The Changes Of Extravascular Lung Water During The Perioperative Period Of Orthotopic Liver Transplantation

ObjectiveTo investigate the changes of extravascular Lung Water during the perioperative period of orthotopic liver transplantation .Materials and Methods24 consecutive patients with end-stage liver disease undergoing Orthotopic Liver transplantation (OLT) were studied. Before induction of anesthesia, peripheral venous and radial arterial line were inserted, and in all patients ECG and pulsoximetry were monitored. After anesthesia induction, a pulmonary artery catheter was inserted via a 7.5 French introducer into the right internal jugular vein for continuous cardiac output (CCO) measurement and to monitor central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), mean pulmonary artery pressure (MPAP), pulmonary vascular resistance index (PVRI), systematic vascular resistance index (SVRI). In all patients a 5 French fiberoptic catheter with a thermistor was placed in the brachial artery and connected to the PiCCO system. Extravascular lung water (EVLW), intrathoracic blood volume (ITBV), and pulse continuous cardiac output (PCCO) were monitored. After induction of anesthesia and achievement of stable hemodynamic and respiratory conditions, recordings of the baseline values of hemodynamic data, ITBV and EVLW were determined. The patients were studied during the anhepatic stage and 1 hour, 2 hours after reperfusion of the graft. Final measurements of all the values were determined immediately after operation. All data were sampled and analyzed by a statistician using SPSS (version 11.5) statistical program. Mean values and standard deviations were calculated (mean±SD). Arepeated analysis of variance was used to assess differences between baseline and the different time points of measurement. The significance of differences between two time points of measurements was analyzed by a paired t test. A Pearson correlation was performed to assess associations between CCO and PCCO, ELWI and other hemodynamic values. A P-value of <0.05 was considered as significant.ResultsPatients experienced an approximately 50% decrease in CCO during the anhepatic stage in accordance with a significant decrease in MAP, CVP, MPAP, PAOP and an increase in HR compared to baseline values. PVRI and SVRI increased significantly during this period. Reperfusion led to an increased CCO above baseline, increased central filling pressures (CVP, PAOP, MPAP), and significantly decreased vascular resistance indices. During the following time points of measurement, a tendency towards normalization or in direction towards baseline values was observed. CCO and filling pressures remained increased, whereas systemic vascular resistance remained decreased, thus, none of them reached baseline values. Baseline values of ITBV (1152.40±323.70 ml/m2) increased compared to normal values (800-1000ml/m2) and indicated adequate hydration. During the anhepatic stage, ITBV tended to decrease significantly (820.15±235.77ml/m2), whereas reperfusion led to a statistically significant increase—compared to anhepatic values—in ITBV (1392.79±401.22,1177.13±241.14, 1298.75±398.43ml/m2), which remained statistically unchanged to baseline values during the rest of the study period. EVLW remained statistically unchanged during the whole study period in all patients though all of them increased compared to normal values (3-7ml/kg). EVLW correlated with ITBV significantly (r=0.822, P<0.05).ConclusionThe changes of EVLW during perioperative period of orthotopic livertransplantation were very little by the instruction of a protocol of anensthesia in liver transplantation, which is made in Beijing Friendship Hospital. ITBV seems to be a more reliable predictor of cardiac preload, but CVP and PAOP should not be neglected. Circulative volume overload is perhaps the most important cause of the increase of EVLW, so that proper perioperative fluid management is one of the most important aspects governing hemodynamic function in the patients of liver transplantation.