Comparison of the success with two bending angles for lighted stylet intubation in children: A prospective randomised study

Background and Aim The bend angle of a lighted stylet is an important factor for successful orotracheal intubation. The aim of this study was to test the differences in the success of endotracheal intubation using lighted stylet with 70 degrees versus 90 degrees bend angles in children aged 4-6 years with normal airways. Methods A total of 136 children with normal airways required orotracheal intubation were enrolled and were randomly allocated to the 90 degrees or 70 degrees bend angle groups. The first-attempt success rate was assessed as the primary outcome. The intubation time, lighted stylet search time, lighted stylet withdrawal time, hemodynamic responses, and perioperative complications were recorded as secondary outcomes. Results All intubations were completed within three attempts (the 90 degrees group, 63/5/0; the 70 degrees group, 55/11/2). The first-attempt success rate was higher in the 90 degrees group than that in the 70 degrees group (92.6% [63/68 patients] versus 80.9% [55/68 patients], respectively; risk ratio, 1.15; 95% CI, 1.01-1.31; p = .04). Esophageal entry occurred in nine of 83 intubation attempts in the 70 degrees group and two of 73 intubation attempts in the 90 degrees group (risk ratio, 1.09; 95% CI, 1.01-1.19; p = .04). The intubation time and the lighted stylet search time were significantly shorter in the 90 degrees group than that in the 70 degrees group (intubation time: 12.2 +/- 2.0 s versus 14.9 +/- 2.6 s, respectively; mean difference, 2.65; 95% CI, 1.87-3.43; p < .01; effect size, 1.16; lighted stylet search time: 5.4 +/- 1.0 s versus 8.0 +/- 1.6 s, respectively; mean difference, 2.66; 95% CI, 2.21-3.12; p < .01; effect size, 1.95). Conclusions Lighted stylet intubation with a 90 degrees bend angle improved the first-attempt success rate and reduced esophageal intubation in children aged 4-6 years with normal airways.