微创医学

目的观察压力容积曲线(pressure-volume curve,P-V环)指导呼气末正压(positive end-expiratory pressure,PEEP)小潮气量通气对CO2气腹截石位手术患者脑血流的影响。方法将全麻下行CO2气腹截石位择期手术患者50例(TNM分期Ⅰ~Ⅲ期直肠癌根治术11例、子宫肌瘤全宫切除术39例)(ASAⅠ~Ⅱ级),随机分为2组,对照组(A组)和P-V环组(B组),每组25例。气腹前,两组通气参数设定:潮气量(VT)为8 ml/kg,呼吸频率(RR)12次/min,吸呼比1∶2。气腹后A组通气参数不变;B组通气参数:PEEP值(PLIP+VT)为6 ml/kg,RR 18次/min。于气腹前(T0)、气腹后30 min(T1)、60 min(T2)测呼气末CO2分压(P ET CO2)、气道峰压(Ppeak)、平均气道压(Pmean);测定心率和平均动脉压;颈内静脉球部和桡动脉采血行血气分析,检测动脉血氧分压(PaO2)、动脉二氧化碳分压(PaCO2)、动脉血氧饱和度(SaO2)、颈内静脉血氧分压(PjvO2)、颈内静脉血氧饱和度(SjvO2)、颈内静脉血氧含量(CjvO2),根据Fick公式计算动脉-颈内静脉血氧含量差(Ca-jvDO2)。结果组内比较:与T0相比,两组T1、T2时MAP、HR、Pmean、Ppeak、P ET CO2、PaCO2、PjvO2、SjvO2、CjvO2明显升高(P<0.05),而两组T1、T2时PaO2、Ca-jvDO2均显著减小(P<0.05)。组间比较:与A组相比,B组T1、T2时Pmean、P ET CO2、PaCO2、SjvO2均明显增高(P<0.05),而Ppeak均显著减小(P<0.05),B组T1时Ca-jvDO2显著减小(P<0.05)。结论 P-V环指导下PEEP值、小潮气量通气可以改善CO2气腹截石位手术患者的脑血流量和脑氧供需平衡。

Objective To observe the effects of positive end-expiratory pressure ventilation guided by pressure-volume curve on cerebral blood flow of patients undergoing gynecological laparoscopic surgery in lithotomy position． Methods Fifty patients ( ASA I ～ II) scheduled to undergo gynecological laparoscopic surgery under general anesthesia were randomly divided into two groups( using random number table，n = 25) : control group ( Group A) and P-V curve group ( Group B) ． Before pneumoperitoneum，the tidal volume ( VT) of all patients was set as 8 ml /kg，respiratory rate ( ＲＲ) 12 times /min，and respiratory ratio 1: 2． After pneumoperitoneum，patients in Group A maintained the previous parameters，while patients in group B were adjusted as follow: PEEP ( PLIP + VT ) of 6ml /kg，ＲＲ of 18 times /min． End-tidal partial pressure of CO2 ( PETCO2 ) ，peak airway pressure the ( Ppeak) ， and mean airway pressure ( Pmean) were measured，heart rate ( HＲ) and mean arterial pressure( MAP) were monitored and recorded; samples of right radial artery and right internal jugular vein were obtained to measure arterial oxygen pressure ( PaO2 ) ， arterial carbon dioxide partial pressure ( PaCO2 ) ， internal jugular venous blood oxygen partial pressure ( PjvO2 ) ，internal jugular venous oxygen saturation ( SjvO2 ) ， and jugular vein oxygen content ( CjvO2 ) ， and the arterial-internal jugular venous blood gas oxygen content ( Ca-jvDO2 ) was calculated according to Fick＇s formula before pneumoperitoneum ( T0 ) ， 30 min( T1) and 60 min( T2 ) after pneumoperitoneum．Ｒesults In paired comparisons，compared with T0，the MAP，HＲ，Pmean，Ppeak，PET CO2 ，PaCO2 ，PjvO2 ，SjvO2 ，and CjvO2 of two groups at T1and T2 were significantly increased ( P ＜ 0． 05) ，while PaO2 and Ca-jvDO2 were significantly reduced ( P ＜ 0． 05) ． PETCO2 ， Pmean，PaCO2 ，and SjvO2 of group B at T1 and T2 were significantly higher than those of group A ( P ＜ 0． 05 ) ，while Ppeak significantly reduced ( P ＜ 0． 05 ) ，and so did Ca-jvDO2 of group B at T1 ． Conclusions Positive end-expiratory pressure ventilation with low tidal volume guided by pressure-volume curve can improve the cerebral blood flow，balance of cerebral oxygen supply，and demand of patients undergoing gynecological laparoscopic surgery in lithotomy position．