Comparison of noxious stimulations induced by insertion of Proseal laryngeal mask airway and classic laryngeal mask airway in children

Objective To compare the noxious stimulations induced by insertion of Proseai laryngeal mask airway(PLMA)and classic laryngeal mask airway(CLMA)in children.Methods Forty-seven ASA Ⅰ or Ⅱ children,aged 3-12 yr and undergoing surgery under general anesthesia,were randomly divided into 2 groups:PLMA group(group P,n =23)and CLMA group(group C,n =24).General anesthesia was induced with target-controlled infusion(TCI)of propofol.When the effect-site concentration of propofol was equal to the plasma concentration predetermined.PLMA or CLMA insertion was attempted.The target plasma concentration of propofol was predetermined according to Dixon's up-down method,with 0.2 μg/ml as a step size.The initial target plasma concentration of propofol was 6 μg/ml and 4.4 μg/ml for groups P and C,respectively.The preedetermined target plasma concentration of propofol and the satisfaction of insertion conditions for each child were recorded.Results The 50％ effective concentration(EC50)of propofol to achieve satisfied condition of PLMA and CLMA insertion were 5.87(95％ CI,5.62-6.11)and 4.53(95％ C1,4.38-4.69)μg/nl,respectively,and the difference was significant(P ＜ 0.01).Conclusion The noxious stimulation induced by insertion of PLMA in children aged 3-12 years is stronger than that of CLMA. Key words: laryngeal masks; Dose-response relationship, drug; Child