title: Difficult laryngoscopy: incidence and predictors in patients undergoing coronary artery bypass surgery versus general surgery patients.
abstract: OBJECTIVE
  Cardiac surgery patients might have a higher incidence of difficult laryngoscopy than the general population because of older age, dental problems, and obesity. The authors estimated the incidence and predictors of difficult laryngoscopy in coronary artery bypass surgery patients.
  
  
  METHODS
  Prospective, controlled study.
  
  
  METHODS
  University setting.
  
  
  METHODS
  Patients undergoing coronary artery bypass or general surgery.
  
  
  METHODS
  Two hundred consecutive patients undergoing coronary artery bypass graft and 444 general surgery patients, all aged >40 years, were compared for the incidence and predictors of difficult laryngoscopy, defined as a grade III or IV view.
  
  
  RESULTS
  Predictors of difficult laryngoscopy were considered mouth opening <4 cm, limited cervical mobility, thyromental distance <6 cm, protruding or partially missing upper teeth, and Mallampati classes 3 and 4. More cases of difficult laryngoscopy were recorded in cardiac patients (10% v 5.2%, p <0.023). The cardiac patients were older, mostly men, and belonged to ASA III-IV risk classes. Mallampati classes 3 and 4 were more frequent in the control group. With univariate analysis, difficult laryngoscopy correlated with 7 variables: older age, ASA-IV risk class, protruding or partially missing upper teeth, limited mouth opening, limited neck movement, thyromental distance <6 cm, and diabetes mellitus. Multivariate analysis adjusted for propensity score identified older age (odds ratio = 1.05/yr, 95% confidence interval = 1.005-1.09, p < 0.03) and limited neck movement (odds ratio = 9.5, 95% confidence interval = 2.2-41, p < 0.003), but not cardiac surgery per se, as independent predictors of difficult laryngoscopy.
  
  
  CONCLUSIONS
  Difficult laryngoscopy was more frequent in cardiac surgery patients (10% v 5.2%). Older age and limited neck movement, but not cardiac surgery per se, were independent predictors of difficult laryngoscopy.
authors.affiliation: Department of Anesthesia, Pediatric Cardiac Surgery Unit, Wolfson Medical Center, Holon, Tel-Aviv, Israel. tezri@netvision.net.il
authors.forename: Tiberiu
authors.initials: T
authors.lastname: Ezri
authors.forename: Marian
authors.initials: M
authors.lastname: Weisenberg
authors.forename: Vadim
authors.initials: V
authors.lastname: Khazin
authors.forename: Deeb
authors.initials: D
authors.lastname: Zabeeda
authors.forename: Lior
authors.initials: L
authors.lastname: Sasson
authors.forename: Arie
authors.initials: A
authors.lastname: Shachner
authors.forename: Beniamin
authors.initials: B
authors.lastname: Medalion
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D018849:Controlled Clinical Trials as Topic; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D007828:Laryngoscopy; D007830:Larynx / Q000033:anatomy & histology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000033:anatomy & histology / Q000473:pathology; D015999:Multivariate Analysis; D009333:Neck / Q000033:anatomy & histology / Q000473:pathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013223:Statistics as Topic; D014070:Tooth / Q000033:anatomy & histology / Q000473:pathology; D016896:Treatment Outcome