Laryngoscopic versus intubating LMA guided tracheal intubation by novice users--a manikin study

Airway control is a potentially lifesaving procedure but tracheal intubation by direct laryngoscopy is difficult. This pilot study was conducted to determine whether tracheal intubation was more rapid and the success rate higher using an intubating laryngeal mask airway.

The success rates of 119 medical students without prior airway management experience in ventilating and then intubating the trachea of a Laerdal Airway Management Trainer with two different methods were compared. The methods were bag-mask ventilation (BM-V) followed by laryngoscopic intubation (LG-TI), and intubating laryngeal mask ventilation (ILMA-V) followed by ILMA-guided tracheal intubation (ILMA-TI). After an introductory lecture and demonstration, each student was allowed three attempts to intubate using each method in random order.

All participants were successful with BM-V and ILMA-V on the first attempt. Laryngoscopic tracheal intubation was achieved by 60 (50.4%), 31 (26.1%) and 12 (10.1%) participants on the first, second and third attempt, respectively, while 16 (13.4%) failed in all three attempts. In the ILMA-TI group, 107 (90.0%), 10 (8.4%) and 2 (1.6%) succeeded on the first, second and third attempt, respectively. None failed. The intergroup difference is highly significant (p<0.001). Male participants were more successful with LG-TI than female (p<0.01), but not with ILMA-TI.

Laryngoscopic orotracheal intubation is difficult for the untrained, but all participants were successful with ILMA-TI. These data suggest that alternative devices such as the ILMA should be included in the medical school curriculum for airway management.