The Comparative Study of Mallampati Classification and Laryngoscopic Grading for Airway Assessment

Abstract

Background and Objectives: Tracheal intubation is a safe and practical way currently used in airway management. In this regard, preanesthesia airway assessment and prediction of probable difficult laryngoscopy and intubation remained a basic and important problem. Several predictive methods, including mallampati score were used for assessment of airway. The aim of this study was to evaluatet effectiveness of mallampatti's test on laryngoscopic grading. Materials and Methods: In a prospective, randomized, double blind Study 500 patients undergoing surgery were evaluated to compare mallampati classes with grading of laryngoscopy. The incidence of mallampati classes from I to IV and laryngoscopic grading from 1-4 were determined alone and laryngoscopic grading were compared in each of the mallampati classes separatively. Statistical analysis was preformed using Fisher's exact test. Results: In this study the distribution of laryngoscopic grading in the different classes of mallampatti and the sensitivity of mallampati in prediction of laryngoscopic grading for different classes were determined. There was significant difference in distribution of laryngoscopic grading in the different classes of mallampati score (P<0.001). The results between sex groups in women were statistically Signifiant. (In men P=0.110 and in women P=0.001). But in comparing the sex groups with each other, there was not any significant differences (P=0.05). In addition the Specificity of the test, the accuracy, positive predictive value and negative predictive value were 17.02%, 90.4%, 47.05% and 91.09%, respectively. Also the sensitivity of mallampati score in diagnosis of difficult laryngoscopy was 47.05%. Conclusion: Difficulty in managing of the airway is the most important cause of major anesthesia related morbidity and mortality. Therefore the sensitivity for mallampati score to detect laryngoscopic grading was determined. According to the results, it is better to use multiple tests simultaneously for evaluating and predicting of difficulty in airway.