驱动压导向呼气末正压个体化滴定对老年患者腹腔镜结直肠癌根治术后肺不张的影响

Effects of individualized driving pressure-guided positive end-expiratory pressure titration on postoperative atelectasis in elderly patients undergoing laparoscopic radical resection of colorectal cancer

目的探讨基于肺超声评分(LUS)评估驱动压导向呼气末正压(PEEP)个体化滴定对老年患者腹腔镜结直肠癌根治术后肺不张的影响。方法选择2021年11月至2022年5月择期行腹腔镜结直肠癌根治术患者60例,男39例,女21例,年龄≥65岁,BMI<30 kg/m^(2),ASAⅡ或Ⅲ级。采用随机数字表法将患者分为三组:驱动压A组(A组)、驱动压B组(B组)和对照组(C组),每组20例。A组和B组在完成气管插管后通过滴定PEEP寻找驱动压最低值,与驱动压最低值相应的PEEP值为最优PEEP值。A组术中进行动态PEEP优化,每隔1 h或进行与肺塌陷有关的操作后均重复PEEP滴定;B组选择最优PEEP完成机械通气;C组以5 cm H_(2)O的固定PEEP完成机械通气。记录麻醉诱导前(T_(0))、手术结束气管导管拔除前(T_(5))和气管导管拔除后30 min(T_(6))的LUS和肺不张发生情况。记录平卧位最优PEEP设置完成后5 min(T_(1))、气腹后30 min(T_(2))、气腹后1 h(T_(3))、关闭气腹后10 min(T_(4))的气道峰压(Ppeak)、气道平台压(Pplat)、PEEP、P_(ET) CO_(2)和血气分析结果,并计算驱动压、肺静态顺应性(Cstat)、氧合指数(OI)、死腔/潮气量比值(V_(D)/V_(T))。记录术后7 d肺部并发症的发生情况。结果与T_(0)时比较,T_(5)、T_(6)时三组LUS明显升高(P<0.05)。与T_(1)时比较,T_(2)、T_(3)时三组Ppeak、Pplat、驱动压和PaCO_(2)明显升高,Cstat明显降低(P<0.05)。与A组比较,B组T_(2)、T_(3)时驱动压明显升高,T_(2)-T_(4)时PaO_(2)、Cstat、OI明显降低;C组T_(2)-T_(4)时驱动压明显升高、Cstat明显降低,T_(1)-T_(4)时PaO_(2)、OI明显降低;T_(5)、T_(6)时B组和C组LUS和肺不张发生率明显升高(P<0.05)。与B组比较,C组T_(2)-T_(4)时驱动压明显升高,T_(1)时PaO_(2)、OI明显降低(P<0.05)。三组术后肺部并发症总发生率差异无统计学意义。结论驱动压导向PEEP个体化滴定能够降低老年患者腹腔镜结直肠癌根治术后LUS和肺不张发生率,并改善呼吸系统力学和氧合功能。

Objective To investigate the effects of individualized driving pressure-guided positive end-expiratory pressure(PEEP)titration based on lung ultrasound score(LUS)on postoperative atelectasis in elderly patients undergoing laparoscopic radical resection of colorectal cancer.Methods Sixty patients scheduled for elective laparoscopic radical resection of colorectal cancer under general anesthesia from November 2021 to May 2022,39 males and 21 females,aged≥65 years,BMI<30 kg/m^(2),ASA physical statusⅡorⅢ,were randomly divided into three groups:driving pressure group A(group A),driving pressure group B(group B),and control group(group C),20 patients in each group.In groups A and B,the PEEP titration was decremented to the lowest driving pressure after endotracheal intubation.The PEEP which produced the lowest driving pressure was the optimal PEEP.The above PEEP titration was repeated every 1 hour and when performing predefined events that may be associated with lung collapse in group A,while the optimal PEEP was used throughout the mechanical ventilation in group B.Mechanical ventilation was performed with fixed PEEP 5 cmH_(2)O in group C.The LUS and incidence of atelectasis were recorded before surgery(T_(0)),at the end of surgery but before extubation(T_(5)),and 30 minutes after extubation(T_(6)),respectively.The airway peak pressure(Ppeak),airway plateau pressure(Pplat),PEEP,P_(ET) CO_(2),and blood gas analysis were collected for analysis 5 minutes after optimal PEEP setting in supine position(T_(1)),30 minutes after pneumoperitoneum establishment(T_(2)),1 hour after pneumoperitoneum establishment(T_(3)),and 10 minutes after pneumoperitoneum cessation(T_(4)),respectively.The driving pressure,static lung compliance(Cstat),oxygenation index(OI),and dead chamber/tidal volume ratio(V_(D)/V_(T))were also caculated at T_(1)-T_(4).The occurrence of postoperative pulmonary complications(PPCs)was followed up within 7 days postoperatively.Results Compared with T_(0),LUS were significantly increased in the three groups at T_(5) and T_(6)(P<0.05).Compared with T_(1),Ppeak,Pplat,driving pressure,and PaCO_(2)were significantly increased,while Cstat were significantly decreased in the three groups at T_(2) and T_(3)(P<0.05).Compared with group A,the driving pressure were significantly increased at T_(2) and T_(3),PaO_(2),Cstat,and OI were significantly decreased at T_(2)-T_(4) in group B,the driving pressure were significantly increased,and Cstat were significantly decreased at T_(2)-T_(4),PaO_(2)and OI were significantly decreased at T_(1)-T_(4) in group C,LUS and incidence of atelectasis were significantly increased at T_(5) and T_(6) in groups B and C(P<0.05).Compared with group B,the driving pressurewere significantly increased at T_(2)-T_(4),PaO_(2)and OI were significantly decreased at T_(1) in group C(P<0.05).There were no significant differences in the incidence of PPCs among the three groups.Conclusion Application of individualized driving pressure-guided PEEP titration can reduce the lung ultrasound score and postoperative atelectasis,improved respiratory mechanics and oxygenation in elderly patients undergoing laparoscopic radical resection of colorectal cancer.