title: Clinical predictors in obstructive sleep apnea patients with computer-assisted quantitative videoendoscopic upper airway analysis.
abstract: OBJECTIVE
  To identify the clinical predictors and assist surgeons in their clinical management of obstructive sleep apnea (OSA). A prospective study with a new approach to analyze the static and dynamic upper airway morphology between patients with OSA and normal subjects.
  
  
  METHODS
  Quantitative computer-assisted videoendoscopy (validated with upper airway magnetic resonance imaging) was performed in 49 (43 males, 6 females) patients with OSA and compared with 39 (22 males, 17 females) controls (apnea-hypopnea index [AHI] < 5). Absolute cross-sectional areas and transverse and longitudinal diameters at the retropalatal and retrolingual levels were measured during end of quiet respiration and during Mueller's maneuver in the erect and supine positions, allowing us to study static and dynamic morphology (collapsibility) of the upper airway. Three thousand seven hundred forty-four (3,744) parameters were analyzed.
  
  
  RESULTS
  In males, retropalatal and retrolingual areas during Mueller's maneuver in the supine position of 0.7981 cm (relative operating characteristics [ROC] = 0.9284, positive pressure ventilation [PPV] = 86.05%, negative pressure ventilation [NPV] = 84.62%) and 2.0648 cm (ROC = 0.8183, PPV = 76%, NPV = 83.33%), respectively, were found to be good predictors/cut-off values for OSA. The retropalatal area measured in the supine position (AS1 mol/L) and collapsibility of the retropalatal area in the supine position (CAS1) were found to have significant correlations with severity of OSA. In females, the areas measured during Mueller's maneuver in the supine position of 0.522 cm at the retropalatal level (ROC = 1, 100% PPV and NPV) and the transverse diameter at the retrolingual level during erect Mueller's maneuver of 1.1843 cm (ROC = 0.9056, PPV = 100%, NPV = 83.33%) were found to be predictive. All measurements at the retropalatal level and in the supine position had higher predictability. Area measurements obtained during Muller's maneuver were more predictive (ROC > 0.9910) than resting measurements (ROC >0.8371). Several sex and anatomic-site specific formulas with excellent predictability (ROC close or equal to 1) were also devised.
  
  
  CONCLUSIONS
  Upper airway Mueller's studies are predictive and useful (independent samples t test/Mann-Whitney U test, ROC) in identifying patients with OSA. With these sex and anatomic-site specific OSA predictors/formulas and this innovative clinical method, we hope to assist other surgeons with quantitative clinical diagnosis, assessment, surgical planning, and outcome assessment tools for OSA patients.
authors.affiliation: Division of Otolaryngology, Changi General Hospital, Singapore, Republic of Singapore. hsuponpoh@yahoo.com
authors.forename: Pon Poh
authors.initials: PP
authors.lastname: Hsu
authors.forename: Barrie Yau Boon
authors.initials: BY
authors.lastname: Tan
authors.forename: Yiong Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Hin Ngan
authors.initials: HN
authors.lastname: Tay
authors.forename: Peter Kok Sun
authors.initials: PK
authors.lastname: Lu
authors.forename: Robin L
authors.initials: RL
authors.lastname: Blair
mesh_terms: D003430:Cross-Sectional Studies; D003936:Diagnosis, Computer-Assisted; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009296:Nasal Cavity / Q000033:anatomy & histology*; D010614:Pharynx / Q000033:anatomy & histology*; D017286:Polysomnography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*; D014743:Videotape Recording