Which substance is used to correct metabolic acidosis and manage certain toxicological emergencies?

• A. Magnesium sulfate
• B. Sodium bicarbonate
• C. Thyroid hormone
• D. Vaccines

Answer: (B)

Sodium bicarbonate acts as a buffer to correct metabolic acidosis and can help in certain toxicologic emergencies by alkalinizing the urine. When metabolic acidosis occurs, there’s an excess of hydrogen ions and a deficiency of bicarbonate. Providing bicarbonate supplies the base needed to neutralize the excess hydrogen ions, raising the pH, and allowing the buffering system to restore balance. In toxicology, increasing the urine pH makes weak acid toxins more ionized in the renal tubule, reducing their reabsorption and enhancing their elimination. This approach is particularly useful in cases like salicylate poisoning and ingestion of methanol or ethylene glycol.

Magnesium sulfate has other clinical uses and isn’t used to correct acidosis or manage these poisonings. Thyroid hormone and vaccines do not address acid-base balance or toxin excretion.