King's College Criteria for Acetaminophen Toxicity

About the King's College Criteria

The King's College Criteria were developed to identify patients with acute liver failure who have a poor prognosis without liver transplantation. The criteria are divided into two sets: one for acetaminophen (paracetamol)-induced liver failure and another for non-acetaminophen-induced liver failure.

These criteria were developed at King's College Hospital in London and have been widely validated as prognostic indicators in acute liver failure.

Clinical Use

The King's College Criteria are used to identify patients with acute liver failure who are unlikely to survive without liver transplantation. They help guide decisions about the need for liver transplant evaluation and listing.

For acetaminophen-induced liver failure, the criteria have a high specificity but lower sensitivity, meaning that they are good at identifying patients who will die without transplantation but may miss some patients who could benefit from transplantation.

Criteria for Acetaminophen-Induced Liver Failure

Single criterion indicating poor prognosis:

• Arterial pH < 7.3 (or arterial lactate > 3.5 mmol/L after fluid resuscitation)

Or three or more of the following criteria:

• INR > 6.5 (or Prothrombin Time > 100 seconds)
• Serum creatinine > 3.4 mg/dL (300 μmol/L)
• Grade 3-4 encephalopathy (marked confusion to coma)
• Age > 40 years
• Time from ingestion to development of encephalopathy > 24 hours

Criteria for Non-Acetaminophen-Induced Liver Failure

Single criterion indicating poor prognosis:

• INR > 6.5 (or Prothrombin Time > 100 seconds)

Or three or more of the following criteria:

• Age < 10 or > 40 years
• Etiology: non-A, non-B hepatitis, drug-induced liver injury
• Duration of jaundice before encephalopathy > 7 days
• INR > 3.5 (or Prothrombin Time > 50 seconds)
• Serum bilirubin > 17 mg/dL (300 μmol/L)

Limitations

• The criteria have a high specificity but lower sensitivity for predicting mortality.
• They may not account for all factors that influence prognosis in acute liver failure.
• The criteria were developed before the widespread use of N-acetylcysteine for non-acetaminophen-induced liver failure.
• Other prognostic models, such as the MELD score, may provide additional information.

References

1. O'Grady JG, Alexander GJ, Hayllar KM, Williams R. Early indicators of prognosis in fulminant hepatic failure. Gastroenterology. 1989;97(2):439-445.
2. Bernal W, Donaldson N, Wyncoll D, Wendon J. Blood lactate as an early predictor of outcome in paracetamol-induced acute liver failure: a cohort study. Lancet. 2002;359(9306):558-563.
3. McPhail MJ, Wendon JA, Bernal W. Meta-analysis of performance of Kings's College Hospital Criteria in prediction of outcome in non-paracetamol-induced acute liver failure. J Hepatol. 2010;53(3):492-499.