24: Acute Liver Failure

INTRODUCTION

Regardless of etiology, the unifying feature of acute liver failure (ALF) is a rapid, often precipitous, clinical course. Whereas spontaneous recovery of liver function is possible with supportive measures, particularly with acetaminophen overdose, there remains a significant risk of spiraling decline after presentation with multi-organ dysfunction, bleeding, and infectious complications often heralded by high-grade encephalopathy with cerebral edema.¹ A patient who presents emergently with ALF has an overall greater likelihood of either dying or requiring emergent orthotopic liver transplantation (OLT) than recovering without transplant.²

The key message for the emergency critical care practitioner is that early management of a patient with ALF requires an orchestrated team effort to rapidly and efficiently triage and mobilize management resources. Because of the rarity and complexity of ALF, it has been argued that ALF is best managed within the framework of a previously defined protocol, similar to the standards that have gained broad acceptance in stroke and acute coronary syndrome.³ Such team efforts are crucial to give the patient with ALF the best opportunity for transplant-free survival. In the setting of deteriorating status, teams are required to rapidly mobilize those resources, interventions, and caregivers that are crucial to provide stabilization and life support as well as rapid triage for transplantation in a crisis setting when the time course may not forgive hesitation.

Recommendations and best evidence for developing this approach have been published by the Acute Liver Failure Study Group (ALFSG)⁴ and the American Association for the Study of Liver Disease (AASLD).⁵ Both references consist of recommendations from a consortium of transplant centers that continue to prospectively collect data, report their findings, and grade the level of evidence.

This chapter is designed as a practical guide for the emergency critical care practitioner to manage ALF. An organizational framework for key clinical interventions is presented.

FIRST CONTACT: DEFINITION, RECOGNITION, AND DIAGNOSIS

Often used interchangeably, both the terms ALF and fulminant hepatic failure are defined by the new onset of hepatocellular dysfunction as reflected by coagulopathy (international normalized ratio [INR] >1.5) and encephalopathy in the absence of preexisting liver disease.⁶ By convention, the further stratification of fulminant hepatic failure is based on the rapidity of encephalopathy onset in the course of illness: less than 2 weeks for acute fulminant and 8 weeks for subfulminant.⁷ The ALFSG consortium has extended that time course up to 26 weeks for entry into their multicenter data analysis, and have adopted the term ALF, arguing that this captures the variable pace of illness in ALF, and better encompasses an extended range of patients who share epidemiologic, etiologic, physiologic, and management characteristics.⁸ In the absence of encephalopathy or coagulopathy, population-based studies of patients at risk of ALF have defined hepatotoxicity by ALT >1,000.⁹

How to Suspect the Diagnosis

As ...