This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Persistent vomiting in G.O.O. causes - 
Select and explain. 
A. Hyponatremic hyperchloremia occur, B. Hypernatremia without led Cl- alkalosis, C. Hypokalemic metabolic alkalosis, D. All
C: Hypokalemic metabolic alkalosis
Answer: C: Hypokalemic metabolic alkalosis 
Explanation: Answer is 'c' i.e. Hypokalemic metabolic alkalosis Repetitive vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria) Cause of paradoxical aciduria Initially the kidney compensate for metabolic alkalosis by reabsorbing hydrogen and chloride ions in exchange for sodium, potassium and bicarbonate. But gradually as the body stores of sodium and especially potassium become depleted, kidney stas retaining these ions in exchange of hydrogen ions, thus the urine becomes acidic and metabolic alkaline state is fuher aggravated.