Incidence and Predictors of Difficult Mask Ventilation in High-Risk Adult Population Scheduled for Elective Surgery: A Prospective Observational Study.

Abstract

IntroductionMask ventilation is one of the key components in the management of airway during general anaesthesia, particularly when laryngoscopy is challenging. Adequate mask ventilation provides anaesthesiologists a safe time in case of unanticipated or anticipated difficult airway situations. The aim of this study was to determine the incidence of difficult bag-mask ventilation and intubation in patients having three or more predictors for difficult mask ventilation (DMV) in adult patients scheduled for elective surgery under anaesthesia.MethodsA total of 294 patients requiring endotracheal intubation for elective surgical procedure having three or more risk factors were evaluated for the presence of difficulty in bag-mask ventilation and intubation by the anaesthesiologist. Chi-square test or Fisher's exact test and a multivariable stepwise logistic regression model were performed to identify predictors of DMV. Crude and adjusted odds ratio with 95% confidence interval were reported.ResultsIn this study, the average age of the patients was 53.59±13.32 years with a 2:1 male-to-female ratio. DMV and difficult intubation (DI) were observed in 31.6% and 3% of patients, respectively. Multivariate analysis identified history of snoring, BMI (>35 kg/m2), presence of beard and Mallampati III or IV as independent predictors for DMV. Patients with multiple factors (≥3 factors) had a threefold (OR=2.57) increased risk of difficulty in mask ventilation and a nearly fivefold (OR=4.63) increased risk of difficulty with intubation.Conclusion In our study, the incidence of DMV was observed in 93 (31.6%) patients and DI was found in 9 (3%) patients. A simple DMV risk score may help to predict DMV better, potentially improving safety during difficult airway management, decreasing morbidity and mortality associated with it.