A nurse is reviewing the medical records of four clients who have an acid-base imbalance. The nurse should recognize that which of the following clients is at risk for metabolic acidosis?

Choice A reason: Vomiting typically leads to metabolic alkalosis, not acidosis. It causes loss of hydrochloric acid from the stomach, reducing hydrogen ion concentration in the blood. This elevates blood pH above 7.45, as the body retains bicarbonate. The kidneys attempt to compensate by excreting excess bicarbonate, but this does not result in metabolic acidosis, making this choice incorrect. Choice B reason: Thiazide diuretics increase sodium and water excretion, which can lead to mild metabolic alkalosis due to increased bicarbonate reabsorption in the kidneys. They do not cause a loss of bicarbonate or accumulation of acids, which are necessary for metabolic acidosis. Thus, this choice is incorrect as it does not contribute to an acidic blood state. Choice C reason: Salicylate intoxication, such as from aspirin overdose, causes metabolic acidosis by increasing acid production. Salicylates stimulate the respiratory center, leading to hyperventilation and respiratory alkalosis initially, but they also disrupt mitochondrial function, causing lactic acid accumulation. This lowers blood pH below 7.35, meeting the criteria for metabolic acidosis, making this choice correct. Choice D reason: Diarrhea results in significant bicarbonate loss through the stool, as the intestines secrete bicarbonate to neutralize gastric acid. This loss reduces the blood’s buffering capacity, lowering pH below 7.35, indicative of metabolic acidosis. The body may attempt to compensate via hyperventilation to reduce CO2, but the primary issue is bicarbonate depletion, making this choice correct.