Clinical predictors of difficult laryngeal exposure.

AIM OF THE STUDY To identify the preoperative clinical factors those contribute to difficult laryngeal exposure in patients undergoing microlaryngoscopy. INTRODUCTION Microlaryngoscopy or suspension laryngoscopy has paved the pathway for endolaryngeal surgeries be it for therapeutic or diagnostic procedures. This is done using a rigid laryngoscope. It is used to expose the larynx to access and treat vocal fold lesions that cause dysphonia / hoarseness of voice. Commonly, the rigid laryngoscope is placed through oral cavity and the larynx is exposed under general anesthesia without difficulty. Despite a significant amount of literature discussing approaches to difficult laryngeal exposure (DLE) in anaesthesia there remains a lack of consensus in describing reproducible parameters or physical findings associated with DLE. OBJECTIVES 1.To find preoperative clinical predictors for difficult laryngeal exposure. 2. To define a simplified grading system for difficult laryngeal exposure. SUMMARY 1. Laryngeal exposure for microlaryngoscopy correlates well with that for intubation: MCLS grade more than 2a has an odds ratio (OR) of 12 in predicting DLE 2. Limited neck extension of less than 19.5 degrees has an odds ratio of 4 for predicting DLE 3. Neck circumference of more than 34.25 has an odds ratio of 4 in predicting DLE. 4. Of the 117 cases there were only seven cases with complications. Of these seven, six had a difficult laryngeal exposure CONCLUSION The predictors of Difficult Laryngeal Exposure were found to be Modified Cormack Lahane Score more than 2a, neck extension of less than 19.5 degrees and neck circumference of more than 34.25 cms. The proposed grading system is a simple tool which can be employed in any set up by otolaryngologists in preparation for microlaryngoscopy