Background: Pre-operative evaluation is a cornerstone in identifying patients with a risk of difficulty in intubation. Thyromental distance (TMD) is the most commonly used predictor of difficult intubation. However, it's not a reliable indicator of difficulty during intubation because it differs with patients' body & size proportion. The present study was done for the evaluation of the ratio of height to thyromental distance (RHTMD) and ratio of height to sternomental distance (RHSMD) as difficult airway predictors.Methods: Data was taken from 400 consecutive patients posted for the need for anesthesia with intubation during surgery. Preoperatively examination of RHTMD and RHSMD was done. Difficulty during intubation has been explained in this current study with Cormack and Lehane grade 3 or 4. The positive and negative predictive values, as well as sensitivity and specificity of individual tests, were calculated as per the recognized formula.Results: The study enrolled 400 patients, which include a maximum number of participants (138 [34.5%]) from the 41-50 year age group. On analyzing RHTMD and RHSMD, the former was found to have a better predictive value than RHSMD (p=0.001). RHTMD & RHSMD was found to have 62.5% & 37.50% sensitivity, respectively. RHTMD was found to have better specificity, positive & negative predictive values, and accuracy than RHSMD. Conclusion: RHTMD was observed to have superior precision in anticipating difficulty in intubation compared to RHSMD.

Background: The usefulness of modified Cormack-Lehane scoring system (MCLS) used for laryngoscopy was introduced and used extensively Western population. This study was undertaken for evaluation of modified Cormack-Lehane scoring system in Indian population. Methods: 198 patients of more than 18 years of age requiring tracheal intubation were evaluated with preoperative airway predictors, the modified Mallampati test and thyromental distance (TMD). Result: The larynx was difficult to visualize (Cormack and Lehane grades IIIB and IV) in 18 / 198 (9.09 %) patients. No failed tracheal intubations occurred in any of the 18 cases. Conclusion: The Mallampati classification was associated with good predictive value for 3B and 4 of modified Cormack-Lehane scoring system. The MCLS better delineates the difficulty experienced during laryngoscopy than the original Cormack-Lehane grading.