title: Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance.
abstract: The objective of this study was to systematically determine the diagnostic accuracy of bedside tests for predicting difficult intubation in patients with no airway pathology. Thirty-five studies (50,760 patients) were selected from electronic databases. The overall incidence of difficult intubation was 5.8% (95% confidence interval, 4.5-7.5%). Screening tests included the Mallampati oropharyngeal classification, thyromental distance, sternomental distance, mouth opening, and Wilson risk score. Each test yielded poor to moderate sensitivity (20-62%) and moderate to fair specificity (82-97%). The most useful bedside test for prediction was found to be a combination of the Mallampati classification and thyromental distance (positive likelihood ratio, 9.9; 95% confidence interval, 3.1-31.9). Currently available screening tests for difficult intubation have only poor to moderate discriminative power when used alone. Combinations of tests add some incremental diagnostic value in comparison to the value of each test alone. The clinical value of bedside screening tests for predicting difficult intubation remains limited.
authors.affiliation: Department of Anesthesia, Nippon Medical School Chiba Hokusoh Hospital, Kamagari, Chiba, Japan. qzx02115@nifty.com
authors.forename: Toshiya
authors.initials: T
authors.lastname: Shiga
authors.forename: Zen'ichiro
authors.initials: Z
authors.lastname: Wajima
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Inoue
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Sakamoto
mesh_terms: D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods; D009055:Mouth / Q000033:anatomy & histology; D009333:Neck / Q000033:anatomy & histology; D009960:Oropharynx / Q000033:anatomy & histology; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity