Elevated blood lactate levels may indicate poor prognosis in liver failure

A new study on fulminant hepatic failure (FHF), a sudden and severe shutdown of the liver, examined ways of determining early on whether patients would benefit from a transplant as opposed to responding to other medical treatment. The results showed that elevated blood lactate levels indicate a poor prognosis and thus the need for a transplant.

The results of this study appear in the September 2005 issue of Liver Transplantation, the official journal of the American Association for the Study of Liver Diseases (AASLD) and the International Liver Transplantation Society (ILTS). The journal is published on behalf of the societies by John Wiley & Sons, Inc. and is available online via Wiley InterScience.

Although it is rare, FHF is the reason that up to 7 percent of liver transplants are performed. However, because life-threatening complications can quickly develop with the disorder, coupled with the fact that some patients recover without having to undergo a transplant, time is of the essence in determining whether or not to perform the surgery. Various criteria have been used to establish a prognosis, the most widely applied of which is the King's College Hospital criteria, which can be helpful in indicating the need for a transplant, but do not predict patients who will not survive without one.

Led by Gerry C. MacQuillin, of the Department of Gastroenterology and Hepatology of the Sir Charles Gairdner Hospital in Nedlands, Australia, while working in Birmingham UK, researchers examined two markers that could play a role in predicting FHF outcomes: serum phosphate and serum blood lactate levels. The study included 83 patients with FHF admitted to the Liver Unit at Queen Elizabeth Hospital in Birmingham, England between August 2000 and March 2003. Patients were divided into those who survived with medical treatment, those who underwent a liver transplant, and those who died. Patients were also grouped according to whether or not they had overdosed on paracetamol (Tylenol), a common cause of FHF. Of the 83 patients, 58 percent survived with medical treatment, 23 percent underwent liver transplants, and 19 percent died. Those who had overdosed on paracetamol had a much higher recovery rate: 73 percent survived with medical treatment, compared to 26 percent of those who had not overdosed.

The results showed that serum phosphate levels were significantly higher in those who died or underwent a transplant, but there was not a significant difference when comparing those who died to those who were treated without having a transplant. Lactate levels were significantly higher during the 12 hour period following admission to the hospital in those who died or underwent a transplant, and this difference was also seen between those who died and those who survived without a transplant, whether or not they had overdosed.

The authors surmise that high blood lactate levels were an accurate predictor of a poor outcome in FHF patients. "Our data has showed that serial blood lactate measurements were higher in nonsurvivors, with increasing significance in relation to time," they state. "This raises the importance of close monitoring of serial arterial blood lactate levels." The authors conclude by proposing that curves of blood lactate levels, which would need to be examined in further studies, be established to predict FHF outcomes.

Also in the September 2005 issue of Liver Transplantation, an accompanying editorial by A. Obaid Shakil of the Division of Gastroenterology, Hepatology and Nutrition at the University of Pittsburgh School of Medicine notes that in determining the need for a transplant, the window for decision-making in FHF is short compared to other liver diseases, and the criteria currently used are inadequate. "The current study provides further evidence of the prognostic value of serum lactate during the early phase of fulminant hepatic failure," he states. "If validated by well-powered prospective studies, blood lactate level may serve as an additional criteria to the well-tested King's College Hospital criteria." He cautions, however, that clinicians should not rely solely on these tests, but should use them in combination with all other available information.