Predictors of difficult intubation defined by the intubation difficulty scale (IDS): predictive value of 7 airway assessment factors / 대한마취과학회지

ABSTRACT

BACKGROUND: The intubation difficulty scale (IDS) has been used as a validated difficulty score to define difficult intubation (DI). The purpose of this study is to identify airway assessment factors and total airway score (TAS) for predicting DI defined by the IDS. METHODS: There were 305 ASA physical status 1-2 patients, aged 19-70 years, who underwent elective surgery with endotracheal intubation. During the pre-anesthetic visit, we evaluated patients by 7 preoperative airway assessment factors, including the following Mallampati classification, thyromental distance, head & neck movement, body mass index (BMI), buck teeth, inter-incisor gap, and upper lip bite test (ULBT). After endotracheal intubation, patients were divided into 2 groups based on their IDS score estimated with 7 variables normal (IDS or = 5) groups. The incidence of TAS (> 6) and high score of each airway assessment factor was compared in two groups odds ratio, confidence interval (CI) of 95%, with a significant P value 6), ULBT (class III), head & neck movement ( or = 25 kg/m2) and Mallampati classification (> or = class III) were respectively 13.57 (95% CI = 2.99-61.54, P 6) and ULBT (class III) are the most useful factors predicting DI.