A child is brought to the pediatric clinic because he has been vomiting for the past 2 days. What acid-base imbalance would the nurse expect to occur from this persistent vomiting?

Choice A reason: Persistent vomiting causes loss of gastric acid (HCl), reducing hydrogen ions in the blood, leading to metabolic alkalosis (pH >7.45). The body compensates by retaining bicarbonate, exacerbating alkalosis. This is expected in a child with prolonged vomiting, as acid loss disrupts acid-base balance, requiring fluid and electrolyte correction. Choice B reason: Metabolic acidosis results from loss of bicarbonate or accumulation of acids, as in diarrhea or diabetic ketoacidosis. Vomiting causes loss of hydrogen ions, not bicarbonate, leading to alkalosis, not acidosis. This imbalance is inconsistent with the pathophysiology of persistent vomiting, making it an incorrect expectation. Choice C reason: Hyperkalemia is an electrolyte imbalance, not an acid-base disorder, and is not directly caused by vomiting. Vomiting may cause hypokalemia due to potassium loss in emesis. The question focuses on acid-base balance, making hyperkalemia irrelevant, as alkalosis is the expected outcome of prolonged vomiting. Choice D reason: Hypernatremia results from excessive sodium or water loss, not directly from vomiting, which primarily causes hydrogen and potassium loss. It is an electrolyte imbalance, not an acid-base disorder. Metabolic alkalosis from gastric acid loss is the expected imbalance, making hypernatremia incorrect for this clinical scenario.