A prospective comparison between Mallampati Classification & Friedmans Tongue Positions for airway assessment and their correlation with Cormac-Lehane grading.

Difficulty in airway management is an important cause of morbidity and mortality in anesthetic practice. Unanticipated difficult intubation can be challenging to anesthesiologists, and numerous investigators have attempted to predict difficult intubation by using various bedside tests.

The Modified Mallampati Class (MPC) score, thyromental distance (TMD), sternomental (SM) distance, inter incisor gap, BMI, and ability to flex and extend the cervical spine, neck circumference, upper lip bite test, are some of the widely recognized as tools for predicting difficult intubation.

 The Mallampati grade was first developed by Seshagiri Mallamapati in 1985. He was an anesthesiologist who sought to predict the risk of difficult intubation based on mouth opening. Using a simple three-grade classification based on whether Mallampatti grade could visualize the tonsillar pillars, uvula, and soft palate, he showed correlation between Mallampatti grade and view of the airway on direct laryngoscopy. Samsoon and Young reported a modification of the Mallampati grade when even the soft palate was difficult to visualize and they added an additional classification, grade 4, where only the hard palate was able to be visualized. This modification is called Modified Mallampatti Class (MPC) grade.

 The Friedman Tongue Position (FTP) was introduced and used as a tool by pulmonologists to predict the severity of Obstructive Sleep Apnoea (OSA). FTP is the evaluation of the tongue’s position relative to the tonsils/pillars, uvula, soft palate, and hard palate. It is a test known to predict difficult airway in OSA patients.

While the Mallampati system has 3 grades and evaluates the palate with the tongue protruded, FTP evaluates the palate with the tongue in a neutral position inside the mouth. Furthermore, FTP is assigned on a scale from I to IV, and FTP II is split into IIa and IIb. FTP I allows the observer to visualize the entire uvula and tonsils or pillars. FTP IIa allows visualization of the uvula but the tonsils are only partially seen. FTP IIb allows visualization of the complete soft palate down to the base of the uvula, but the uvula and the tonsils are not seen. FTP III allows visualization of some of the soft palate but the distal soft palate is eclipsed. FTP IV allows visualization of the hard palate only.

 The MPC is a test that is used universally by anaesthesiologists to screen any airway for predicting difficulty in intubation. During intubation, the tongue remains inside the oral cavity, as opposed to the condition simulated during the MPC. As a result, it may not be the most accurate measure of predicting difficult airway. Our study hypotheses that since the FTP allows us to evaluate the oral cavity in the condition that mimics the situation during intubation, it would be just as good as the MPC in predicting the difficult airway.