:epidemiology; D000860:Hypoxia / Q000175:diagnosis / Q000453:epidemiology; D007432:Intraoperative Period; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D016343:Monitoring, Intraoperative / Q000706:statistics & numerical data*; D009765:Obesity / Q000453:epidemiology / Q000601:surgery*; D009820:Ohio; D017286:Polysomnography / Q000379:methods / Q000706:statistics & numerical data*; D012044:Regression Analysis; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology* / Q000503:physiopathology; D013997:Time Factors