Which of the following is NOT a cause of anion gap metabolic acidosis?

Anion gap metabolic acidosis occurs when there is an increase in the number of unmeasured anions in the serum, leading to a gap in the calculated anion gap. The causes of this condition typically include the accumulation of acids or ingestion of substances that produce acids, which contribute to a higher anion gap.

Methanol, uremia, and salicylates are all recognized causes of anion gap metabolic acidosis. Methanol is metabolized to formic acid, which increases the anion gap. Uremia occurs in kidney failure, where the accumulation of organic acids leads to a rise in the anion gap. Salicylates, particularly in high doses, can cause a metabolic acidosis by increasing lactic acid and interfering with normal acid-base balance.

Cardiac arrest, while a serious condition that can lead to metabolic acidosis, does not directly result in an anion gap increase. The acidosis associated with cardiac arrest is often due to lactic acidosis stemming from hypoperfusion and tissue hypoxia, which typically does not elevate the anion gap significantly. Thus, cardiac arrest is more related to non-anion gap acidosis or a mixed acidosis rather than directly contributing to an increased anion gap