title: Children with severe OSAS who have adenotonsillectomy in the morning are less likely to have postoperative desaturation than those operated in the afternoon.
abstract: OBJECTIVE
  To determine, in a subset of children previously reported, if the time of day when adenotonsillectomy for severe obstructive sleep apnea syndrome (OSAS) was performed affected the incidence of postoperative respiratory complications.
  
  
  METHODS
  Children having adenotonsillectomy were included if they had a polysomnographic diagnosis of severe OSAS within six months prior to operation. Patients who met the inclusion criteria were grouped by the occurrence of postoperative desaturation into a saturated (SAT) and desaturated (deSAT) group. The charts of children in group deSAT were reviewed. The clock time of the surgical procedure was recorded and categorized as morning (AM) or afternoon (PM).
  
  
  RESULTS
  Eighty-eight patients met the inclusion criteria. There were 31 girls and 57 boys. The mean +/- SD age (yr) and weight (kg) were 4.6 +/- 2.9 yr and 20.8 +/- 14.5 kg respectively. There were 63 children in the SAT group and 25 in the deSAT group. Differences in age, weight and gender were not significant. The preoperative oxygen saturation (SaO2) nadir for the SAT and deSAT groups was 80.8 +/- 10.2% and 67.6 +/- 17.5% (P < 0.05) respectively. The preoperative obstructive apnea and hypopnea index was 15.8 +/- 10.2 and 35.7 +/- 34.6 events.hr(-1) (P < 0.05), respectively. Surgery in 63 (71.6%) children was performed in the AM. Univariate logistic regression identified PM surgery [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.7 to 12.6, P = 0.002] and a preoperative SaO2 nadir < 80% (OR 3.6, 95% CI 1.4 to 9.4, P = 0.009) as risk factors predicting postadenotonsillectomy desaturation.
  
  
  CONCLUSIONS
  Children with severe OSAS whose surgery is performed in the AM are less likely to desaturate following adenotonsillectomy than children whose surgery is performed in the PM.
authors.affiliation: Department of Anesthesia, Montreal Children's Hospital, Montreal, Quebec, Canada.
authors.forename: Albert
authors.initials: A
authors.lastname: Koomson
authors.forename: Isabelle
authors.initials: I
authors.lastname: Morin
authors.forename: Robert
authors.initials: R
authors.lastname: Brouillette
authors.forename: Karen A
authors.initials: KA
authors.lastname: Brown
mesh_terms: D000233:Adenoidectomy; D000701:Analgesics, Opioid / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009020:Morphine / Q000627:therapeutic use; D017286:Polysomnography; D011182:Postoperative Care; D011183:Postoperative Complications / Q000453:epidemiology*; D012140:Respiratory Tract Diseases / Q000209:etiology*; D018570:Risk Assessment; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D013997:Time Factors; D014068:Tonsillectomy
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine