title: Continuous Positive Airway Pressure Mitigates Opioid-induced Worsening of Sleep-disordered Breathing Early after Bariatric Surgery.
abstract: BACKGROUND
  Bariatric surgery patients are vulnerable to sleep-disordered breathing (SDB) early after recovery from surgery and anesthesia. The authors hypothesized that continuous positive airway pressure (CPAP) improves postoperative oxygenation and SDB and mitigates opioid-induced respiratory depression.
  
  
  METHODS
  In a randomized crossover trial, patients after bariatric surgery received 30% oxygen in the postanesthesia care unit (PACU) under two conditions: atmospheric pressure and CPAP (8 to 10 cm H2O). During 1 h of each treatment, breathing across cortical arousal states was analyzed using polysomnography and spirometry. Arousal state and respiratory events were scored in accordance with American Academy of Sleep Medicine guidelines. Data on opioid boluses in the PACU were collected. The primary and secondary outcomes were the apnea hypopnea index (AHI) and apnea after self-administration of opioids in the PACU. Linear mixed model analysis was used to compare physiologic measures of breathing.
  
  
  RESULTS
  Sixty-four percent of the 33 patients with complete postoperative polysomnography data demonstrated SDB (AHI greater than 5/h) early after recovery from anesthesia. CPAP treatment decreased AHI (8 ± 2/h vs. 25 ± 5/h, P < 0.001), decreased oxygen desaturations (5 ± 10/h vs. 16 ± 20/h, P < 0.001), and increased the mean oxygen saturation by 3% (P = 0.003). CPAP significantly decreased the respiratory-depressant effects observed during wakefulness-sleep transitions without affecting hemodynamics. The interaction effects between CPAP treatment and opioid dose for the dependent variables AHI (P < 0.001), inspiratory flow (P = 0.002), and minute ventilation (P = 0.015) were significant.
  
  
  CONCLUSIONS
  This pharmacophysiologic interaction trial shows that supervised CPAP treatment early after surgery improves SDB and ameliorates the respiratory-depressant effects of opioids without undue hemodynamic effects.
authors.affiliation: From the Department of Anesthesia, Critical Care and Pain Medicine (S.Z., C.H.S., S.A.M., S.D.G., T.M., D.D-.G., M.E.), Department of Surgery (M.M.H.), and Respiratory Care, Department of Anesthesia, Critical Care and Pain Medicine (D.H.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Sleep Medicine, Department of Neurology, Rheinische Friedrich-Wilhelms-University, Bonn, Germany (S.Z.); German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Bonn, Germany (S.Z.); Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, Michigan (S.K.R.); Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California San Diego, La Jolla, California (A.M.); and Department of Anesthesia and Critical Care, University Hospital Essen, Essen, Germany (M.E.).
authors.forename: Sebastian
authors.initials: S
authors.lastname: Zaremba
authors.forename: Christina H
authors.initials: CH
authors.lastname: Shin
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Hutter
authors.forename: Sanjana A
authors.initials: SA
authors.lastname: Malviya
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Grabitz
authors.forename: Teresa
authors.initials: T
authors.lastname: MacDonald
authors.forename: Daniel
authors.initials: D
authors.lastname: Diaz-Gil
authors.forename: Satya Krishna
authors.initials: SK
authors.lastname: Ramachandran
authors.forename: Dean
authors.initials: D
authors.lastname: Hess
authors.forename: Atul
authors.initials: A
authors.lastname: Malhotra
authors.forename: Matthias
authors.initials: M
authors.lastname: Eikermann
mesh_terms: D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects*; D001143:Arousal; D050110:Bariatric Surgery; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D011183:Postoperative Complications / Q000139:chemically induced* / Q000628:therapy*; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000517:prevention & control; D015656:Respiratory Mechanics; D012891:Sleep Apnea Syndromes / Q000139:chemically induced* / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000701:Analgesics, Opioid; D010100:Oxygen