A 3-year-old ingests an unknown quantity of his grandfather's metformin. Six hours later he develops worsening tachypnea, altered sensorium, and blood lactate of 12 mmol/L with anion gap metabolic acidosis. The MOST effective treatment is:

• A Activated charcoal and supportive IV fluids
• B Sodium bicarbonate infusion to correct acidosis
• C Emergent hemodialysis ✓
• D N-acetylcysteine infusion

Explanation

Metformin-associated lactic acidosis (MALA) with severe hyperlactatemia (>10 mmol/L), profound metabolic acidosis, and hemodynamic compromise is an indication for emergent hemodialysis. Hemodialysis simultaneously removes metformin (which is dialyzable), corrects lactate, and addresses acidosis. Activated charcoal is only useful within 1-2 hours of ingestion; this child is 6 hours post-ingestion. Bicarbonate infusion alone treats the consequence but not the underlying cause. N-acetylcysteine has no role in metformin toxicity.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.