Predictability of difficult laryngoscopy in patients with long-term diabetes mellitus.

The laryngoscopic conditions of 62 diabetic patients who underwent renal transplantation or vitrectomy were studied. Anaesthesia was induced with fentanyl and a sleep dose of thiopentone. Conditions for direct laryngoscopy after 0.1 mg/kg vecuronium were scored from 0 to 3 (easy-very difficult). All patients gave their palm prints after operation which were scored: 0, phalangeal areas completely visible; 1, phalangeal areas partly visible; 2, phalangeal areas hardly visible; 3, only fingertips printed. The incidence of difficult laryngoscopy was 31%. The higher the scores in the palm test, the more difficult was the laryngoscopy. The correlation coefficient between these two factors was r = 0.6 (p less than 0.001). Our study shows that joint rigidity possibly caused by tissue glycosylation may also involve laryngeal and cervical areas resulting in a strenuous laryngoscopy. A defective palm print is a warning sign for difficult laryngoscopy.