A double bending lightwand can provide more successful endotracheal intubation in patients with a short thyromental distance: a prospective randomised study

Background and objective This study assessed the efficacy of endotracheal intubation using a double bending lightwand in patients with an anticipated difficult airway because of a short thyromental distance. Methods On the basis of the shape of the lightwand used, 68 patients with a thyromental distance of less than 65 mm undergoing general anaesthesia were randomly allocated to one of two groups. In the conventional bending group (n = 34), the lightwand was bent at 6.5 cm from the distal end to 90° angle. In the double bending group (n = 34), the lightwand was bent 30° at 15 cm from its tip in addition to the conventional bending. The ease of insertion was assessed by the lightwand search time and success rate at the first attempt. Post-operative complications, if any, were noted. Results The success rate of intubation at the first attempt was higher for the double bending group (94 vs. 74%, P < 0.05). The search time was significantly shorter in the double bending group than the conventional bending group (10 ± 6 vs. 15 ± 8 s, P < 0.01). Mean blood pressure and heart rate increased after intubation in both groups (P < 0.05), but there were no significant differences between the groups. The incidence of post-operative sore throat and mucosal bleeding was not significantly different between the groups. Conclusion We conclude that the double bending lightwand is associated with a greater success rate of intubation in patients with an anticipated difficult airway because of a short thyromental distance.