Acute Liver Failure (ALF)

Info

🌱 來自: Huppert’s Notes

Acute Liver Failure (ALF)🚧 施工中

Acute Liver Failure (ALF)

•   Definitions:

-   Acute liver injury (ALI): AST/ALT >100 IU/L

-   Acute liver failure (ALF): All three criteria must be present – 1) Coagulopathy (INR >1.5), 2) Hepatic encephalopathy, 3) No preexisting liver disease

•   Etiology:

-   Major causes: Ischemic hepatitis (e.g., shock liver, Budd-Chiari, hepatic artery thrombus or vasospasm), drug- or toxin-induced liver injury (e.g., acetaminophen, Amanita mushrooms), viral hepatitis, autoimmune hepatitis (See Table 4.9)

-   Other causes: Fulminant Wilson’s disease, malignancy with infiltration, pregnancy-related, hemophagocytic lymphohistiocytosis (HLH)

-   Conditions that do not typically cause ALF: Alcohol-related liver disease, hemochromatosis, NAFLD, alpha-1 antitrypsin deficiency, PSC, PBC

•   Workup:

-   Viral: Hepatitis A IgM, hepatitis B surface ag/ab/core, hepatitis C virus antibodies, hepatitis C RNA, HSV, EBV, CMV, varicella zoster antibodies, hepatitis E IgM

-   Other labs: Acetaminophen level, toxicology screen, ceruloplasmin, urine copper (patients <35 yr), pregnancy test, ANA, anti-SMA, IgG, HIV, amylase/lipase

-   Complete abdominal ultrasound with Doppler

-   If hepatic encephalopathy is present, consider NCHCT to rule out brain herniation

•   Complications: Neurologic (hepatic encephalopathy, herniation), pulmonary (ARDS), cardiac (high-output heart failure), hepatic (hypoglycemia, lactic acidosis, coagulopathy), bone marrow suppression, adrenal insufficiency, renal failure (thought to be due to cytokine-induced damage)

•   Prognosis: Multiple prognostic scoring systems are available (e.g., King’s College Criteria)

•   Treatment:

-   Supportive care:

•   N-acetylcysteine (NAC): Historically only used to treat acetaminophen-related ALF, but there is emerging evidence to consider use of NAC for all patients with ALF

•   Continuous renal replacement therapy (CRRT) if needed

•   Intracranial hypertension prevention/treatment if needed: Hypertonic saline and then mannitol, goal Na 145 mEq/L, elevate head of bed, intubate if needed

•   Prophylactic antibiotics

•   Phosphate repletion

•   Glucose monitoring/dextrose administration

•   Enteral feeding

•   Frequent neurologic checks. Of note, lactulose is not used to treat hepatic encephalopathy in ALF

-   Treat the underlying cause of ALF: See Table 4.9

TABLE 4.9 • Etiologies of Acute Liver Failure (ALF) and Recommended Treatments

-   Consider liver transplantation if low probability of recovery