肺复张策略对成人瓣膜置换术后肺换气功能的影响

Effect of Recruitment Maneuver for Lung Ventilation Function in Adult Patients Undergoing Cardiac Valve Replacement

【目的】研究肺复张策略（RM）改善成人体外循环（CPB）心脏换瓣术后肺换气功能的作用。【方法】选择30例心阿直视换瓣手术患者，随机分成常规机械通气组（A组）、早期肺复张组（B组）、晚期肺复张组（C组）。B组在劈开胸骨后实施肺复张策略，C组在到达重症监护室（ICU）后循环稳定后实施肺复张策略。分别于术前（T1）、CPB后（T2）、到达ICU后1h（T3）、2h（T4）、12h（T5）5个时间点记录各项呼吸指标并测动脉和混合静脉血血气，并根据公式计算肺换气功能指标。【结果】B、C组在T2、T3、T4和T5时，氧合指数（OI）高于A组（P〈0．05），而肺泡-动脉血氧分压差（PA-aO2）和肺内分流量（Os／Qt）低于A组，C组各肺换气功能指标在T4时间内与B组无统计学意义（P〉0．05），而T5时OI高于B组（P〈0．05），PA-aO2、Qs／Qt低于B组（P〈0．05）。【结论】肺复张策略能减轻CPB后肺损伤，且晚期肺复张策略优于早期肺复张策略。

[Objective]To evaluate the effect of lung recruitment maneuvers（RM） to improve the function of lung＇ ventilation in adult patients undergoing cardiac valve replacement in.cardiopulmonary bypass （CPB）. [Methods] Thirty patients undergoing cardiac valve replacement were randomly divided into conventional mechanical ventilation group（Group A）, early recruitment maneuver group（Group B） and late recruitment maneuvers group（Group C）. Group B started RM directly after median sternotomy. Group C started RM when the circulation was stable after arrival in intensive care unit（ICU）. Respiration indices were measured. Arterial and mixture venous blood was taken for gas analysis at before operation（T1 ）, after CPB（T2）, 1 h （T3）, 2 h （T4） and 12 h（T5） after arrival in ICU. Lung ventilation indices were calculated. [Results] Oxygenation index （OI） of Group B and C was higher than that of Group A（ P d0. 05）, but PA-aO2 and intrapulmonary shunt volume（Qs/Qt） were lower（ P 〈0.05） at the time point of T2 ,T3 ,T4 and T5. Lung ventilation indices had no significant difference between Group C and Group B before T4 （ P 〉0.05）. OI of Group C was higher than that of Group B at T5, but PA-aO2 and Qs/Qt were lower. [Conclusion]RM can attenuate lung injury af ter CPB. Late application of RM has a better effect as compared with early application.