title: Postoperative Oxygen Therapy in Patients With OSA: A Randomized Controlled Trial.
abstract: BACKGROUND
  Surgical patients with OSA are at increased risk for perioperative complications. Postoperative supplemental oxygen is commonly used, but it may contribute to respiratory depression in patients with OSA receiving opioids. The objective of the study is to investigate the effect of postoperative supplemental oxygen on arterial oxygen saturation (Sao2), sleep respiratory events, and CO2level in patients with untreated OSA.
  
  
  METHODS
  Consented patients with an apnea hypopnea index (AHI) > 5 events per hour on a preoperative polysomnography were randomized (1:1) to oxygen (O2group) or no oxygen (control group). The O2group received oxygen at 3 L/min via nasal prongs for three postoperative nights. The primary outcomes were polysomnographic parameters measuring Sao2, sleep respiratory events, and Pco2measured by transcutaneous CO2monitor (PtcCO2) on nights 1 through 3. The intention-to-treat and per protocol analysis were completed.
  
  
  RESULTS
  There were 123 patients randomized (O2group: n = 62; control group: n = 61). On night 3, the O2vs control group had a higher average Sao2(95.2% ± 3% vs 91.4% ± 4%, respectively; P < .001) and lower oxygen desaturation index (median, 2.3; 25th-75th percentile, 0.2-13.8 vs median, 18.5; 25th-75th percentile, 8.2-45.9 events per hour, respectively; P < .0001). The O2group had a decreased AHI (median, 8.0; 25th-75th percentile, 2.1-19.9 vs median, 15.6; 25th-75th percentile, 9.5-45.8, respectively; P = .016), hypopnea index (P < .001), and central apnea index (P = .026) and a shortened longest apnea hypopnea duration (P = .002). Although time percentage with PtcCO2≥ 55 mm Hg ≥ 10% on postoperative night 1, 2, or 3 was found in 11.4% patients, there was no difference in PtcCO2between the groups.
  
  
  CONCLUSIONS
  Postoperative supplemental oxygen was found to improve oxygenation and decrease the AHI without increasing the duration of apnea-hypopnea event or PtcCO2level. A small number of patients had significant CO2retention while receiving supplemental oxygen.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT01552304; URL: www.clinicaltrials.gov.
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Pu
authors.initials: P
authors.lastname: Liao
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: Wong
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: David T
authors.initials: DT
authors.lastname: Wong
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Sazzadul
authors.initials: S
authors.lastname: Islam
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Maged
authors.initials: M
authors.lastname: Andrawes
authors.affiliation: Department of Psychiatry, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
authors.forename: Colin M
authors.initials: CM
authors.lastname: Shapiro
authors.affiliation: Department of Sleep Medicine, Brigham and Women's Hospital, Boston, MA; Department of Medicine, Harvard Medical School, Boston, MA.
authors.forename: David P
authors.initials: DP
authors.lastname: White
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada. Electronic address: Frances.chung@uhn.ca.
authors.forename: Frances
authors.initials: F
authors.lastname: Chung
mesh_terms: D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects; D001049:Apnea / Q000453:epidemiology*; D001785:Blood Gas Monitoring, Transcutaneous; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy; D017286:Polysomnography; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology*; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000453:epidemiology*; D012890:Sleep; D020181:Sleep Apnea, Obstructive
chemical_list: D000701:Analgesics, Opioid
keywords: hypoventilation; oxygen; sleep apnea; surgery