title: Usefulness of sleep endoscopy in predicting positional obstructive sleep apnea.
abstract: OBJECTIVE
  The aim of the study was to (1) evaluate whether position affects drug-induced sleep endoscopy (DISE) findings in positional and nonpositional patients and (2) determine which areas of the upper airway obstruct in different body positions.
  
  
  METHODS
  Prospective, case-controlled study.
  
  
  METHODS
  Academic tertiary care center.
  
  
  METHODS
  Twenty-two patients with obstructive sleep apnea (OSA) were enrolled. Two groups were individually recruited to make 11 consecutive patients with positional OSA and 11 consecutive patients with nonpositional OSA. Positional OSA was defined by nonsupine 50% reduction in apnea-hypopnea index. DISE was performed with patients in both lateral and supine sleep positions. Upper airway collapse was compared between the sleep positions and between the 2 groups.
  
  
  RESULTS
  Most patients (77%) demonstrated multilevel obstruction on DISE. Nearly all patients with positional OSA (91%) had at least a partial improvement in collapse while in the lateral sleep position. Most of the reduction in collapse involved the tongue base and epiglottis (P < .05). Sleep position did not significantly alter the upper airway morphology of patients with nonpositional OSA. Apnea-hypopnea index and body mass index were not significantly different between the 2 groups.
  
  
  CONCLUSIONS
  Sleep position can change upper airway morphology on DISE, particularly positional OSA patients. Hypopharyngeal collapse was the primary site that improved with change in position. DISE in multiple sleep positions should be considered as part of a minimally invasive approach to surgical therapy of OSA.
authors.affiliation: Bobby R. Alford Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Victores
authors.forename: John
authors.initials: J
authors.lastname: Hamblin
authors.forename: Janet
authors.initials: J
authors.lastname: Gilbert
authors.forename: Christi
authors.initials: C
authors.lastname: Switzer
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Takashima
mesh_terms: D000328:Adult; D000771:Anesthesia, Intravenous / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D015992:Body Mass Index; D016022:Case-Control Studies; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D011187:Posture / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012890:Sleep / Q000187:drug effects*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology
chemical_list: D018686:Anesthetics, Intravenous
keywords: drug-induced sleep endoscopy; obstructive sleep apnea; positional obstructive sleep apnea