Comparison of modified Mallampati test with and without phonation for prediction of difficult laryngoscopy and intubation among adult surgical patients: cross-sectional study

Background: The modified Mallampati test (MMT) is one of the most widely used airway assessment tests, for predicting laryngoscopy and tracheal intubation difficulty. The MMT without phonation is routinely performed, but its specificity in identifying easy intubation is controversial. This study aimed to compare the MMT with and without phonation in predicting difficult laryngoscopy and tracheal intubation in adult elective surgical patients who underwent general anesthesia. Materials and methods: An institution-based cross-sectional study was performed on 258 adult elective surgical patients who required tracheal intubation. A systemic random sampling technique was employed to select study participants, and the MMT, with and without phonation, was performed during the preoperative assessment. A laryngoscopic view was recorded at the time of tracheal intubation and classified as easy or difficult for tracheal intubation. The collected data were entered into Epi-info and analyzed using the statistics package of social science software version 26. Statistical significance was defined as a P value of less than 0.05. This study used specificity, sensitivity, accuracy, and positive and negative predictive values as the statistical measures. Results: The prevalence of laryngoscopy and intubation difficulties was observed to be 13.6% and 10.5%, respectively. MMT conducted without phonation had the higher sensitivity for predicting difficult laryngoscopy and intubation, than MMT with phonation. But MMT performed with phonation had higher specificity for identifying easy intubation, than MMT without phonation. Conclusion: The MMT with phonation has higher accuracy, specificity, and positive predictive value for difficult laryngoscopy and intubation than the non-phonation approach. MMT combined with phonation can be used as an alternative assessment tool to predict difficult airways.