Effectiveness of Two Training Methods for Avoiding Excessive Inflation of Laryngeal Mask Airway Supreme

To evaluate the effectiveness of two training methods for avoiding excessive inflation of laryngeal mask airway(LMA)Supreme.

Totally 41 anesthesiologists were randomly divided into hand touch group(H group,n=20)and short-term pressure gauge training group(G group,n=21). Before training,subjects were asked to inflate the cuff of LMA Supreme to two target pressures,30 cmH(2)O and 60 cmH(2)O, according to their own experiences. The actual cuff pressures were recorded as baseline pressures. Subjects in H group then received the training of hand touch:touch the vermilion of the lip and apex nasi with the left ring finger and feel the hardness. A cuff pressure with hardness similar to the vermilion of the lip was defined as 30 cmH(2)O, and similar to the apex nasi as 60 cmH(2)O. Subjects in G group were asked to inflate the cuff with a pressure gauge and feel the hardness of the cuff when the pressure reached 30 cmH(2)O and 60 cmH(2)O. After one-week training,two groups of subjects repeated the cuff inflation test. Actual cuff pressures after training were also recorded and compared with the baseline pressures. Results Actual cuff pressures after training[Group H:(39.7±15.7) cmH(2)O(P=0.00);Group G:(26.2±13.2) cmH(2)O(P=0.03)]were significantly lower than baseline pressures in both groups when the target cuff pressure was 30 cmH(2)O, and the differences were not statistically significant between these two groups(P=0.06). When the target pressure was 60 cmH(2)O,the actual cuff pressure of H group [(91.1±24.3)cmH(2)O] was significantly higher than that of G group [(58.1±15.4) cmH(2)O (P=0.01)]. However,the actual cuff pressure of G group was similar to the target pressure.

The two training methods are equally effective when the target pressure is 30 cmH(2)O, while short-term pressure gauge training method is superior when the target pressure is 60 cmH(2)O.