保护性肺通气联合PCV—VG对单肺通气老年患者的肺保护效应

Lung-protective effect of lung-protective ventilation combined with pressure-controlled ventilation-volume guaranteed in elderly patients undergoing one-lung ventilation

目的评价保护性肺通气联合压力控制容量保证模式（PCV-VG）对单肺通气老年患者的肺保护效应。方法择期行全腔镜食管癌根治术患者80例，年龄65～80岁，体重指数15～28 kg/m2，ASA分级Ⅰ-Ⅲ级。采用随机数字表法分为4组（n＝20）：常规对照组（C组）、PCV-VG组、保护性肺通气组（LPV组）和保护性肺通气联合PCV-VG组（LPV＋PCV-VG组）。于双肺通气改变手术体位后20 min（T1）、单肺通气30 min（T2）、恢复双肺通气20 min（T3）时采集桡动脉血样行血气分析，并测定气道峰压（Ppeak）、气道平均压（Pmean）、肺动态顺应性（Cdyn）。T2时计算肺泡-动脉氧分压差、肺内分流率（Qs/Qt）、死腔率（Vd/VT）和呼吸指数。于麻醉诱导前及术毕采集桡动脉血样，采用ELISA法测定血浆中性粒细胞弹性蛋白酶（NE）浓度。术后1和7 d行临床肺部感染评分（CPIS），记录术后7 d内呼吸衰竭、肺不张和肺部感染等肺部并发症的发生情况。结果与C组比较，PCV-VG组Ppeak降低，Pmean升高，LPV组Ppeak和PaCO2升高，pH值、Vd/VT和Qs/Qt降低，LPV＋PCV-VG组Ppeak、Vd/VT、Qs/Qt、pH值和术后CPIS评分降低，Pmean、Cdyn和PaO2升高，PCV-VG组、LPV组和LPV＋PCV-VG组术毕NE浓度降低（P 〈0.05）；与PCV-VG组比较，LPV＋PCV-VG组Pmean、Cdyn和PaO2升高，pH值、Qs/Qt、术毕NE浓度和CPIS评分降低（P 〈0.05）；与LPV组比较，LPV＋PCV-VG组Ppeak、Qs/Qt、术毕NE浓度和CPIS降低，Cdyn升高（P 〈0.05）。4组术后均未见呼吸衰竭、肺不张和肺部感染等肺部并发症发生。结论保护性肺通气联合PCV-VG可优化单肺通气老年患者的肺保护效应。

ObjectiveTo evaluate the lung-protective effect of lung-protective ventilation（LPV）combined with ventilatory mode pressure-controlled ventilation-volume guaranteed（PCV-VG）in elderly patients undergoing one-lung ventilation（OLV）.MethodsEighty American Society of Anesthesiologists physical statusⅠ-Ⅲ patients, aged 65-80 yr, with body mass index of 15-28 kg/m2, scheduled for elective radical resection for esophageal cancer performed via video-assisted thoracoscope, were divided into 4 groups（n=20 each）using a random number table： control group（group C）, PCV-VG group, LPV group and LPV combined with PCV-VG group（group LPV＋ PCV-VG）. At 20 min after changing the body position during two-lung ventilation（T1）, 30 min of OLV（T2）and 20 min after restoration of two-lung ventilation（T3）, blood samples were collected from the radial artery for blood gas analysis and for determination of peak airway pressure（Ppeak）, mean airway pressure（Pmean）and dynamic lung compliance（Cdyn）. Alveolar-arterial oxygen gradient, intrapulmonary shunt（Qs/Qt）, dead space fraction（Vd/VT）and respiratory index were calculated at T2.Blood samples were collected from the radial artery before induction of anesthesia and at the end of operation for determination of plasma neutrophil elastase（NE）concentrations by enzyme-linked immunosorbent assay.The Clinical Pulmonary Infection Score（CPIS）was assessed at 1 and 7 days after operation, and the development of pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection was recorded within 7 days after operation.ResultsCompared with group C, Ppeak was significantly decreased, and Pmean was increased in group PCV-VG, Ppeak and PaCO2 were significantly increased and pH value, Vd/VT and Qs/Qt were decreased in group LPV, Ppeak, Vd/VT, Qs/Qt, pH value and postoperative CPIS were significantly decreased, and Pmean, Cdyn and PaO2 were increased in group LPV＋ PCV-VG, and the NE concentration at the end of operation was significantly decreased in PCV-VG, LPV and LPV＋ PCV-VG groups（P〈0.05）. Compared with group PCV-VG, Pmean, Cdyn and PaO2 were significantly increased, and pH value, Qs/Qt, NE concentration at the end of operation and CPIS were decreased in group LPV＋ PCV-VG（P〈0.05）. Compared with group LPV, Ppeak, Qs/Qt, NE concentration at the end of operation and CPIS were significantly decreased, and Cdyn was increased in group LPV＋ PCV-VG（P〈0.05）. Pulmonary complications such as respiratory failure, pulmonary atelectasis and pulmonary infection were not observed after operation in the four groups.ConclusionLPV combined with PCV-VG can optimize the lung-protective effect in elderly patients undergoing OLV.