Acute hepatic failure: Difference between revisions

(Text replacement - "IV drug use " to "IV drug use")
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**[[Verapamil]]
**[[Verapamil]]
===Other Rare Causes of Acute Liver Failure===
===Other Rare Causes of Acute Liver Failure===
*'''Wilson’s disease''': unexplained elevations in LFTs, neuro-psychiatric symptoms, Kayser-Fleischer rings on eye exam
*'''[[Wilson's disease]]''': unexplained elevations in LFTs, neuro-psychiatric symptoms, Kayser-Fleischer rings on eye exam
*'''Auto-immune hepatitis''': more common in women, liver disease without explanation, may have family history of other autoimmune disorders
*'''[[Autoimmune hepatitis]]''': more common in women, liver disease without explanation, may have family history of other autoimmune disorders
*'''Hemochromatosis''': family history of liver disease and cardiac disease
*'''[[Hemochromatosis]]''': family history of liver disease and cardiac disease
*'''Budd-Chiari''': history of hypercoagulable disorder, abdominal pain, and ascites
*'''Budd-Chiari''': history of hypercoagulable disorder, abdominal pain, and ascites
*'''Infections''': [[HSV]], [[Epstein-Barr virus]], [[varicella zoster virus]], [[toxoplasmosis]]
*'''Infections''': [[HSV]], [[Epstein-Barr virus]], [[varicella zoster virus]], [[toxoplasmosis]]
==Clinical Features==
==Clinical Features==
*Common findings in acute liver failure
*Common findings in acute liver failure
**Tender hepatomegaly
**Tender [[hepatomegaly]]
**[[Jaundice]]
**[[Jaundice]]
**Encephalopathy
**[[Hepatic encephalopathy]]
**Asterixis
**Asterixis
*Common findings in chronic liver failure
*Common findings in chronic liver failure
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*[[Hypoglycemia]]
*[[Hypoglycemia]]
*[[Hypoxia]]
*[[Hypoxia]]
*Intracerebral hemorrhage or mass
*[[Intracerebral hemorrhage]] or mass
*[[Meningitis]]/[[encephalitis]]
*[[Meningitis]]/[[encephalitis]]
*[[CVA]]
*[[CVA]]
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*[[Hepatitis]]
*[[Hepatitis]]
*Hemolysis
*Hemolysis
*Biliary pathology (CBD obstruction)
*[[Biliary disease]] (e.g. [[Choledocholithiasis|CBD obstruction]])
*[[Pregnancy]]
*[[Pregnancy]]
*[[Congenital diseases]] (more likely to present in early childhood)
*Congenital diseases (e.g. [[inborn errors of metabolism]]; (more likely to present in early childhood)


{{Ascites DDX}}
{{Ascites DDX}}
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==Evaluation==
==Evaluation==
===Labs===
===Labs===
*AST and ALT
*[[LFTs]]
**Enzymes found mainly in hepatic cells, though ALT is more specific to the liver than AST
**AST and ALT
**Extreme elevation in AST (>3000U/L, or >40x upper limit of normal) is consistent with acetaminophen toxicity or ischemic injury
***Enzymes found mainly in hepatic cells, though ALT is more specific to the liver than AST
**Moderate elevations (10-40x upper limit of normal) is consistent with viral hepatitis
***Extreme elevation in AST (>3000U/L, or >40x upper limit of normal) is consistent with acetaminophen toxicity or ischemic injury
**Mild elevations (<10x upper limit of normal) is consistent with alcoholic hepatitis
***Moderate elevations (10-40x upper limit of normal) is consistent with viral hepatitis
*Alkaline Phosphatase
***Mild elevations (<10x upper limit of normal) is consistent with alcoholic hepatitis
**Found in bile canaliculi (but also in placenta, ileal mucosa, bone, and kidney)
**Alkaline Phosphatase
**Elevated in diseases of cholestasis
***Found in bile canaliculi (but also in placenta, ileal mucosa, bone, and kidney)
**Rare for levels to be >3x normal limit in acute liver failure
***Elevated in diseases of cholestasis
*Bilirubin
***Rare for levels to be >3x normal limit in acute liver failure
**Elevated in diseases of cholestasis
**Bilirubin
**In obstructive diseases, the direct bilirubin will usually be about 50% of the total bilirubin; if indirect bilirubin is higher, more suggestive of hemolysis or problem with conjugation
***Elevated in diseases of cholestasis
***In obstructive diseases, the direct bilirubin will usually be about 50% of the total bilirubin; if indirect bilirubin is higher, more suggestive of hemolysis or problem with conjugation
*Coagulation Studies
*Coagulation Studies
**Reflects the liver’s ability to synthesize clotting factors
**Reflects the liver’s ability to synthesize clotting factors
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**Only need to test for IgM anti-HEV in patients who are symptomatic and have just travelled from areas where Hepatitis E is endemic
**Only need to test for IgM anti-HEV in patients who are symptomatic and have just travelled from areas where Hepatitis E is endemic
===Imaging===
===Imaging===
*Consider US or CT in patients with jaundice to evaluate for a mechanical obstruction
*Consider [[RUQ US]] or CT in patients with jaundice to evaluate for a mechanical obstruction
*Otherwise, tailor imaging towards specific complaints
*Otherwise, tailor imaging towards specific complaints
==Management==
==Management==
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*Early consideration regarding transporting patient to a transplant center given potential for rapid deterioration
*Early consideration regarding transporting patient to a transplant center given potential for rapid deterioration
*Symptom specific supportive treatment options
*Symptom specific supportive treatment options
**Encephalopathy: consider [[lactulose]] of [[neomycin]]
**[[Hepatic encephalopathy|Encephalopathy]]: consider [[lactulose]] of [[neomycin]]
**[[Seizures]]: consider [[phenytoin]] over [[benzodiazepines]] (prevent benzodiazepine oversedation secondary to decreased hepatic clearance)
**[[Seizures]]: consider [[phenytoin]] over [[benzodiazepines]] (prevent benzodiazepine oversedation secondary to decreased hepatic clearance)
**[[Increased ICP|Intracranial Hypertension]]: elevated head of bed, [[mannitol]], short-term hyperventilation; hypothermia may be a bridge to transplant; no benefit from steroids
**[[Increased ICP|Intracranial Hypertension]]: elevated head of bed, [[mannitol]], short-term hyperventilation; hypothermia may be a bridge to transplant; no benefit from steroids
**Coagulopathy
**Coagulopathy
***Prophylactic normalization of the INR is not necessary unless procedure (such as paracentesis) is planned; then can give [[Vitamin K]]
***Prophylactic normalization of the INR is not necessary unless procedure (such as paracentesis) is planned; then can give [[Vitamin K]]
***Recommend platelet transfusion to 10K for asymptomatic patients, and to 50-70K for patients undergoing invasive procedures
***Recommend [[platelet transfusion]] to 10K for asymptomatic patients, and to 50-70K for patients undergoing invasive procedures
**See [[Acetaminophen toxicity]] for specifics regarding treatment of acetaminophen toxicity
**See [[Acetaminophen toxicity]] for specifics regarding treatment of acetaminophen toxicity
**See [[Spontaneous Bacterial Peritonitis]] for specifics regarding diagnosis and treatment of SBP
**See [[Spontaneous Bacterial Peritonitis]] for specifics regarding diagnosis and treatment of SBP

