The INR conveys the synthetic function of the liver and is the most accurate marker for severity of liver damage. Poor prognostic signs, and thus indications for transfer to a liver unit include:
INR > 2 within 48 hours
INR > 3.5 within 72 hours
Signs of encephalopathy
Creatinine > 300 μmol/l (studies have shown a survival rate of 23% in patients with Cr > 300μmol/l)
Blood pH < 7.3
SBP < 80 mmHg
Liver enzymes are a poor marker of the degree of hepatocellular damage.
Paracetamol overdose causes hepatic injury through its reactive metabolite N-acetylbenzoquinoneimine (NAPQI), which is normally rapidly detoxified by glutathione in liver cells. In overdose, NAPQI production exceeds glutathione capacity, and the metabolite reacts directly with hepatic macromolecules, causing liver injury. Renal damage may occur by the same way, owing to renal P450 metabolism. Ingestion of more than 6-7 g in adults is potentially hepatotoxic.
Treatment includes oral activated charcoal if the patient presents within 3-4 hours of ingestion. Antidotal treatment is with N-acetylcysteine (Parvolex®). Methionine can be used in patients allergic to N-acetylcysteine
Pastest
Paracetamol overdose
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Dr.Sudan
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