Comparison of McGRATH MAC and Macintosh laryngoscopes for double-lumen endotracheal tube intubation by anesthesia residents: a prospective randomized clinical trial.

Study Objective: This study aimed to compare the utility of McGRATH MAC (McG) and Macintosh (McL) laryngoscopes for double-lumen endotracheal tube intubation in patients undergoing elective surgery.

Design: Randomized clinical trial.

Setting: Operating room.

Patients: Fifty adult patients scheduled for elective surgery under 1-lung ventilation with American Society of Anesthesiologists physical status 1 to 3.

Interventions: Double-lumen endotracheal tube intubation was performed with the McG (McG group; 25 patients) or conventional McL (McL group; 25 patients) laryngoscope by anesthesia residents.

Measurements: The number of attempts to successful intubation, intubation time, percentage of glottis opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed.

Main Results: The total numbers of intubation attempts were 1 (McG group, 24 patients; McL group, 16 patients), 2 (McG group, 1 patient; McL group, 8 patients), and 3 (McG group, 0 patient; McL group, 1 patient), with significant differences between the two groups (P = .018). Intubation time was significantly shorter in the McG group compared with the McL group (McG: 17.1 ± 4.6 seconds vs McL: 20.8 ± 5.9 seconds, P = .026). The percentage of glottis opening score was significantly higher in the McG group compared with the McL group (McG: 88.4% ± 13.7% vs McL: 71.4% ± 20.4%, P = .004).

Conclusions: The McG demonstrated a better intubation profile compared with the McL, possibly due to its ease of use for double-lumen endotracheal tube intubation. Clinical Trial registry number: UMIN000014636.