Comparison of Mallampati test with and without phonation for prediction of difficult airways on adult patient (Prospective observational study)

Abstract

Abstract Background Mallampati test is one of the most widely used airway tests to predict laryngoscopy and tracheal intubation difficulties. The Mallampati test without phonation is routinely practiced, but its sensitivity in predicting difficult intubation is controversial. Objective To compare the Malampati test with and without phonation in predicting difficult laryngoscopy and tracheal intubation among adult elective surgical patients who underwent general anaesthesia. Method A hospital based cross-sectional study was performed on 258 adult elective surgery patients who required tracheal intubation at Tikur Anbessa specialized hospital. A systemic random sampling technique was employed to select study participant and the Mallampati test with and without phonation was performed during preoperative assessment. Then a laryngoscopic view was recorded at the time of tracheal intubation, and Mallampati test grades I and II were classified as easy, while grades III and IV were classified as difficult for tracheal intubation. The data was entered by Epi info and analysed with the statistics package of the social science software version 26. Statistical significance was defined at p-value of less than 0.05. This study used specificity, sensitivity, accuracy, and positive and negative predictive values as statistical measures. Result The prevalence of laryngoscopy and intubation difficulty was 13.6% and 10.5%, respectively. Mallampati test without phonation had a sensitivity of 82.9% and a specificity of 79.1% for difficult laryngoscope. And it had a sensitivity of 88.9%, a specificity of 87% for difficult intubation. MMT with phonation had a sensitivity of 74.3% and a specificity of 91.9% for difficult laryngoscopy and it had a sensitivity of 77.8% and specificity of 90% for difficult intubation. Conclusion Based on our study results, MMT with phonation has higher accuracy, specificity, and PPV in the prediction of difficult laryngoscopy and intubation than the non-phonation approach.