Difficult laryngoscopy and intubation using thyromental distance during: Operative assessment of patients

Abstract

The airway begins functionally at the nares. The septum divides the nasal cavity into two narrow cavities. The nasal cavity extends from the external nares to the posterior choanae, where it becomes continuous with the nasopharynx. Vertically it extends from the palate to the cribriform plate. Each half has a floor, roof, a lateral wall and a medial septum wall. The lateral wall is uneven because of the three bony projection known as conchae. 300 consecutive (apparently normal) American Society of Anaesthesiologist grade 1 &2 adult patients undergoing elective surgical procedures under general anaesthesia with endotracheal intubation at Medical college and teaching Hospital were the subjects in this study. Thyromental distance<6cm was considered as predictor of difficult intubation. There were 16 cases out of 300 patients (5.3%) belong to thyromental distance less than 6cms.