Postoperative laryngeal morbidity and intubating conditions using the McGRATH™ MAC videolaryngoscope with or without neuromuscular blockade: a randomised, double-blind, non-inferiority trial.

Tracheal intubation without neuromuscular blockade may be associated with worse intubating conditions and increased laryngeal morbidity. We hypothesised that tracheal intubation using the McGRATH™ MAC videolaryngoscope would not increase postoperative hoarseness, even without neuromuscular blockade. In this prospective, randomised, parallel-group, double-blind, non-inferiority trial, 248 patients were randomly assigned to tracheal intubation with or without neuromuscular blockade using rocuronium. Hoarseness and sore throat were evaluated at 24 h and 48 h postoperatively. The primary outcome was the incidence of hoarseness at 48 h postoperatively with a pre-defined non-inferiority margin of 10%. Hoarseness at 48 h did not differ between the non-paralysed group and the paralysed group (8.1% vs. 13.6%; absolute difference: -5.4%; 95%CI: -13.3 to 2.4). Also, no significant differences were found between the two groups for hoarseness at 24 h (22.8% vs. 27.1%) or for sore throat at 24 h (12.2% vs. 9.3%) and 48 h postoperatively (1.6% vs. 0.8%). Although more patients in the non-paralysed group showed an adducted position of the vocal cords (29.3% vs. 0%), there were no significant group differences in the ease of laryngoscopy (96.7% vs. 98.3%), Cormack grade laryngeal view 1 (97.6% vs. 96.6%) or first-pass success rate (100% vs. 100%). We conclude that when using the McGRATH MAC videolaryngoscope for tracheal intubation, the incidence of postoperative hoarseness was not inferior if neuromuscular blockade was avoided.