Comparative evaluation of two techniques of LMA CTrach^TM insertion on manoeuvres required to obtain optimal laryngeal view

Background: LMA CTrach™ is a laryngeal mask airway (LMA™) device used for tracheal intubation under vision. We conducted this study to evaluate the new technique of LMA CTrach™ insertion with respect to number of manoeuvres of airway required to obtain grade 1 or 2 view of glottis when compared to standard recommended insertion technique. Methods: One hundred and ten patients were randomized to either group standard technique (LMA CTrach™ inserted according to manufacturer's recommendations) or group modified technique (LMA CTrach™ inserted with the viewer assembled and visualizing the process of insertion). The number of manoeuvres used before successful intubation were compared between the groups. Manoeuvres used to get adequate ventilation/good glottic view were the up-down manoeuvre, partial withdrawal, distal maneuver, Chandy manoeuvre and suctioning. Total number of manoeuvres and ease of LMA CTrach™ insertion were recorded. Results: Patient characteristics were comparable. Among 50 patients in each group 37 patients required 43 manipulations in group modified technique compared to 41 patients who required 65 manipulations in group standard technique before getting a good glottic view (P=0.013). Modified insertion technique was significantly difficult (23/50 patients) compared to standard technique (6/50 patients); P<0.001. Conclusion: The total number of manoeuvres for getting good glottic view was significantly less with the modified technique of inserting LMA CTrach™. However, this technique was perceived to be more difficult.