II. Definitions
- Fulminant Hepatitis
- Rapid onset and progression within weeks to liver necrosis with secondary Hepatic Encephalopathy and Coagulopathy
- Acute Liver Failure
- Course of liver disease <=26 weeks, with INR >1.5, Hepatic Encephalopathy and no prior evidence of liver disease
III. Epidemiology
- Incidence: 2000 cases per year in the United States
IV. Pathophysiology
- Massive hepatic necrosis over the course of days to weeks
- Results in rapid progression from Jaundice to encephalopathy and Coagulopathy
- Multiorgan failure including Acute Renal Failure follows
V. Types
- Timing based on pregression from Jaundice onset to encephalopathy
- Acute Liver Failure within 1 week
- Hyperacute liver failure
- Acute Liver Failure within 1-4 weeks
- Acute Liver Failure
- Acute Liver Failure over >5-8 weeks
- Subacute liver failure
VI. Causes
- See Acute Hepatitis
- See Hepatotoxin
- Infectious Disease
-
Toxic Hepatitis
- Hepatotoxin exposure or other drug-induced cause
- Examples: Acetaminophen Overdose, Amanita muscaria ingestion
- Acute Ischemic Liver Injury (shock liver)
- Budd-Chiari Syndrome
- Idiopathic Chronic Active Hepatitis
- Wilson's Disease (Acute)
- Microvesicular Steatosis (Fat) Syndromes
VII. Symptoms
VIII. Signs
- Neurologic changes (Hepatic Encephalopathy)
- Altered Level of Consciousness (Delirium, coma)
- Decerebrate rigidity (with severe cerebral edema)
- Personality change
- Jaundice
-
Coagulopathy
- Bleeding (e.g. Gastrointestinal Bleeding)
- Acute Renal Failure (Hepatorenal Syndrome)
- Hypoglycemia
- Acute Pancreatitis
- Cardiopulmonary failure
- Ascites (due to Portal Hypertension)
IX. Labs
- See Acute Hepatitis
X. Imaging
- See Acute Hepatitis
XI. Management
- Targeted therapy
- Delivery for pregnancy related Acute Liver Disease (especially Acute Fatty Liver of Pregnancy)
- Withdraw all known Hepatotoxins
- Treat known Hepatotoxin exposures
- Consult with poison control and hepatology
- Consider empiric N-Acetylcysteine in possible acute Toxic Hepatitis
- Effective beyond Acetaminophen Overdose or Amanita muscaria ingestion
- Duration typically longer (>24 hours) than for Acetaminophen Overdose (per poison control)
- Supportive care
- ABC Management
- Endotracheal Intubation often required
- Fluid and Electrolytes
- Volume expansion with crystalloid initially, but avoid Fluid Overload
- Consider Albumin 25% at 50-100 ml aliquot or Albumin 5% at 250 ml aliquot
- Liver failure is associated with hypoalbuminemia
- Correct acid-base status and Electrolyte abnormalities
- Monitor Serum Glucose
- Correct Hypoglycemia with IV D10 or D20 prn
- Hemorrhagic Shock
- Consider FFP or PCC4 for Coagulopathy and severe active bleeding
- INR is not an accurate measure of bleeding risk in the absence of Warfarin
- Vasopressors
- Consider Vasopressin as a first-line Vasopressor in liver failure
- Volume expansion with crystalloid initially, but avoid Fluid Overload
- Prevent GI Bleed
- H2 Blockers to maintain gastric pH >3.5
- Monitor for infection
- Complicated by Bacterial or fungal infection in 80% of cases
- Infection is often occult with non-specific changes in status (e.g. worsening encephalopathy)
- Routinely monitor urine, Chest XRay and other markers of infection
- Have low threshold to start Antibiotics and Antifungals
- Consider prophylactic Antibiotics (e.g. Ceftriaxone)
- Hepatic Encephalopathy
- Increased risk for cerebral edema, intracranial Hypertension and Uncal Herniation
- Monitor Hepatic Encephalopathy patients in ICU
- Hepatic Encephalopathy may be more severe in Acute Liver Failure than in longstanding Cirrhosis
- Obtain Head CT and Ocular Ultrasound for Optic Nerve Sheath Diameter
- General measures
- Consider Endotracheal Intubation
- Elevate head of bed to 30 degrees
- Control systemic Hypertension
- Lactulose (oral, rectal) lowers cerebral ammonia and may decrease ICH
- Other measures for lowering Intracranial Pressure (questionable efficacy unless temporizing for procedure)
- Lower Intracranial Pressure with Mannitol IV or Hypertonic Saline prn (while replacing urine losses)
- ABC Management
- Transfer to center capable of performing Liver Transplant (if potential candidate)
- See Liver Transplant Center Referral Indications
- Other Liver Transplant referral indications
- Grade 3-4 Encephalopathy
- Adverse prognostic indicators as above
XII. Prognosis: Factors associated with poor outcomes
- Advanced age
- Halothane exposure
- Hepatitis C
- Coma (80% Mortality)
- Rapid decrease in liver span
- Respiratory Failure
- Marked ProTime prolongation
- Factor V Level <20%
XIII. References
- Swaminathan and Weingart in Herbert (2020) EM:Rap 20(10):1-2
- Swencki (2015) Crit Dec Emerg Med 29(11):2-10
- Swencki (2023) Crit Dec Emerg Med 37(8):4-12