CEREBRAL PERFUSION DURING HUMAN LIVER-TRANSPLANTATION

During transplantation of the liver cerebral perfusion was monitored by transcranial Doppler determined middle cerebral artery mean flow velocity (V-mean) and pulsatility index (PI) in six fulminant hepatic failure patients and 11 patients with chronic liver disease. In both groups of patients V-mean, PI and central haemodynamic variables were recorded during (1) the last preanhepatic hour, (2) the anhepatic phase; (3) the first 15 min of reperfusion; and (4) for the following 45 min of reperfusion. No significant differences were detected between the two groups of patients with respect to changes of variables with time. The V-mean (40+/-13 cm s(-1) [mean+/-SD]), thoracic electrical impedance (TI) (30+/-7 Ohm), heart rate (97+/-19 beats min(-1)), mean arterial pressure (84+/-9 mmHg) and arterial carbon dioxide tension (Pa-CO2, 4.5+/-0.4 kPa) remained stable in the anhepatic phase, while cardiac output (CO, 7.6+/-2.7 to 5.4+/-1.41 min(-1)), stroke volume (SV, 79+/-26 to 56+/-15 ml) and PI (1.2+/-0.3 to 0.9+/-0.2) decreased (P<0.05). During reperfusion, CO (9.9+/-4.01 min(-1)), SV (105+/-40 ml), Pa-CO2 (5.5+/-0.6 kPa), V-mean (57+/-17 cm s(-1)) and PI (1.2+/-0.2) became elevated. Taken together, during the anhepatic phase of the liver transplantation a maintained central blood volume as indicated by the constant TI served for a stable blood pressure and in turn cerebral perfusion, whereas revascularization of the graft increased cerebral perfusion concomitant with an elevated carbon dioxide tension.