保护性肺通气模式在结核性毁损肺全肺切除术麻醉中的价值

The Value of Protective Lung Ventilation during Anesthesia for Tuberculous Destructuve Pneumonectomy

目的探讨小潮气量通气和呼气末正压通气(positive end expiratory pressure,PEEP)结合压力控制通气(pressure controlled ventilation,PCV)对结核性毁损肺(tuberculous destroyed lung,TDL)患者全肺切除术单肺通气(one-lung ventilation,OLV)呼吸力学、肺内分流(Qs/Qt)、Pa02和术后肺部感染等的影响。方法经首都医科大学附属北京胸科医院医学伦理委员会批准,选取2016年8月至2018年3月在首都医科大学附属北京胸科医院接受择期开胸全肺切除手术的TDL患者为研究对象,共48例。采用随机数字表法将患者分为观察组和对照组,每组24例。观察组OLV期间潮气量6ml/kg,OLV开始即刻给予PCV通气,然后给予7cm H20(1cm H20=0.0098 kPa)的PEEP通气;对照组OLV期间潮气量8ml/kg。记录OLV前(T1)、OLV开始后30min(T2)及全肺切除术后5min(T3)时气道峰压(Ppeak)和平台压(Pplat);T1、T2、T3和术后6h(T4)抽取动静脉血,测血气指标pH、PaCO2和PaO2,并计算Qs/Qt值;术后第1天、第7天行临床肺部感染评分。计量资料组间比较,若方差齐,采用f检验,若方差不齐采用t’检验;组内比较采用重复测量设计的方差分析;计数资料比较采用Xz检验,均以P<0.05为差异有统计学意义。结果T2时与对照组比较,观察组Ppeak明显降低[观察组:(21.0±2.2)cm H2O;对照组:(22.4±2.2)cm H2O;t=-2.446,P=0.021];T2时与对照组比较,观察组Pplat明显降低[观察组:(19.7±2.2)cm H2O;对照组:(21.0±2.7)cm H20;t=-3.610,P=0.001];T3时与对照组比较,观察组pH明显降低[观察组:7.3±0.053;对照组,7.37±0.047;-3.000,P=0.006];T2时与对照组比较,观察组PaCO2明显升高[观察组:(44.0±2.2)mm Hg(1mm Hg=0.133kPa);对照组:(35.7±4.0)mmHg;t=7.091,P=0.000];T2时与对照组比较,观察组Qs/Qt明显降低[观察组:(21.4±5.4)%;对照组:(25.4±6.8)%;t=-0.256,P=0.020];T4时与对照组比较,观察组PaO2/FiO2明显升高[观察组:(181.2±29.0)mm Hg;对照组:(159.1±25.2)mm Hg;t=2.938,P=0.009]。术后第1天,与对照组比较,观察组肺部感染评分明显降低[观察组:(4.7±0.6)分;对照组:(5.2±0.9)分;t=-2.567,P=0.017]。结论小潮气量和PEEP结合PCV的通气模式,在TDL患者开胸全肺切除手术OLV中可以较好地降低OLV期间气道压力、降低Qs/Qt,改善术后Pa02,降低术后第1天肺部感染的评分。

Objective To discuss the impact of respiratory mechanics,intrapulmonary shunt(Qs/Qt),Pa02 and postoperative pulmonary infection during one-lung ventilation(OLV)using small tidal volume and positive end-expiratory pressure(PEEP)with pressure controlled ventilation(PCV)in total pneumonectomy with tuberculous destroyed lung(TDL).Methods The present study was approved by the medical ethics committee of Beijing Chest Hospital affiliated to Capital Medical University.The study enrolled 48 TDL patients receiving selective thoracotomic total pneumonectomy from August 2016 to March 2018.A random number table was used to divide the patients into observation group and control group,24 cases in each group.The tidal volume of the observation group was 6 ml/kg during OLV,and PCV was administered immediately from the beginning of OLV followed by PEEP at 7 cm H20(1cm H20=0.0098kPa).The tidal volume of the control group was 8ml/kg during OLV.Airway peak pressure(Ppeak)and plateau pressure(Pplat)before OLV(T,),30 min after OLV(T2)and 5 min after total pneumonectomy(T3)were recorded.Arterial and venous blood samples were collected at T,,T2,T3 and at 6 h after surgery(T4),the blood gas indicators pH,PaC02 and Pa02 were measured,and Qs/Qt ratio was calculated.Clinical pulmonary infection was scored at day 1 and day 7 after surgery.Measurements were compared between the two groups;paired t-test was used for the comparison if there was homogeneity of variance;otherwise,t-test was used.Repeated-measures analysis of variance was performed for intragroup comparisons.Counting data were analyzed by χ^2 test,P<0.05 was statistically significant.Results Compared with the control group,Ppeaj^observation group:(21.0±2.2)cm H20;control group:(22.4±2.2)cm H20;t=-2.446,P=0.021)and Pplat(observation group:(19.7±2.2)cm H20;control group:(21.0±2.7)cm H20;t=-3.610,P=0.001)in the observation group decreased significantly at T2 and the pH value of the observation group at T3 decreased significantly(observation group:7.34±0.053;control group:7.37±0.047;t=-3.000,P=0.006).At T2,PaC02 of the observation group was significantly higher than that of the control group(observation group:(44.0±2.2)mm Hg(1mm Hg=0.133 kPa);control group:(35.7±4.0)mm Hg;t=7.091,P=0.000),while Qs/Qt ratio decreased significantly(observation group:(21.4±5.4)%;control group:(25.4±6.8)%;t=-0.256,P=0.020).Compared with the control group at T4,the Pa02/Fi02 ratio of the observation group increased significantly(observation group:(181.2±29.0)mm Hg;control group:(159.1±25.2)mm Hg;f=2.938,P=0.009).At the first day post operation,the pulmonary infection scores of the observation group decreased significantly compared with that of the control group(observation group:4.7±0.6;control group:5.2±0.9;r=-2.567,P=0.017).Conclusion Small tidal volume and PEEP with PCV could effectively reduce airway pressure and Qs/Qt ratio during OLV for thoracotomic total pneumonectomy,and improve Pa02 and pulmonary infection scores of TDL patients at the first day postoperative.