小儿食管引流型喉罩与经典喉罩插入时适宜呼气末七氟醚浓度的比较

A comparison of optimal concentrations of sevoflurane for insertion of the proseal laryngeal mask airway or classic laryngeal mask airway in children

目的比较小儿食管引流型喉罩（PI．MA）与经典喉罩（CLMA）插入所需的七氟醚最低肺泡有效浓度（MAC）。方法择期全麻手术患儿54例，年龄3～9岁，ASAⅠ或Ⅱ级，随机均分为PLMA组（P组）和CLMA组（C组）。患儿吸入七氟醚行麻醉诱导，待呼气末七氟醚浓度（CerSev）达到预设值并稳定10min后插入喉罩。七氟醚的预设值根据Dixon序贯法确定，P、C组首例患儿初始CrrSev分别设为2．2％和2．0～40，浓度梯度为0．2％。结果患儿插入PLMA和CLMA所需的七氟醚MAC分别为（2．21±0．11）%和（1．99±0．11）％（P〈0．01），P、C组CET、Sev的EC95分别为2．40％（95％CI2．28％42．74％）和2．14％（95％CI2．03％～2．44％）。结论3～9岁小儿PLMA插入条件满意所需的七氟醚MAC较插入CLMA高。

Objective To quantify and compare the minimum alveolar concentration （MAC） of sevoflurane for insertion of the proseal laryngeal mask airway （PLMA） and classic laryngeal mask airway （CLMA） in children. Methods Fifty four ASA I or ]] children, aged 3 to 9 years old, undergoing surgery under general anesthesia, wererandomly divided into 2 groups： the PLMA group （group P） and CLMA group （group C）, with twenty seven cases in each group. General anesthesia was induced via mask with sevoflurane, and the PLMA or CLMA was inserted after a predetermined end-tidal sevoflurane concentration was maintained for at least I0 min. The end-tidal sevofIurane concentration was predetermined according to Dixon＇s up-down method, with 0. 2% as a step size. The initial patients received 2.2% and 2.0% sevoflurane for group P and group C, respectively. The insertion conditions were noted as dissatisfactory when the jaw was not relaxed enough to allow for PLMA or CLMA insertion, or coughing, swallowing, movement of the limbs, breath holding, laryngospasm occurred within 1 min of insertion of PLMA or CLMA. The predetermined sevoflurane concentration and the satisfaction of insertion conditions for each child were recorded. Results The MAC of sevoflurane to achieve satisfying condition of the PLMA and CLMA insertion in 50% of children were （2.21 ± 0. 11） % and （ 1.99 ± 0. 11） %, respectively, and the difference was significant （P〈0. 01）. The ED95 （95%CI） were 2.40% （2.28%-2.74%） and 2.14% （2.03%-2.44%） for the satisfying condition of the PLMA and CLMA insertion, respectively. Conclusion The MAC of sevoflurane to achieve satisfying insertion condition of the PLMA in 50% of children aged 3 to 9 yrs was higher than that of CLMA. [K