BS: Metabolic Acidosis: Differentiating the Causes in the Poisoned Patient

Metabolic acidosis may be a significant consequence of a vast array of toxins. Hence, determining which drugs or toxins might be responsible for metabolic acidosis in a patient with an unknown ingestion, accidental exposure, or exposure from therapeutic drug use can present daunting diagnostic and therapeutic challenges. More importantly, vital cellular functions and metabolic processes become impaired with increasing acidosis [1,2]. Therefore, it is paramount that clinicians recognize the substances that can result in metabolic acidosis so that timely and appropriate therapy may be instituted. Metabolic acidosis is defined as a process that lowers serum bicarbonate (HCO3 ) and occurs when Hþ ion production exceeds the body’s ability to compensate adequately through buffering or increased minute ventilation. Acidemia should not be confused with acidosis. Acidemia refers to a blood pH less than 7.40. Comprehensive discussion of acid-base disturbances is beyond the scope of this article, and the reader is referred elsewhere for further information [1,3,4]. Approach to the poisoned patient who has metabolic acidosis Evaluating a poisoned patient may pose numerous challenges to the treating physician. First, patients may present with altered mental status, Med Clin N Am 89 (2005) 1107–1124substantially limiting the ability to take an adequate history. Second, significant clues at the scene suggestive of the nature of the poisoning ma