EFFECTS OF TOTAL HEPATECTOMY ON HEMODYNAMIC STATE AND ORGAN UPTAKE OFCATECHOLAMINES IN THE PIG

In a previous study, we showed that plasma concentrations of catechola mines were increased during the anhepatic phase in pigs. In this study , we investigated if a constant depth of anaesthesia would prevent the se changes and, if not, if the changes were caused by impaired extract ion of catecholamines. We measured arterial and venous pressures, hear t rate and cardiac output in 10 anaesthetized pigs. Hepatic arterial a nd portal venous flows were measured. Blood for measurement of catecho lamines was sampled from carotid and pulmonary arteries and portal, he patic and renal veins. After a 2-h observation period, the liver was r emoved and the circulation reconstituted. Measurements were made and s amples obtained for another 2 h. Catecholamine concentrations increase d 2-10-fold after hepatectomy. Before hepatectomy, noradrenaline was e xtracted by the lung (mean extraction ratio 23 (SEM 8) %) and the live r (30 (11) %); after hepatectomy, there was extraction by the kidney ( 24 (12) %) but extraction by the lung (29 (8) %) was unchanged. Before hepatectomy, adrenaline was extracted predominantly by the kidney (73 (5) %) and the liver (70 (6) %), with minimal extraction by the lung; after hepatectomy, extraction by the lung increased (25 (4) %) and de creased slightly in the kidney (56 (6) %). While mean arterial pressur e did not change, heart rate increased by approximately 50% and cardia c index declined (ns) within 2 h after hepatectomy. There was a sharp increase in pulmonary vascular resistance after removal of the liver a nd changes correlated with increases in arterial plasma concentrations of catecholamines.