Cerebral blood flow and oxygenation in liver transplantation for acute or chronic hepatic disease without venovenous bypass

The autoregulation of cerebral blood flow (CBF) is impaired in patients with end-stage liver disease and encephalopathy, These patients are vulnerable to sudden deterioration of cerebral perfusion and oxygenation during liver transplantation. We compared CBF and metabolism during liver transplantation without venovenous bypass and 24 hours postoperatively in 9 patients with acute liver failure (ALF) and 16 patients with chronic liver disease. A fiberoptic catheter was inserted cranially through the left internal jugular vein for determination of jugular venous oxygen saturation, cerebral oxygen extraction ratio (COER), lactate level, and neuron-specific enolase (NSE) level. Arterial concentrations of lactate were also measured. Flow velocity in the middle cerebral arteries was monitored bilaterally using transcranial Doppler sonography. Mean flow velocity and pulsatility index (PI) were regarded as indicators of intracranial pressure. Core body temperatures were recorded. Mild hyperventilation, perioperative hemofiltration, and N-acetylcysteine infusion were used according to our clinical practice. NSE level was greater in acute patients at: the end of surgery (P <.05), but not 24 hours later. Lactate concentrations were greater in patients with ALF (P <.001) preoperatively and intraoperatively but were similar in both groups 24 hours postoperatively. There was no difference between arterial and jugular venous concentrations of lactate. Changes in blood flow velocity, PI, and GOER were parallel and without statistical significance between the groups. The patients' core temperature did not correlate with CBF, NSE level, or clinical outcome. Caval clamping was well tolerated in both patient groups.