What is the King's College Criteria used for?

The KCC identifies patients with acute liver failure (ALF) who have a poor prognosis for spontaneous recovery and should be considered for emergency liver transplantation. Meeting either acetaminophen pathway (pH 6.5 or any three of the five clinical factors) indicates high mortality without transplant.

How do the acetaminophen and non-acetaminophen criteria differ?

For acetaminophen ALF, meeting ANY ONE criterion (arterial pH 6.5 + creatinine > 3.4 mg/dL + Grade III/IV encephalopathy) indicates poor prognosis. For non-acetaminophen ALF, the criteria involve INR, bilirubin, age, etiology, and jaundice-to-encephalopathy interval.

When should arterial pH be measured for the acetaminophen criteria?

Arterial pH should be measured after adequate fluid resuscitation, at least 24 hours after the acetaminophen overdose. A pH < 7.30 at this point is a single-criterion predictor of poor outcome.

What hepatic encephalopathy grades qualify?

Grade III encephalopathy presents with marked confusion, drowsiness, and incomprehensible speech. Grade IV is coma. Both Grade III and IV together with elevated INR and creatinine meet the acetaminophen KCC.

What does "criteria not met" mean clinically?

"Criteria not met" suggests the patient has a better chance of spontaneous recovery, but does not guarantee survival. Intensive supportive care should continue and the patient should be reassessed frequently as their condition can evolve.

How accurate are the King's College Criteria?

The KCC have high specificity (approximately 90–95%) for predicting death without transplant, meaning a positive result strongly predicts poor outcome. Sensitivity is lower (~50–70%), so some patients who would die may not be identified. They remain the most widely validated tool for this indication.

King's College Criteria for Liver Failure

Enter lab values and clinical data to determine whether a patient with acute liver failure meets King's College criteria for liver transplant consideration.

Patient Data

For clinical decision support only. Always apply clinical judgment.

Etiology

Arterial pH (after fluid resuscitation, >24 h post-overdose)

Criterion: pH < 7.30

Combined criterion (all three must be present):

INR (Prothrombin time ratio)

Criterion: INR > 6.5

Serum Creatinine

Criterion: > 3.4 mg/dL (300 µmol/L)

Hepatic Encephalopathy Grade

Criterion: Grade III or IV

Quick Reference

Acetaminophen ALF — meets criteria if:

Arterial pH < 7.30 (after resuscitation, >24 h post-ingestion)
— OR all three of —
INR > 6.5 + Creatinine > 3.4 mg/dL + Encephalopathy Grade III/IV

Non-Acetaminophen ALF — meets criteria if:

INR > 6.5 (any etiology)
— OR any three of —
INR > 3.5
Bilirubin > 17.4 mg/dL (300 µmol/L)
Age < 10 or > 40 years
Unfavorable etiology (Wilson's, drug-induced, seronegative)
Jaundice-to-encephalopathy interval > 7 days

Source: O'Grady JG et al. Early indicators of prognosis in fulminant hepatic failure. Gastroenterology 1989;97(2):439–445.

Clinical disclaimer: This tool is for educational and clinical decision-support purposes only. It does not replace clinical judgment, institutional protocols, or specialist consultation. Always verify lab values and apply full clinical context when evaluating acute liver failure.

Summary

Enter lab values and clinical data to determine whether a patient with acute liver failure meets King's College criteria for liver transplant consideration.

How it works

Select the etiology: acetaminophen (paracetamol) overdose or non-acetaminophen cause.
Enter the required lab values and clinical data for the chosen etiology.
The calculator checks whether any single criterion or the required combination is met.
A result of "Criteria Met" indicates a poor prognosis and transplant listing should be considered.
A result of "Criteria Not Met" suggests a better chance of spontaneous survival, but continue monitoring.
Always interpret results in full clinical context — the criteria are a guide, not a replacement for clinical judgment.

Use cases

Emergency physicians evaluating acute liver failure patients.
Hepatologists determining candidacy for emergency liver transplantation.
Intensivists managing patients with fulminant hepatic failure in the ICU.
Medical students and residents learning prognostic criteria for ALF.
Clinical pharmacists assessing acetaminophen toxicity severity.
Toxicologists evaluating paracetamol overdose prognosis.

Frequently Asked Questions

Last updated: 2026-09-19 · Reviewed by Nham Vu