The intubating LMA: A comparison of insertion techniques with conventional tracheal tubes

Purpose: To compare the performance of the intubating laryngeal mask airway (ILMA) in assisting blind tracheal intubation with conventional tracheal tubes of different curvatures and the frequency of possible associated complications. Methods: After informed consent, 240 ASA I-II adults undergoing elective surgery participated in a randomized, single blind clinical trial to receive blind trachea intubation via ILMA with a conventional tracheal tube curved with normal (Normal group) or reversed (Reverse group) direction. More than three attempts at intubation was regarded as failure. The lowest oxygen saturation during intubation was recorded and postintubation sore throat and hoarseness were evaluated with verbal analog scales. Results: The overall success rates of intubation with Normal and Reverse groups were not different (96.7% and 94.2% respectively). Successful intubation at the first attempt was higher in the Reverse group than in the Normal group (86.7% vs 75.0%, P=0.033). The incidence of sore throat was higher in the Normal group than in the Reverse group (19.2% vs 9.2% respectively, P =0.042). Conclusions: Blind trachea intubation via an ILMA with the conventional curved tracheal tube is feasible and highly successful. Reverse curve direction is preferable at the first attempt of intubation for its higher success rate and lower incidence of complications.