Correlation between predictors of difficult mask ventilation and its grading using a risk score

Abstract

Background: Maintenance of airway patency and oxygenation are the main objectives of face mask ventilation. Preoperative prediction can reduce the incidence of unanticipated difficult mask ventilation (DMV). Aim of Study: The aim of this study was to evaluate the correlation between predictors of DMV and its grading using a risk score. Study Setting and Design: This was an observational study approved by the Institutional Ethics Committee in a tertiary care hospital between 2020 and 2021. Patients and Methods: A total of 110 adult patients scheduled for elective surgery under general anaesthesia were studied. A detailed preoperative airway assessment was done to identify and risk score for seven standard predictors of DMV (male gender, age >55 years, body mass index ≥30 kg/m2, obstructive sleep apnoea [STOP-BANG score], edentulous state, modified Mallampati class and presence of beard). The risk score was correlated with the grading of mask ventilation in the operation theatre performed using the four-point scale as described by Han et al. Results: A statistically significant association was found with standard predictors such as male gender, obstructive sleep apnoea (STOP-BANG score) and the total preoperative risk score with the grading of mask ventilation (P < 0.05 for all). Additional risk factors found statistically significant were interincisor distance, thyromental distance, neck circumference, receding mandible, mandibular jaw protrusion, restricted neck movements, buck teeth and submucosal fibrosis. Conclusion: Prediction of DMV with preoperative risk score can lead to better anticipation of difficult airway management. Appropriate anticipatory airway management could potentially decrease the incidence of failed ventilation and resultant hypoxia.