Revision as of 18:50, 27 January 2019

Definitions[1]

  • Hyperacute liver failure: encephalopathy occurs within 7 days of the onset of jaundice; this subset is likely to survive with medical management despite the high incidence of cerebral edema
  • Acute liver failure: interval of 8-28 days from jaundice to encephalopathy; this subset has a high incidence of cerebral edema and a poorer prognosis without liver transplant
  • Subacute liver failure: interval of 5-12 weeks from the onset of jaundice to the onset of encephalopathy; this subset has a lower incidence of cerebral edema, but a poor prognosis

Causes

Acetaminophen Toxicity

  • Now the most common cause of acute liver failure in the US[2]
  • Small amount of acetaminophen is metabolized by CytochromeP450 into NAPQI, which is a toxic metabolite
  • In therapeutic doses, NAPQI combines rapidly with glutathione to form nontoxic metabolites that are excreted in the urine
  • In overdose, glutathione stores are used up and NAPQI binds to cell proteins in the liver which leads to cell death
  • See Acetaminophen toxicity

Viral Hepatitis

  • Hepatocellular pattern of injury, where AST and ALT are higher than Tbili and Alk Phos; likely to have significantly elevated ALT and AST (20x normal or higher)
  • Of note, transmission of Hepatitis B and Hepatitis C through donated blood, blood products, and organs is rare in the US since blood screening became available in 1992
  • Hepatitis A
    • Fecal-oral transmission
    • Associated with epidemics linked to a common source (water)
    • Most common risk factor is travel outside of the US [3]
    • Not associated with chronic carrier state; incubation period is approximately 30 days, and infectivity usually resolved prior to symptom onset
  • Hepatitis B
    • Transmitted parenterally, blood contact, and unprotected sex
    • 90% of exposed infants progress to chronic hepatitis; 10% of exposed adults progress to chronic hepatitis
    • Serology[4]
Clinical Scenario HBsAg anti-HBc anti-HBs
Susceptible to infection negative negative negative
Immune due to natural infection negative positive positive
Immune due to Hep B infection negative negative positive
Acutely infected positive anti-HBc- positive; IgM anti-HBc- positive negative
Chronically infected positive anti-HBc- positive; IgM anti-HBc- negative negative
  • Hepatitis C
    • Transmitted through IV drug use(most common) and infrequently through sexual contact
    • 90% of HCV infections progress to chronic hepatitis[5]
  • Hepatitis D
    • Transmission similar to Hepatitis B
    • Can only co-infect patients with Hepatitis B (actively producing HBsAg)
    • Presentation can range from acute self-limited disease to fulminant hepatitis or chronic infection
  • Hepatitis E
    • Fecal-oral transmission
    • Usually results in mild illness, but can cause fulminant hepatitis in pregnant women[6]

