The Changes Of Oxygen Delivery/consumption, Blood Glucose And Lactic Acid During Anhepatic Phase Of Standard Orthotopic Liver Transplantation Without Bypass

Objective:To observe the changes of hemodynamics,blood oxygen transport. blood glucose and lactate during anhepatic phase of standard orthotopic liver transplantation(OLT)without bypass.To find out the tendency of oxygen metabolism change and guide the anesthetic process.Methods:23 patients undergoing OLT without bypass under combined general anesthesia were enrolled in this observation.Left radial artery was cannulated and 6-cav.Swan-Ganz catheter was placed in the pulmonary artery via right internal jugular vein to monitor central venous pressure(CVP),mean pulmonary arterial pressure(MPAP),core blood temperature(BT)and cardiac output(CO)with thermodilution method.Mean arterial pressure(MAP),heart rate(HR),CVP,MPAP and 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 and biochemistry analysis to record arterial oxygen partial pressure(PaO₂),mixed venous oxygen partial pressure (PvO₂),arterial oxygen saturation(SaO₂),mixed venous oxygen saturation(SvO₂), BT and hemoglobin concentration(Hb).Arterial blood glucose(Glu),lactic acid(Lac) and hydrogen ion concentration(pH)were recorded in 20 patients.Cardiac index(CI), stroke volume index(SVI),systemic vascular resistance(SVR),arterial oxygen content(CaO₂),venous oxygen content(CvO₂),oxygen delivery/oxygen delivery index(DO₂/DO₂I),oxygen consumption/oxygen consumption index(VO₂/VO₂I)and oxygen extraction rate(ERO₂)were calculated at these time points.Results:(1)circulation changes:MAP decreased about 11%after interruption inferior vena cava(P＜0.05),and then came back to the level before interruption.HR increased about 25%(P＜0.01)and stayed high during anhepatic phase.CVP and MPAP were decreased obviously(nearly 69%and 47%.P＜0.01)and kept the low level.CO/CI decreased nearly 20%(P＜0.01)and were continued degression(T₂,T₁: P＜0.01;T₃,T₂:P＜0.05).SVI decreased 36%(P＜0.01)and was continued degression (T₂,T₁.P＜0.01).SVR increased about 17%(P＜0.05)and was continued increase (T₂,T₁:P＜0.01).(2)oxygen metabolism changes:PaO₂,PvO₂,SvO₂ and CvO₂ were decreased obviously(P＜0.01),CvO₂ showed the increase trend during anhepatic phase.DO₂/DO₂I decreased about 18%(P＜0.01)at T₁ compared with T₀,and then continued decrease(T₂,T₁:P＜0.01).VO₂/VO₂I abruptly increased about 24% (P＜0.01),and then were obviously decreased and under the level of pre-anhepatic phase(T₂,T₀,T₃,T₀:P＜0.01).ERO₂ increased about 46%(P＜0.01)at the initiation of the anhepatic phase,and then changed quietly.(3)Glu,Lac and pH changes:Lac and pH continued increase during the observation period.Glu showed the increase trend at first(T₂,T₀:P＜0.01),and then decreased(T₃,T₂:P＜0.01)Conclusion:(1)Circulation fluctuated severely during anhepatic phase of standard OLT.Oxygen delivery and oxygen consumption changed obviously and showed the decrease at equal pace.Though the reasons were different the balance between oxygen delivery and consumption was retained.(2)Arterial lactic acid increased during anhepatic phase,it was in nubibus whether lactate reflected the change of oxygen metabolism.More precise quantitative analysis was needed.(3) Arterial blood glucose continued the increasing trend after the operation and reached the peak 20 min after interruption inferior vena cava,and then there was the decreasing trend but higher than normal.