The purpose of this study was to assess the effect of inflating a laryngeal mask airway ProSeal(TM) (PLMA(TM)) cuff, prior to insertion, on the degree of difficulty of inserting a PLMA(TM) by the inexperienced, and the incidence of postoperative sore throat.

Before induction, we measured the thyromental and sternomental distance. PLMA(TM) insertions were conducted by those with experience of less than 15 previous insertions. One hundred and five consecutive patients undergoing general anesthesia were randomized into 3 groups: In group 1, the PLMA(TM) was inserted with the cuff fully deflated, in group 2, the cuff was partially inflated (i.e., filled with half the recommended air), in group 3, the cuff was fully inflated. Successful insertion was judged primarily by the clinical function of the airway. The number of insertion attempts to achieve a satisfactory airway were recorded. Each patient was asked whether he had a sore throat, dysphonia, or dysphagia just before leaving the postanesthesia care unit (PACU) and again 24 hr after surgery.

The number of insertion attempts required to achieve a satisfactory airway and the failure rate of insertion were not significantly different in the 3 groups. However, the 3 groups were significantly different in terms of the incidence of postoperative sore throat in the PACU. This was highest in group 3 (P<0.05). The incidences of other variables of laryngopharygeal morbidity in the PACU and 24 hrs after surgery were not significantly different in the 3 groups.

Inflation of the cuff prior to insertion did not affect the success rate of inserting a PLMA(TM) by the inexperienced, and PLMA(TM) insertion after partial inflation was associated with higher incidence of postoperative sore throat in the PACU. Thus, in general anesthesia, it is desirable that the inexperienced insert the PLMA(TM) with the cuff fully deflated.