An Inquiry on Airway Management by McCoy Blade with Elevated Tip and Miller Straight Blade with Paraglossal Technique: Relevance for Difficult Airway Management in Current Infectious Times

Background: Modifications of curved and straight laryngoscope blades have been used for airway management since a long time. While McCoy blade with an elevated tip is commonly used to intubate patients with anticipated difficult airway, the Miller's straight blade is used for intubations in children and less commonly adults. In this study, we revisit the paraglossal technique of Miller's straight blade as a method to improve laryngeal view especially in difficult intubations. Aim: This study aimed to compare laryngoscopic view and ease of intubation (EOI) using McCoy blade elevated tip and Miller's straight blade paraglossal technique. Materials and Methods: A prospective single-blind study was conducted on 170 patients undergoing elective surgery under general anesthesia. They were randomly allotted to two groups. In Group A, laryngoscopy was performed by Miller's blade paraglossal approach, whereas in Group B, laryngoscopy was performed by McCoy blade with an elevated tip. Laryngeal view was graded using the modified Cormack–Lehane grading, and EOI was graded using EOI score. These were compared with preoperative intubation prediction score. Statistical analysis was done using "Medcalc" version 19.0.3. Numerical and categorical data were analyzed by Student's t-test and Chi-square test, respectively. A P < 0.05 was considered statistically significant. Results: The paraglossal approach with Miller's blade offered better laryngoscopic view as compared with McCoy blade with an elevated tip in normal (54.1% vs. 25.9%) and difficult airway (44.7% vs. 11.8%). Tracheal intubation was easier with McCoy blade with an elevated tip although the success rate of intubation improved with the assistance of a bougie with Miller's straight blade paraglossal approach. Conclusion: The laryngeal view was significantly better with the paraglossal approach of Miller's straight blade even in difficult airway. McCoy blade with an elevated tip was also found to be a useful tool to have in difficult airway, as EOI is significantly higher. The study also highlights the usefulness of adjuncts such as a gum elastic bougie while intubating.