Effects of cortisol administration on hepatic circulation during brain death in rabbits

Hemodynamic instability and endocrinologic alterations during brain death contribute to dysfunction of donor organs. The present study was conducted to examine the effect of cortisol administration on hepatic circulation in brain-dead hypotensive donors.

Brain death was created by inflating a balloon catheter inserted into the epidural space in rabbits. In another set of experiments, non-brain-dead rabbits were bilaterally adrenalectomized. At 1 hour of equilibration after brain death or adrenalectomy, cortisol at a dose of either 0.05 or 5 mg/kg/hr was given intravenously for 5 hours.

The induction of brain death resulted in a significant decrease in mean arterial pressure (MAP), whereas MAP after adrenalectomy was maintained. Both brain death and adrenalectomy caused an approximately 40% decrease in the portal vein blood flow (PVF) and hepatic tissue blood flow (HTF) and a significant increase in serum hyaluronic acid (HA) level as well as alanine aminotransferase (ALT) level. These changes were associated with a substantial decrease in serum cortisol level. Transmission electron microscopic examination showed swollen Kupffer cells with phagocytosis. Cortisol supplement after brain death or adrenalectomy significantly increased PVF and HTF to prevalues without affecting MAP. Both dosing rates of cortisol also significantly decreased serum HA and ALT levels and attenuated Kupffer cell activation.

These results suggest that cortisol administration exhibits beneficial effects on hepatic circulation in hemodynamically unstable brain-dead animals.