Comparison of glottic view and ease of orotracheal intubation with Macintosh and McCoy laryngoscopes in anaesthetised adult patients

Background and aims: This study is aimed at comparing glottic view and ease of intubation with Macintosh and McCoy^TM laryngoscopes in adult patients.

Methods: One hundred forty consenting patients undergoing elective surgery requiring orotracheal intubation were randomly assigned to two groups for assessment of glottic view and ease of intubation. Cormack-Lehane (CL) glottic view, ease of intubation, laryngoscopy time and intubation time were recorded.

Results: All recruited patients completed the study, with a single attempt for successful intubation. Demographic profile was comparable between groups. Glottic view represented as CL grade (Macintosh laryngoscope- grade 1 among 100 patients, 2a in 26, 2b in 12 and 3a in 2 patients; McCoy^TM laryngoscope- grade 1 in 105, 2a in 20, 2b in 13 and 3a in 2 patients), requirement of additional manoeuvres like optimal external laryngeal manipulation (OELM)/use of lever for best glottic view (OELM in 40 patients, lever in 35 patients), ease of intubation (Macintosh laryngoscope- grade 1 in 49 patients, grade 2 in 21 patients; McCoy^TM laryngoscope- grade 1 in 53 patients, grade 2 in 17 patients), mean laryngoscopy time (6.02 ± 1.91 s with Macintosh and 6.65 ± 2.09 s with McCoy^TM laryngoscope) and mean intubation time (15.24 ± 3.01 s with Macintosh and 16.09 ± 3.42 s with McCoy^TM laryngoscope) were comparable between laryngoscopes.

Conclusion: In adult patients with essentially normal airway, Macintosh and McCoy^TM laryngoscopes provide similar glottic view and ease at intubation, with comparable time required for laryngoscopy and intubation when performed by an experienced anaesthesiologist.