非转流肝移植手术中血管外肺水、肺血管通透性及死腔/潮气容积比的变化

目的:探讨非体外静脉转流下原位肝移植手术中血管外肺水(EVLW)、肺血管通透性和死腔/潮气容积比(VD/VT)的变化及原因。方法:对15例晚期肝病行原位肝移植手术的患者行全身麻醉,术中全凭静脉靶控输注麻醉药维持,气管插管后经右颈内静脉和右股动脉放置PiCCO导管,通过PiCCO监护仪测定EVLW和肺血管通透性指数(PVPI),左桡动脉穿刺行动脉压监测和血气分析。分别记录手术开始30min(T1)、无肝期前15min(T2)、无肝期15min(T3)、无肝期45min(T4)、新肝期15min(T5)、新肝期60min(T6)、关腹(T7)时的EVLW、PVPI和动脉血气分析结果与呼气末二氧化碳浓度。结果:T4的EVLW明显低于T5,T3、T4的PVPI明显高于T5、T6和T7,T3、T4的VD/VT明显高于其他5个时刻。结论:非转流肝移植手术无肝期应当控制补液和EVLW,新肝期血管开放后可适当应用降低EVLW的药物,避免新肝期血管开放后引起肺水肿,无肝期的肺增血管通透性明显增高,有隐性肺损伤的可能,要注意采取适当的肺保护措施,无肝期的VD/VT高于其他两期,应当适当地减少通气量,以保持肺通气和血流的匹配。

Changes of extravascular lung water,pulmonary vascular permeability,and the dead space/tidal volume ratio during non-bypass orthotopic liver transplantation

Objective To investigate the changes of extravascular lung water(EVLW), pulmonary vascular permeability and the dead space/tidal volume ratio(VD/VT) during orthotopic liver transplantation (OLT) without anhepatic veno-venous bypass. Methods Fifteen patients with end-stage liver disease underwent general anesthesia and target-controlled infusion of anesthetics for OLT. After tracheal intubation, EVLW and pulmonary vascular permeability index(PVPI) were monitored using the PiCCO system connecting with the catheters inserted via right internal jugular vein and femoral artery, and arterial pressure and blood gas (ABG) were detected. EVLW, PVPI, ABG, and end-tidal carbon dioxide were recorded 30 min after surgery (T1), 15 min at the preanhepatic phase (T2), 15 min (T3) and 45 min (T4) at the anhepatic phase, 15 min (T5) and 60 min (T6) at the neohepatic phase, and at laparorrhaphy (T7). Results EVWL was markedly lower at T4 than at T5, whereas PVPI were dramatically higher at T3 and T4 than at T5, T6, and T7, VD/VT was significantly higher at T3 and T4 than at the other time points. Conclusion For patients undergoing OLT without veno-venous bypass, solution infusion and EVWL should be limited in the anhepatic phase. EVLW-lowering agents can be properly used to prevent pulmonary edema due to unclamping the blood vessels in the neohepatic phase. Appropriate measures should be taken to protect the lungs from injury secondary to the markedly increased capillary permeability in the anhepatic phase. The ventilatory volume should be reduced to maintain the balance between alveolar ventilation and blood flow because the VD/VT ratio was higher in the anhepatic phase than in the other two phases.