Anticipated Difficult Tracheal Intubation: Comparison between conventional laryngoscope (Macintosh) and video laryngoscope TrueView EVO2

Abstract

Context: In patients with anticipated difficult airway, it is difficult to align the oropharyngolaryngeal axis to facilitate intubation by conventional laryngoscopy, which leads to failed intubation. The TruView EVO 2 laryngoscope is a device with a unique blade that provides an optical view around the corner. The blade is a modified laryngoscope blade incorporating an unmagnified optic side port with anterior fraction of 42΀ in the line of sight allowing indirect tracheal intubation. Aim: The aim of the study was to compare TrueView blade with Macintosh blade with respect to the (view of the glottis by (Cormack-Lehane grading); Time for tracheal Intubation, Attempts required for intubation, maneuvers to optimize the laryngeal view and success rate of intubation); Settings and Design: It was a prospective, randomized controlled single blind clinical study. Materials and Methods: Seventy ASA grade I and II, Mallampatti Grading (MPG), III and IV patients posted for elective surgery with restricted neck mobility such as post-burn contracture neck, cervical spine surgeries divided into Group 1-35 patients (Trueview) and Group 2-35 patients (Macintosh). All intubation was done by an expert anesthesiologist. Statistical Analysis: Tests used were Mann-Whitney U test, two independent sample t-tests, Chi-square test, and Fischer's exact t-test. Results: Cormack-Lehane Grade I was seen in 62.85% and O in Group 1 and Group 2, respectively. Grade II was seen in 37.14% and 28.57% in Group 1 and Group 2, respectively, and Grade III in 0 and 71.42% in Groups 1 and 2, respectively, which was statistically significant. Thus EVO 2 improved the view of glottis by 2 Grades. Both the techniques were comparable as far as time is concerned. A 94.2% patients in Group 1 intubated in 1 st attempt, 5% needed 2 nd attempt, whereas in Group 2 72.7% patients were intubated in 1 st attempt and 27.2% in 2 nd attempt. Maneuver BURP required more with conventional laryngoscopy. Success rate in Group 1 was 100% and in Group 2 it was 94.2%. Conclusion: The use of TrueView in patients with anticipated difficult airway considerably improved the view of glottis. With adequate experience, the number of attempts may be reduced and maneuver required for securing airway successfully could be optimized.