PNLE Nursing Practice I (NP1) Practice Test

Vomiting leads to loss of gastric acid (hydrochloric acid) and chloride from the body. Losing hydrogen ions raises the body's pH, producing metabolic alkalosis, and the loss of chloride makes this a hypochloremic state. The accompanying volume depletion triggers renal mechanisms that conserve sodium and water but waste potassium, resulting in hypokalemia. So the classic pattern with vomiting is hypochloremic metabolic alkalosis with hypokalemia. In other scenarios, you’d see different patterns: loss of bicarbonate or chloride-rich fluids (as with some diarrheal losses or certain kidney disorders) tends to cause metabolic acidosis or hyperchloremia, not the hypochloremic alkalosis described here. Dehydration alone can occur with vomiting but doesn’t define the characteristic acid-base and electrolyte changes.