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

Abstract

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 ± 1.91s with Macintosh and 6.65 ± 2.09s with McCoy TM laryngoscope) and mean intubation time (15.24 ± 3.01s with Macintosh and 16.09 ± 3.42s 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.