Friday June 1, 2007
Phosphate level in acetaminophen-induced acute liver failure

Case: You transferred a patient from nearby community hospital with acetaminophen-induced acute liver failure. ALT / AST reported in thousands and last PT-INR of 2.7. On clinical exam patient is alert and oriented. Hemodynamics are stable. You alerted the hepatology team and send STAT labs. After 45 minutes you received a call from lab with 'critical value' of phosphate with 0.9 mg/dl. Is it a good sign or a bad sign?

Answer: Good SignHypophosphatemia in the setting of acetaminophen-induced acute liver failure is a good sign. It indicates regeneration of hepatocytes and reversal of acute liver failure. You may have to replace it aggressively.Conversely, hyperphosphatemia suggest impaired regeneration and is a poor prognostic sign and actually also said to be a sign of impending hepato-renal failure due to kidney's lost ability of lowering of serum phosphate 1.

Related previous pearl: Is serum phosphate level better than King’s College Hospital criteria in Tylonol Toxicity ?


Reference: click to get abstract

1. Serum Phosphate Is an Early Predictor of Outcome in severe Acetaminophen-Induced Hepatotoxicity , Hepatology, Volume 36, Issue 3 , Pages 659 - 665