Hypothermia for fulminant hepatic failure: A cool approach to a burning problem

Background: Increased intracranial pressure as a complication of acute live r failure has a mortality of about 90% in patients who do not respond to tr eatment with mannitol and ultrafiltration. We investigated the safety and e fficacy of moderate hypothermia for uncontrolled increase in intracranial p ressure in patients with acute liver failure. Methods: We studied seven con secutive patients aged 16-48 years (five women, four candidates for orthoto pic liver transplantation [OLT]) with acute liver failure who fulfilled cri teria for poor prognosis liver failure and had increased intracranial press ure that was unresponsive to two treatments with mannitol and ultrafiltrati on. We used cooling blankets to lower the patients' core temperature to 32- 33 degrees C. Patients who were not suitable candidates for OLT (patients 1 -3) were cooled for 8 h and then gradually rewarmed over 1 h to a baseline temperature of 37 degrees C. Patients who were suitable candidates for OLT (patients 4-7) were cooled before and during the OLT procedure. We measured cerebral blood flow and metabolic indices before and after cooling. Findin gs: The four patients who were candidates for OLT were successfully maintai ned until transplantation with 13 h (range 10-14 h) of hypothermia. The thr ee patients who were unsuitable candidates for OLT died after rewarming. In tracranial pressure before cooling was 45 (25-49 mm Hg) and was reduced in all patients to 16 (13-17) mm Hg (p < 0.05). Cerebral blood flow decreased from 103 (25-134) mi 100 g(-1) min(-1) before cooling to 44 (24-75) mi 100 g(-1) min(-1) after cooling (p < 0.05). The corresponding changes for cereb ral perfusion pressure was an increase from 45 mm Hg (37-56) mm Hg to 70 (6 0-78) mm Hg (p < 0.05) and for cardiac index a decrease from 3.8 (7-13) to 5.1 (4.3-6.1) L per min per m(2) of body surface area. During hypothermia t here was no significant relapse of increased intracranial pressure. Arteria l ammonia and cerebral uptake of ammonia were significantly reduced with co oling. No adverse effects of hypothermia were observed. Interpretation: Mod erate hypothermia is useful in the treatment of uncontrolled increase in in tracranial pressure in patients with acute liver failure and may serve as a bridge to OLT.