Thanks Jared for a great case! This is a young person with a new diagnosis of celiac disease, recent hospitalization for pyelonephritis who is presenting with acute liver injury thought secondary to autoimmune hepatitis versus drug induced liver injury.
- ) We discussed the difference between the terms acute liver injury (ALI) and acute liver failure (ALF) (where acute = less than 6 months). Acute liver failure should satisfy the criteria:
- ) coagulopathy (INR>1.5)
- ) encephalopathy secondary to the liver disease
- ) no prior history of liver disease
- ) According to this paper from Hepatology that looked at ~150 patients with acute liver failure and 16 with Wilson’s disease, an AlkPhos: TBili ratio of less than 4 has a likelihood ratio of 23 supporting this diagnosis. However, the diagnosis is made by a combination of ceruloplasmin, slit lamp AND a 24-hour urine copper collection followed by liver biopsy.
- ) A differential for AST and ALT in the 1000’s is:
- ) drug induced liver injury (DILI) and toxins – classically acetaminophen, also salicylates and a whole list of drugs (livertox is a useful website)
- ) viruses – classically HAV, HBV, HCV and less commonly other hepatitis viruses, CMV, EBV, VZV, HSV, HIV
- ) ischemia (vascular/ shock liver) – shock liver, budd chiari, vaso-occlusive disease of the liver, etc
- ) autoimmune hepatitis
- ) other – ie wilson’s disease
Want to learn more?
Epidemiological considerations of etiology of acute liver failure
Note that although we think of drug induced liver injury as by far the most common cause of acute liver failure in adults in the US, the slices of the pie shift dramatically when we look globally and when we think about a more young adult population per these interesting pie graphs. It is always good to keep in mind this concept when thinking about "what is my pretest probability that this patient has acute liver failure from x ?"
Management of acute liver failure
We discussed key organ system dysfunctions that need to be addressed in acute liver failure include:
- coagulopathy – close monitoring of coagulopathy labs, consideration of thromboelastogram to guide transfusion
- hypoglycemia – extremely close monitoring of CBGs (start with q2hours) and consideration of dextrose infusion
- cerebral edema – consider head CT if patient develops severe encephalopathy; treatment would include raising the head of the bed, being careful with fluid boluses and consideration of hypertonic saline depending on degree of encephalopathy/ progression based serial CNS imaging studies
- encephalopathy - consider N-acetyl cysteine – although the drug of choice for acetaminophen associated DILI, a meta-analysis of 4 RCTs has shown it may be helpful in acute failure of any etiology; consider intubuation for airway protection if severe; lactulose and rifaximin are less effective
- infection risk - monitor closely for SIRS
Here is a great NEJM review article that goes over in detail the management of a critically ill patient with acute liver failure.