呼气末正压对非停跳冠脉搭桥移植术患者麻醉中和术后肺血分流的影响

Effect of PEEP on Intrapulmonary Shunting during Anesthesia and after Operation in the Patients Undergoing OPCABG Surgery

目的研究呼气终末正压(PEEP)通气对非停跳冠状动脉搭桥移植术(OPCABG)患者麻醉中和术后肺血分流(Q.s/Q.t)的影响。方法20例OPCABG患者,随机分为实验组和对照组,各10例。全麻诱导下,实验组给予PEEP机械通气,分别在麻醉诱导后、开胸后即刻、冠脉吻合中、关胸后即刻、术后24h取动脉血和右房血行血气分析,并计算肺血分流量。结果与基础值相比,实验组在术中Q.s/Q.t逐渐减少(P<0.05),术后24h恢复至近正常范围;术中及术后两组不同时点Q.s/Q.t比较,差异有统计学意义(P<0.05)。结论对于OPCABG患者全麻后应用PEEP机械通气,可有效防治麻醉与手术相关发生下垂肺区域的肺不张,减少术中和术后肺血分流。

Objective To study the effect of positive end-expiratory pressure （PEEP） on intrapulmonary shunting during anesthesia and after operation in the patients undergoing off- pump coronary artery bypass grafting （OPCABG） surgery. Methods Twenty patients undergoing OPCABG surgery were randomly divided into PEEP group （group P） and the control group （group C） with 10 cases each. Induced by general anesthesia, the patients in group P were mechanically ventilated with PEEP 5 cm H20. Blood gas analysis was peiformed and Qs/Qt was calculated right after anesthesia induction, right after opening thorax, during coronary artery bypass grafting, right after closing thorax and 24 hours after the operation,respectively. Results Qs/Qt in group P was decreased gradually during the operation as compared to the baseline values （T1） and recovered to almost normal level 24 hours after the operation. But in group C, Qs/Qt increased continually during the operation and was still higher 24 hours after the surgery. There was statistically significant difference in Qs/Qt between the two groups at four time points （P 〈 0.05）. Conclusion The application of PEEP in OPCABG surgery decreases Qs/Qt and prevents postoperative hypoxemia and pulmonary atelectasis, which is advantageous for patients in pulmonary fimction recovery.