Airway management using LMA-evaluation of three insertional techniques-a prospective randomised study

Laryngeal Mask Airway [LMA] insertion has become as a basic procedural skill needed for all health care providers. Search for the most successful insertion technique continues. We evaluated the success rate of the three LMA insertion techniques- standard, 90 degree rotational and 180 degree rotational technique.

A total of 180 patients of ASA I-II aged 18-65 years undergoing open superficial surgical procedures with (LMA® Unique™ Airway, Teleflex®, Teleflex Medical Europe Ltd, Ireland) as an airway management device and with neuromuscular blocking agents, were randomly allocated to three groups, in this prospective randomized study. In the standard technique group (n = 60), the LMA was inserted by standard digital intraoral method. In the 90 degree rotational technique group (n = 60), the LMA was rotated counter-clockwise through 90 degree in the mouth and advanced until the resistance of the hypopharynx was felt, and then straightened out in the hypopharynx. In 180 degree rotational technique, LMA was inserted back-to-front, like a Guedel airway. The parameters studied were: the LMA placement success at first attempt, insertion time, need for more than one attempt at insertion, need for external airway manipulations, postoperative sore throat, blood staining and other post-operative (airway related) complications.

The first attempt success rate in the standard technique was 83.9%, in 90 degree rotational technique was 75% and 180 degree rotational was 93.5%. The first attempt success rate was higher in 180 degree rotational group compared to 90 degree rotational group (P < 0.05), but there was no statistically significant difference (P > 0.05) between 90 degree rotational group and the standard technique group. There was no statistically significant difference among the two groups in terms of the secondary outcomes.

We conclude that 180 degree rotational technique of LMA insertion is more successful than 90 degree rotational technique in adult patients under general anaesthesia.