Acute liver failure-Dr. Wu's liver diseases (Hepatitis, ...)

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(Established in March 1996) liver-diseases

Acute liver failure

Dr. Wu's Liver diseases
for professionals (medical students and residents)

(by Jau-Shin WU, M.D., Ph.D.)

(Posted Sep. 16, 1996; Updated May 14, 2009)

Acute liver failure

For consumers:

(Key words: acute liver failure, fulminant hepatitis, fulminant hepatic failure, superacute liver failure, subacute liver failure)

Acute liver failure is a clinical condition that result from severe and extensive damage of liver cells leading to failure of the liver to fucntion normally and induce mental confusion of various degree.
It is caused by various kinds of diseases, therefore it is called a syndrome (a similar clinical condition caused by different diseases).
It is a very severe clinical condition with high mortality rate, but when patients recover, they will recover completely.
The symptoms are: icterus or jaundice (yellowish change of skin and mucosa color), and mental confusion and loss of different degree.
The shorter the interval from onset of icterus to onset of mental confusion, the better the outcome appears to be.

For professionals:

Acute liver failure is a clinical syndrome that results from massive necrosis of livr cells leading to hepatic encephalopathy and severe impairement of hepatic function.
It is caused by different kinds of diseases, such as viral hepatitis (A, B, C, ...), drugs, intoxication, autoimmne hepatitis, and etc.
It has diverse clinical courses and etiological factors, therefore, various classifications have been proposed with some degree of overlaps.

Perplexity in Terminology:

Fulminant Hepatic Failure (FHF)
Acute liver failure
"Acute" vs "Fulminant"; "liver" vs "hepatic"

Lucke and Mallory (1946):

Two types of acute hepatitis:

1) fulminant form with an extremely rapid outcome
2) subacute form with a slower course

Trey (1970; USA):

Fulminant hepatic failure:
potentially reversible condition
consequence of severe liver injury
with an onset of encepalopathy within 8 weeks of the appearance of the first symptoms
absence of pre-existing liver disease.

Bernuau and Benhamou (1986; 1993; Paris):

Fulminant hepatic failure
development of encephalopathy within 2 weeks after the onset of jaundice

Subfulminant liver failure

2 weeks to 12 weeks

cause, age, and prothrombin or factor V level is more accurate than that based only on the interval between the onset of jaundice and encephalopathy
Bernuau also suggested the term "Severe acute liver failure" for a case with:

a greater than 50 % decrease in normal coagulation factors concentration without the development of hepatic encephalopathy.
as soon as encephalopathy develops, uses the term "fulmiant or subfulminant liver failure"

O'Grady (1993; London):

classification: (encephalopathy appears ~wks within or after the onset of the first symptoms)

Hyperacute liver failure ( within 1 week),
acute liver failure( 2 to 4 weeks) and
subacute liver failure ( 5 to 12 weeks).

survival rate with medical management :

HALF : ALF : SALF = 36 % : 7 % : 14 % = incidence of cerebral edema (H : H : L)

encepahalopathy: mandatory clincal feature
include cases of pre-existing synptomless chronic liver conditions

both groups accept the fact that the survival rate is greater in those cases with a shorter interval between onset of the first symptom and encephalopathy.

Japan:

Two groups -- Encephalopathy occur within and over 10 days after onset
Shorter interval -- better pgognosis

Acharya SK (1996; India)

Pregnancy, cause, and rapidity of onset of encephalopathy did not influence survival

Questions on evaluation of the prognosis of FHF -- to estimate probability of spontaneous recovery

Completely reversible condition
FHF case with stage 3~4 encephalopathy -- medical therapy alone -- poor prognosis
Orthotopic liver transplantation (OLTx) -- survival rate: 60~80% -- lifelong immunosuppressive therapy
Timing -- when to perform OLTx -- critical for successful OLTx
Predictive factors for survival:

Static variables: age, race, gender, cause
Dynamic variables: degree of come, serum bilirubin, prothrombin time, factor V

Etiology:

HAV, HBV, HCV, HEV, HDV, HSV, CMV, EBV, HZV, drug-induced, toxic, concommitant use of enzyme-inducing drugs and chronic alcohol ingestion aaggravate paracetamol-induced liver injury, afratoxin, herbs, ischemic liver cell necrosis, hypovolemic or septicemic shock, hepatic artery thrombosis, Budd-Chiary syndrome, veno-occlusive disease of the liver, microvesicular steatosis in pregnancy, Ray's syndrome, liver transplantation.

Clinical presentation:

Hepatic encepahlopathy:

stupor or coma
fector hepaticus
flapping remor
raised blood ammonia.

Cerebral edema:

vasogenic - disruption of blood-brain barrier.
cytogenic edema - loss of capacity of neuroglial cells to maintain solute and water homeostasis.
increase of intracranial pressure.

Hemorrhage:

platelet - decrease
coagulation factors - decrease (factor V, VII, XIII, fibrinogen)
antithrombin III, alpha-2 macroblobulin - decrease
fibrinolysis and DIC
prothrombin-T, PTT

Infection and immunity:

bacteremia, septicemia, endotoxemia.
cytokines - increase (IL-1, TNF,)

Biochemical change:

transaminase
alpha-fetoprotein - regeneration
hyponatremia
hypokalemia
hypophosphatemia
hypocalcemia
hypomagnesemia

References

[Dr. Wu's Health Note- Home] [Taiwan Medical Network]
[Web sites for medical students][Curriculum Vitae ]
(By Jau-Shin Wu, M.D.; Posted Sep. 16, 1996; Revised May 12, 2009)

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(Dr. Wu's Liver D) Since Jan. 01, 2008
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