Acute metabolic decompensation: recognition and stabilisation

A term male infant is well at discharge on day 2 but returns on day 4 with poor feeding, vomiting, tachypnoea, and lethargy. He is hypotonic and grunting. Blood gas shows a high anion-gap metabolic acidosis with ammonia 360 µmol/L. Cultures are pending. The case walks the candidate through pattern recognition, the first-hour metabolic resuscitation (stop catabolism, clear the toxin, protect the brain), the indications and modality for dialysis, and the discharge planning that prevents the next crisis — including the written home emergency regimen and metabolic alert.