Different Techniques for Insertion of the ProSeal Laryngeal Mask Airway in Patients With Difficult Airway

The ProSeal laryngeal mask airway (PLMA) is a new laryngeal mask device with a modified cuff to improve the seal and a drain tube to prevent aspiration and gastric insufflation. The manufacturer recommends inserting the PLMA using digital manipulation, like the Classic LMA, or with an introducer tool (IT), like the Intubating LMA. The mean (range) frequency of insertion success at the first attempt for these techniques is 84% (81-100) and 95% (90-100) respectively, with the main causes of insertion difficulty being impaction at the back of the mouth and failure of the distal cuff to reach the hypopharynx. Howarth et al described an insertion technique which overcomes these difficulties by using a gum elastic bougie (GEB) placed in the esophagus to guide the PLMA around the back of the mouth and into its correct position in the hypopharynx. Howarth et al reported no failed uses from 100 consecutive insertions. In the following study, we test the hypothesis that GEB-guided insertion is more frequently successful than the digital and IT techniques in patients with difficult airway.