The Performance of the Intubation Difficulty Scale among Obese Parturients Undergoing Cesarean Section.

Background. There have not yet been any studies to validate the intubation difficulty scale (IDS) in obese parturients. Objectives of this study were to determine the performance of the IDS in defining difficult intubation (DI) and to identify the optimal cutoff points of the IDS among obese parturients. Methods. This was a prospective observational study. Parturients with a body mass index ≥ 30 kg/m2 who underwent cesarean section utilizing endotracheal intubation were enrolled. The intubating performers were asked to assess the difficulty of endotracheal intubation and categorize it as easy, somewhat DI, and DI. Main Results. A total of 517 parturients were recruited with a mean BMI of 33.9 kg/m2. The incidence of some degree of DI was 14.5%. The area under the receiver operating characteristic curves of the IDS for detecting somewhat DI and DI was 1.0. The optimal cutoff point to define somewhat DI was ≥3 and DI was ≥5, which both had sensitivity and specificity of 100%. Conclusions. The IDS scoring is a good tool for defining DI among obese parturients. The IDS scores of ≥3 and ≥5 are the optimal cutoff points to define somewhat DI and DI, respectively.