Acute liver failure (ALF), is a life-threatening deterioration of liver function in people without preexisting cirrhosis. It can be caused by acetaminophen toxicity, pregnancy, ischemia, hepatitis A infection, and Wilson disease, among other things.
In emergency medicine, ALF can pose serious dilemmas. While transplantation has drastically improved survival rates in recent decades, it is not always required, and no firm criteria for transplantation exist.
But delays in the decision to go ahead with a liver transplant can lead to death.
A new literature review aims to distill the decision-making process for emergency medicine practitioners. Knowing which candidates will benefit and when to perform transplantation “is crucial in improving the likelihood of survival,” its authors say, because of the many factors involved.
In a paper published online in May in The American Journal of Emergency Medicine (2017 May. doi. 10.1016/j.ajem.2017.05.028), Hamid Shokoohi, MD, and his colleagues at George Washington University Medical Center in Washington say that establishing the cause of acute liver failure is essential to making treatment decisions, as some causes are associated with poorer prognosis without transplantation.
“We wanted to improve awareness among emergency medicine physicians, who are the first in the chain of command for transferring patients to a transplant site,” said Ali Pourmand, MD, of George Washington University, Washington, and the corresponding author of the study. “The high risk of early death among these cases makes it necessary for emergency physicians to consider coexisting etiology, be aware of indications and criteria available to determine the need for emergent transplantation, and be able to expedite patient transfer to a transplant center, when indicated.”
As patients presenting with ALF are likely too impaired be able to provide a history, and physical exam findings may be nonspecific, laboratory findings are key in establishing both severity and likely cause. ALF patients in general will have a prolonged prothrombin time, markedly elevated aminotransferase levels, elevated bilirubin, and low platelet count.
Patients with ALF caused by acetaminophen toxicity (the most common cause of ALF in the United States) are likely to present with very high aminotransferase levels, low bilirubin, and high international normalized ratio (INR). Those with viral causes of ALF, meanwhile, tend to have aminotransferase levels of 1,000-2,000 IU/L, and alanine transaminase higher than aspartate transaminase.
Prognosis without transplantation is considerably poorer in patients with severe ALF caused by Wilson disease, Budd-Chiari syndrome, or idiosyncratic drug reactions, compared with those who experience viral hepatitis or acetaminophen toxicity.
Dr. Shokoohi and his colleagues noted that two validated scoring systems can be used to assess prognosis for severe ALF. The King’s College Criteria can be used to establish prognosis for ALF caused by acetaminophen, and ALF from other causes, while the MELD score, recommended by the American Association for the Study of Liver Diseases, incorporates bilirubin, INR, sodium, and creatinine levels to predict prognosis. Both of these scoring systems can be used to inform decisions about transplantation.
Finally, the authors advised that patients with alcoholic liver disease be considered under the same criteria for transplantation as those with other causes of ALF. “Recent research has shown that only a minority of patients ... will have poor follow-up and noncompliance to therapy and/or will revert to heavy alcohol use or abuse after transplant,” they wrote in their analysis. The researchers disclosed no outside funding of conflicts of interest related to their article.