Ultrasound Guided Airway Parameters for Predicting Difficult Mask Ventilation: A Prospective Observational Study

Objective: Face mask ventilation is the method of ventilation in all patients before securing definitive airway.Airway examinations are based on history and physical examinations to predict difficult mask ventilation (DMV) or laryngoscopy.Ultrasound being rapid bed side tool has gained popularity in airway management, point of care ultrasound can be used as a clinical tool for evaluating airways.We attempted to assess the correlation between difficult mask ventilation and ultrasound assessment of distance between lingual arteries (DLA), tongue thickness (TT) and lateral pharyngeal wall thickness (LPWT) after standard induction of anaesthesia.Method: Overall, 264 patients scheduled for elective surgery requiring general anaesthesia were included.In preoperative holding area, ultrasonographic assessment of DLA, TT and LPWT were measured.After standard induction, mask ventilation is attempted and graded according to Han's grading.Mask ventilation was considered as difficult for Han's grade 2 and above.Results: Out of 264 patients, 230 (87.1%) had easy mask ventilation, while 34 (12.9%)experienced difficult mask ventilation.Pre induction values of DLA more than 2.52 cm had sensitivity of 47.06%, specificity of 76.09% with area under receiver operating characteristics (AUROC) of 0.641 and P value 0.004.Tongue thickness more than 4.67 cm had sensitivity of 44.12%, specificity of 83.04% with AUROC of 0.636 and P value