Comparison of the intubation time between McGRATHTM MAC size 1 and size 2 blades for infants: an observational study

Abstract

Purpose: This study aimed to determine whether the McGRATHTM MAC size 1 blade, which has become available in recent years, reduced the tracheal intubation time in infants compared to that of the McGRATHTM MAC size 2 blade. Methods: This single-center, retrospective, observational study included patients aged < 1 y who underwent cardiac surgery under general anesthesia. Cases in which the McGRATHTM MAC size 2 blade was used were classified as MAC2 and those in which the McGRATHTM MAC size 1 blade was used as MAC1. The primary endpoint was the difference in time required for tracheal intubation. The results were adjusted for confounding factors (patient weight, career of intubation provider, and risk of difficult tracheal intubation). Other variables included the first successful tracheal intubation rate, number of tracheal intubations, Cormack classification, and adverse events during tracheal intubation. Results: In total, 94 patients met the inclusion criteria, 26 met the exclusion criteria¸ thus 68 patients were analyzed. The median time to tracheal intubation was significantly shorter for MAC1 than for MAC2. (23.5 s vs. 27.0 s; hazard ratio, 1.79; 95% confidence interval, 1.08, 2.95). The adjusted time to tracheal intubation was also significantly shorter in the MAC1 group than in the MAC2 group (hazard ratio, 1.71; 95% confidence interval, 1.00, 2.89). No secondary endpoint showed significant differences. Conclusions: For tracheal intubation in cardiac surgery in infants, using the McGRATHTM MAC size 1 blade may reduce the tracheal intubation time compared to the McGRATHTM MAC size 2 blade.