Evaluation of ease of intubation using C-MAC Vs Macintosh laryngoscope in patients with the application of manual inline axial stabilization - A randomized comparative study

Background and Aims: Endotracheal intubation in patients with cervical spine injury can be challenging particularly in the presence of manual in line stabilization. Video laryngoscopes can be used in these situations as their popularity is growing in the management of difficult airway and recently Difficult Airway Society (DAS) has included these devices in their algorithm.

Methods: Sixty ASA 1 and 2 patients with normal airway requiring general anesthesia with endotracheal intubation were recruited for this randomized comparative simulative study. Neck was stabilized using manual inline axial stabilization maneuver and endotracheal intubation was carried out using either C-MAC or Macintosh laryngoscope. The following parameters were compared: intubation difficulty score (IDS), Cormack Lehane (CL) glottis view, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). Hemodynamic parameters were noted at following intervals: pre-induction, pre intubation, immediate post intubation and 3 minutes after intubation. The data was analyzed using statistical tests Fischer exact test, Chi-square and independent two tailed student t test

Results: Superior glottis view was observed in C-MAC group (CL-1: 56.7 % vs 30%, CL-2: 36.7% vs 56.7%, CL-3: 6.7% vs 10%, CL-4: none vs 3.3% in C-MAC and Macintosh group respectively). There was no difference in intubation difficulty score (p=0.822) and hemodynamic parameters also showed no clinical and statistical differences.

Conclusion: The present study shows good glottis view with C-MAC; although, IDS score is similar to conventional Macintosh laryngoscopy. The haemodynamic parameters are comparable in both groups. Overall, the C-MAC laryngoscope gives better glottis view indicating clinical significance.