King’s College Criteria for Acetaminophen Toxicity

Provides lab-based recommendations for who should be immediately referred for liver transplant after acetaminophen overdose.

Lactate > 3.5 mg/dL (0.39 mmol/L) 4 hrs after early fluid resuscitation?
pH < 7.30 or lactate > 3 mg/dL (0.33 mmol/L) after full fluid resuscitation at 12 hours
INR > 6.5 (PTT > 100s)
Creatinine > 3.4 mg/dL (300 µmol/L)
Grade 3 or 4 Hepatic Encephalopathy?
Phosphorus > 3.75 mg/dL (1.2 mmol/L) at 48 hours
  • Grade 1 - Inverted sleep pattern; forgetfulness, mild confusion, agitation, irritability, tremor, apraxia
  • Grade 2 - Lethargy, slow responses; Disorientation for time or place, Subtle personality change; Asterixis, dysarthria, ataxia
  • Grade 3 - Somnolence but rousability, Disorientation as regards place; Asterixis, hyperactive reflexes, Babinski signs, muscle rigidity
  • Grade 4 - Coma (unresponsive to verbal or noxious stimuli)








The NNT : Quick Summaries of Evidence-Based Medicine