Learning to exchange an endotracheal tube for a laryngeal mask prior to emergence

Purpose: To present a stepwise training method, first critiquing laryngeal mask (LM) insertion difficulty and malpositioning, then learning how to exc hange an endotracheal tube (ETT) for a LM during emergence from anesthesia. Methods: "Learning phase:" sixty adults were enrolled in a preliminary stud y in which ETT/LM exchange was not performed - only LM insertion difficulty and malpositioning in the presence of an oral ETT were evaluated. After in duction of anesthesia and oral intubation, a classic LM size 4 was inserted using the standard recommended technique. Number of insertion attempts and fibreoptically determined malpositions were recorded. "ETT/LM exchange pha se:" we performed airway exchange in 50 patients selected from our individu al practices. Results: "Learning phase:" the LM was satisfactorily positioned, on first a ttempt, in 95% of cases. With multiple insertion attempts it was possible t o place the LM in all 60 intubated patients. Unsuccessful initial placement of the LM was always due to insufficient insertion depth (5%), When fully inserted into the hypopharynx, the epiglottis could be viewed fibreopticall y in 13% of cases. "ETT/LM exchange phase:" the LM was inserted successfull y in all 50 patients on first attempt. No complications occurred during any exchange. Conclusion: We found it is easy to learn how to insert a LM in the presence of an oral ETT The most serious malposition, occurring in 5% of first atte mpts, was insufficient insertion depth. The only other malposition we encou ntered, fibreoptic visualization of the epiglottis, is not likely to result in complete airway obstruction following endotracheal extubation under ane sthesia.