The observation of circulation and oxygen metabolism during anhepatic phase of classic orthotopic liver transplantation without bypass

Objective: To observe the changes of circulation and oxygen delivery/consumption during anhepatic phase of classic orthotopic liver transplantation (OLT) without bypass and estimate the anesthetic process. Methods: Twenty patients undergoing OLT without bypass under combined general anesthesia were enrolled in this observation. Left radial artery was cannulated and Swan-Ganz catheter was placed in the pulmonary artery via right internal jugular vein to monitor circulation continuously and core blood temperature. Mean artery blood pressure(MAP), heart rate(HR), central venous pressure(CVP) and cardiac output(CO) were recorded at several time points such as 5 min before interruption of inferior vena cava (T0), 5 min(T1),20 min(T2) after interruption and 5 min before unclamping of inferior vena cava(T3). At the same time blood samples were taken from radial and pulmonary artery for blood gas analysis to record oxygen partial pressure(PaO2,PvO2) and saturation of blood oxygen(SaO2,SvO2) and calculate cardiac index(CI),stroke volume index(SVI), system vascular resistance(SVR); oxygen delivery (DO2I)and oxygen consumption(VO2I) were also calculated at these time points. Results: CI, SVI, MAP and DO2I were decreased significantly (P0.01) at T1 compared with T0, SVR was increased (P0.05) and VO2I, ERO2 were increased too (P0.01) at the same time point. With the process of anhepatic phase there was the decreasing trend in CO and CI. At T2 compared with T1 DO2I and VO2I were decreased (P0.01). Conclusion: During the anhepatic phase of classic OLT without bypass the balance of oxygen delivery and oxygen consumption is as important as the change of hemodynamics. For the safety of patients the imbalance should be avoided.