Fiberoptic assessment of laryngeal mask airway placement: blind insertion versus direct visual epiglottoscopy

The study aims to compare the frequency of ideal anatomic placement of the laryngeal mask airway (LMA) using the traditional blind insertion approach with one where placement was facilitated by the use of a laryngoscope (epiglottoscopy).

A prospective comparison of 132 patients divided into 2 groups (38 with the blind technique and 94 with the direct technique) were evaluated with 2 airway assessment methods, Wilson and Mallampati. We also considered whether there was a relationship between these criteria and the successful placement into an ideal position. Other variables were considered, including breathing airflow dynamics, body size, and skill level of the anesthesia care provider. Five placement visual ordinals were used to grade the LMA position.

All of the patients studied except one had good to excellent breathing patterns after LMA placement. Statistically more patients who had ideal to nearly ideal placement position of the LMA were placed under direct epiglottoscopy than when placed by the classic blind technique. The position of the LMA was assessed by fiberoptic examination through an attachment between the LMA and the anesthetic circuit. Eighty-six of 94 patients (91.5%) in the direct visual placement group had ideal position compared with 16 of 38 (42%) in the blind placement group. Both groups had more successful placement than any other studies by comparison. Even several obese patients were successfully treated by either technique, and even the inexperienced anesthesia care provider could place the LMA with considerable accuracy.

One hundred thirty-one of 132 patients had no airway difficulties after LMA placement with either blind (classic) or direct visual epiglottoscopy (laryngoscopy). A fiberoptic scope proved to be a valuable tool to assess the results. When ideal placement is either highly desirable or necessary, the direct visual technique is considered to be a better choice for placement than the blind, classic method.