Serial Lactic acid level in acetaminophen toxicity


Q: 22 year old female presented to ED after 4 hours of Tylenol (acetaminophen) toxicity. Lactic acid level is 5 mmol/L. After 12 hours it is 4 mmol/L. What does it signifies?



Answer: Poor prognosis

If lactate levels are high at 4 hours (more than 3.5 mmol/L) and remain elevated at 12 hours (more than 3.0 mmol/L) - are early predictors of outcome in acetaminophen-induced acute liver failure. Lactate levels are elevated as a result of both impaired tissue perfusion and decreased clearance by the liver.

Transfer to tertiary care center for transplant should be considered.



References:

1. Macquillan GC, Seyam MS, Nightingale P, Neuberger JM, Murphy N. Blood lactate but not serum phosphate levels can predict patient outcome in fulminant hepatic failure. Liver Transpl 2005; 11: 1073–1079.

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: 558–563.