Alcohol-related Liver Disease and Alcoholic hepatitis

  • Presentation can range from mild abdominal pain, nausea and vomiting to acute liver failure
  • May have large palpable liver from fatty infiltration, or may have small nonpalpable liver secondary to cirrhosis from chronic disease
  • Will have moderate elevations in AST and ALT (levels >10x normal are unusual)
    • AST:ALT ration >2 is typical
  • May also have electrolyte abnormalities from malnutrition or alcoholic ketoacidosis

Drug or Toxin Related Liver Disease

Other Rare Causes of Acute Liver Failure

Clinical Features

  • Common findings in acute liver failure
  • Common findings in chronic liver failure
    • Ascites
    • Caput medusae
    • Palmar erythema
    • Spider angiomata
    • Gynecomastia
    • Testicular atrophy
    • Parotid gland enlargement
    • Muscular atrophy
    • May also have jaundice, encephalopathy, and asterixis as in acute liver failure

Differential Diagnosis

Encephalopathy (altered mental status)

Jaundice


  1. REDIRECT Template:Ascites Evaluation

Evaluation

Labs

  • LFTs
    • AST and ALT
      • Enzymes found mainly in hepatic cells, though ALT is more specific to the liver than AST
      • Extreme elevation in AST (>3000U/L, or >40x upper limit of normal) is consistent with acetaminophen toxicity or ischemic injury
      • Moderate elevations (10-40x upper limit of normal) is consistent with viral hepatitis
      • Mild elevations (<10x upper limit of normal) is consistent with alcoholic hepatitis
    • Alkaline Phosphatase
      • Found in bile canaliculi (but also in placenta, ileal mucosa, bone, and kidney)
      • Elevated in diseases of cholestasis
      • Rare for levels to be >3x normal limit in acute liver failure
    • Bilirubin
      • Elevated in diseases of cholestasis
      • In obstructive diseases, the direct bilirubin will usually be about 50% of the total bilirubin; if indirect bilirubin is higher, more suggestive of hemolysis or problem with conjugation
  • Coagulation Studies
    • Reflects the liver’s ability to synthesize clotting factors
    • INR >6.5 or PT >20 seconds indicates patients at high risk for death
  • Albumin
    • Reflects synthetic function of the liver
    • Has a long half-life (20 days) and may not be decreased early in disease
  • Ammonia
    • Elevated as a result of impaired clearance
    • Poor correlation between degree of elevation and severity of encephalopathy symptoms
  • Chemistry Panel
    • Electrolyte abnormalities may indicate malnutrition or dehydration
    • Creatinine is used as a prognostic indicator
    • Need to check a glucose because patients with liver failure are prone to hypoglycemia
  • CBC
    • Not useful in diagnosing the cause of liver failure, but helpful in determining coexisting infection, anemia, thrombocytopenia
  • Hepatic Viral Serologies
    • Consider for all patients with undifferentiated liver failure
    • IgM anti-HBc may be the only positive marker in acute Hepatitis B infection
    • Anti-HCV and HCV RNA are present in both chronic and acute Hepatitis C infections, so it is difficult to differentiate based on serologies, but presence of HCV RNA in the absence of anti-HCV is more suggestive of acute infection[8]
    • Only need to test for IgM anti-HEV in patients who are symptomatic and have just travelled from areas where Hepatitis E is endemic

Imaging

  • Consider RUQ US or CT in patients with jaundice to evaluate for a mechanical obstruction
  • Otherwise, tailor imaging towards specific complaints

Management

  • Treatment is mostly supportive and tailored towards the specific etiology
  • Early consideration regarding transporting patient to a transplant center given potential for rapid deterioration
  • Symptom specific supportive treatment options

Disposition

  • Admission to ICU with early consideration for transportation to transplant center

See Also

References

  1. ↑ O’Grady, JG, Schalm SW, Williams R. Acute liver failure: redefining the syndromes. Lancet. July 1993, Volume 342, Issue 8866, Page 273-275
  2. ↑ Ostapowicz G, Fontana RJ, Schiodt FV, et al. Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States. Ann Intern Med. 2002 Dec 17; 137(12): 947-54.
  3. ↑ Oyama, LC: Disorders of the Liver and Biliary Tractin Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 107: p 1186-1204.
  4. ↑ www.cdc.gov/hepatitis
  5. ↑ Oyama, LC: Disorders of the Liver and Biliary Tractin Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 107: p 1186-1204
  6. ↑ Rein DB, Stevens GA, Theaker J, Wittenborn JS, Wiersma ST. The Global Burden of Hepatitis E Virus Genotypes 1 and 2 in 2005. Hepatology, Vol. 55, No. 4, 2012: 988-997
  7. ↑ Oyama, LC: Disorders of the Liver and Biliary Tractin Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 107: p 1186-1204
  8. ↑ Bailey, C, Hern HG. Hepatic Failure: An Evidence-Based Approach In The Emergency Department. Emergency Medicine Practice. Vol. 12, No. 4, 2014.
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