Whole body gas exchange: amino acid and lactate clearance as indicators of initial and early allograft viability in liver transplantation.

A method for the rapid assessment of liver allograft circulation and function after liver transplantation is described. In 12 patients undergoing liver transplantation continuous recording of whole body energy production was made on the basis of gas exchange measurements during the surgical procedure. Oxygen consumption decreased rapidly by 25% when the blood supply to the native liver was interrupted. After the anhepatic period, there was a sharp increase of oxygen consumption with successful reperfusion of the allograft. Carbon dioxide production fell by 14% and returned to preanhepatic values after successful declamping. In two cases with suboptimal reperfusion the return of gas exchange values was slow and incomplete. Results from the studies of whole body energy production were compared with biochemical measurements. No significant accumulation of amino acids occurred during the anhepatic period, but in the two patients with incomplete revascularization, clearance of amino acids, after the anhepatic phase, was impaired and plasma amino acids accumulated. The same pattern was found for plasma lactate levels. By the techniques described in this article, rapid and reliable assessment of initial and early graft function in hepatic transplantation is possible. This is of great value for the intraoperative and early postoperative assessment and planning of surgical and anesthesiologic strategies.