呼气末正压对保护性通气下泌尿外科后腹腔镜手术患者术中肺功能的影响

Effect of positive end-expiratory pressure on intraoperative pulmonary function in patients undergoing urological retroperitoneal laparoscopic surgery in mode of protective ventilation

目的 评价呼气末正压（PEEP）对保护性通气下泌尿外科后腹腔镜手术患者术中肺功能的影响.方法 择期行后腹腔镜输尿管切开取石术患者40例,性别不限,年龄30 ～ 64岁,体重指数16～ 29 kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法分为2组（n=20）：对照组（C组）和PEEP组（P组）.麻醉诱导气管插管后至气腹开始前行间歇正压通气,设定潮气量8 ml/kg,通气频率12次/min,吸呼比1：2,吸入氧浓度50％;气腹开始后C组设定潮气量6 ml/kg,通气频率22次/min,吸呼比1.0：1.5,维持PETCO235～45 nmHg;P组设定潮气量6 ml/kg,通气频率22次/min,吸呼比1.0：1.5,PEEP 5 cmH2O,维持PETCO2 35～45 mmHg.分别于气腹前5 min （T1）、气腹10 min（T2）、气腹30 min（T3）、气腹60 min（T4）、气腹结束即刻（T5）和拔除气管导管前5 min（T6）时,采集桡动脉血样行血气分析,并记录气道峰压和平均气道压,计算动态肺顺应性、氧合指数、呼吸指数、死腔率和肺泡-动脉血氧分压差.结果 与C组比较,P组T2-4时平均气道压升高,T3时氧合指数升高,T3和T6时肺泡-动脉血氧分压差和呼吸指数降低（P＜0.05）,各时点气道峰压、动态肺顺应性和死腔率差异无统计学意义（P＞0.05）.结论 呼气末正压（5 cmH2O）可改善保护性通气下泌尿外科后腹腔镜手术患者术中肺功能.

Objective To evaluate the effect of positive end-expiratory pressure （PEEP） on intraoperative pulmonary function in the patients undergoing urological retroperitoneal laparoscopic surgery in the mode of protective ventilation.Methods Forty patients of both sexes,aged 30-64 yr,with body mass index of 16-29 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective retroperitoneal laparoscopic ureterolithotorny,were randomly divided into 2 groups （n =20 each） using a random number table：control group （group C） and PEEP group （group P）.After induction of general anesthesia,the patients were endotracheally intubated.Intermittent positive pressure ventilation （tidal volume [Vr] 6 ml/kg,respiratory rate [RR] 12 breaths/min,inspiratory/expiratory ratio [I：E] 1：2,fraction of inspired oxygen 50%） was performed from the end of intubation until the onset of pneumoperitoneum.After the onset of pneumoperitoneum,the patients were ventilated （VT 6 ml/kg,RR 22 breaths/min,I：E 1.0：1.5）,and the end-tidal pressure of carbon dioxide was maintained at 35-45 mmHg in group C.After the onset of pneumoperitoneum,the patients were ventilated （VT 6 ml/kg,RR 22 breaths/min,I：E1.0：1.5,PEEP 5 cmH2O）,and the end-tidal pressure of carbon dioxide was maintained at 35-45 mmHg in group P.At 5 min before pneumoperitoneum （T1）,at 10,30 and 60 min of pneumoperitoneum （T2-4）,immediately after the end of pneumoperitoneum （T5）,and at 5 min before extubation （T6）,arterial blood samples were collected for blood gas analysis.Peak airway pressure and mean airway pressure were also recorded.Dynamic lung compliance,oxygenation index,respiratory index,dead space fraction and alveolararterial oxygen gradient were calculated.Results Compared with group C,mean airway pressure was significantly higher at T2-4,oxygenation index was significantly higher at T3,alveolar-arterial oxygen gradient difference was significantly lower at T3 and T6,and respiratory index was significantly lower at T6 （P〈0.05）,and no significant change was found in the peak airway pressure,dynamic lung compliance and dead space fraction at each time point in group P （P〉0.05）.Conclusion PEEP （5 cmH2O） can improve the intraoperative pulmonary function in the patients undergoing urological retroperitoneal laparoscopic surgery in the mode of protective ventilation.