Comparison of the Efficacy of Macintosh Laryngoscope Versus Airtraq Videolaryngoscope for Visualization of Laryngeal Structures at the End of Thyroidectomy: A Randomized Control Study.

Abstract

To compare the efficacy of conventional Macintosh laryngoscope with Airtraq videolaryngoscope for visualization of laryngeal structures to rule out recurrent laryngeal nerve injury at the end of thyroidectomy. This randomized double-blind control study was conducted following IEC-Human approval, prospective CTRI registration and written informed consent from participants. Patients of either sex, aged 18-65 years, ASA grade I/II, scheduled for thyroidectomy under GA were included. Group DL underwent direct laryngoscopy using Macintosh blade whereas group VL underwent laryngoscopy using Airtraq® videolaryngoscope. CL(Cormack-Lehane) grade of laryngeal view, time taken to achieve optimal view, haemodynamic parameters, Patient reactivity score(PRS) and complications were noted. Unpaired t-test, chi-square test were used. A total of 73 patients were included for study with 38 in group DL and 35 in group VL. The grade of laryngeal view was found to be significantly better with Airtraq® VL compared to Macintosh laryngoscope without the application of BURP (p < 0.05). In the DL group, 34.2% (n = 13) had a CL grade I, 36.8% (n = 14) had CL grade 2A, 13.2% had CL grade 2B (n = 5) and 15.8% (n = 6) had CL Grade 3 at the end of thyroidectomy. On the contrary, in the VL Group, 71.5% (n = 25) of the participants had a CL Grade I; whereas, 20% (n = 7) had a CL Grade 2A, 5.7% (n = 2) had CL grade 2B and 2.8% (n = 1) of participants had CL grade 3. The mean "time taken to achieve optimal view' was comparable between the two groups (DL = 39.16 ± 105.53 s vs. VL = 38.89 ± 20.69 s) (p = 0.988).The haemodynamic parameters, Patient reactivity score and complications were comparable between the two groups. The performance of Airtraq® videolaryngoscope, a channelled VL is better than conventional Macintosh laryngoscope in terms of the optimal glottic view obtained to rule out recurrent laryngeal nerve palsy at the end of thyroidectomy.