A chemotherapy patient presents with fever, chills, productive cough, disorientation, hypotension, and an anion gap metabolic acidosis on labs. Which is the most likely explanation for the acidosis?

• A. Lactic acidosis
• B. Hyperglycemia
• C. Hyperchloremia
• D. Blast crisis

Answer: (A)

Lactic acidosis is the most likely cause here because this chemotherapy patient with fever, hypotension, disorientation, and pneumonia suggests sepsis with septic shock. In shock, tissues receive insufficient oxygen, so cells rely on anaerobic metabolism and produce excess lactate. Lactate accumulation increases the anion gap, leading to an anion gap metabolic acidosis.

Hyperglycemia can occur in stress, but it doesn’t routinely produce a high anion gap acidosis. Hyperchloremia tends to cause non‑anion gap (hyperchloremic) acidosis rather than an anion gap picture. Blast crisis involves leukemic progression rather than a rapid lactate-driven acidosis.