UMEM Educational Pearls

Category: Toxicology

Title: Unexplained Lactic Acidosis, a clue to poisoning

Keywords: Lactic acidosis (PubMed Search)

Posted: 1/5/2017 by Kathy Prybys, DO (Emailed: 1/6/2017) (Updated: 1/6/2017)
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Lactic acidosis is the most common cause of anion gap metabolic acidosis in all hospitalized patients. An elevated lactate level is an important marker of inadequate tissue perfusion causing subsequent shift to anaerobic metabolism and occuring in a variety of disease states such as sepsis. In patients with unexplained lactic acidosis without systemic hyoperfusion or seizure suspect  the following toxins:

  • Acetaminophen: Early on in massive ingestion usually associated with coma.
  • Cyanide
  • Metformin
  • HIV Drugs: Nucleotide reverse transcriptase inhibitors = Didanosine, stavudine, zidovudine due to mitochondrial toxicity.
  • Ethylene Glycol: Spuriously elevated lactate may occur with ethylene glycol toxicity due to the structural similarity between glycolic acid and lactate.Check for osmolar gap.
  • Kombucha ``mushroom'' tea 



Understanding lactic acidosis in paracetamol (acetaminophen) poisoning. Shah, AD, Wood DM, et al. British Journal of Clinical Pharmacology 2011.71: 20–28.

Value of lactic acidosis in the assessment of the severity of acute cyanide poisoning. Baud FJ,  et al. Crit Care Med. 2002;30(9):2044-50.

The Importance of the osmolality gap in ethylene glycol intoxication. Oostvogels R, et al. BMJ 2013 Dec 7;347:31-33.

Can Acute overdose metformin lead to lactic acidosis? Wilis BK, et al. Amer J Emerg Med. 2010;28:857.

Bench to bedside review: Severe lactic acidosis in HIV patients treated with nucleoside analogue reverse transcriptase inhibitors. Classens Y-E, et al. Critical Care. 2003;7(3):226-232.

A case of Kombucha Teas Toxicity. Kole A SH, Jones HD, et al. J Intensive care Med.2009:24(3) 205-7.