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: Pediatrics
[{'content': 'The metabolic derangement in congenital pyloric stenosis is – \nSelect and explain. \nA. Hypochloremic alkalosis, B. Hyperchloremic alkalosis, C. Hyperchloremic acidosis, D. Hypochloremic acidosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Clinical manifestations of congenital hypertrophic pyloric stenosis \n\nPyloric stenosis is usually not present at birth.\nNonbullous vomiting is the initial symptoms of pyloric stenosis.\nThe vomiting usually starts after 3 weeks of age, but symptoms may develop as early as the 1st week of life and as late as the 5 months of life.\nEmesis may follow each feeding, or it may be intermittent.\nAfter vomiting, the infant is hungry and wants to feed again.\nDue to vomiting, there is a progressive loss of→ Fluid, Hydrogen ion, Chlorides\nThis results in hypochloremic metabolic alkalosis.\nSerum potassium levels are usually maintained, but there may be a total body potassium deficit.\nJaundice (unconjugated bilirubin) is associated with a decreased level of glucuronyl transferase in 5% of patients.', 'role': 'assistant'}]