1yr 3month old baby born out of a non-consanguineous marriage has been admitted to PICU with chief complaints of Vomiting and Poor appetite for 4 days, loose stool for 2 days and breathlessness for 1 day. Child had received symptomatic treatment on opd basis from outside. As her symptoms increased and started to have irritability, dehydration and breathing difficulty so she got admitted to an outside private hospital and received dehydration correction. Her blood gas was suggestive of severe metabolic acidosis (PH:6.9, Hco3 , Pco2: 9, lactate 0.6) .so referred to medicover hospital for further management.

Serum lactate was normal, and high uric acid level (11.4 mg/dl), serum ammonia 49.8 mcg/dl & urine ketone was 3 + in view of these reports and clinical findings child suspected to have an inborn error of metabolism.

The child was intubated and put on a mechanical ventilator, started on a metabolic cocktail ( multivitamins, SYP.carnisure, Inj. vit B12, cap co Q ), Iv bicarbonate corrections and bicarbonate-based iv fluids. As acidosis was severe and persistent in spite of bicarbonate correction so started on peritoneal dialysis with bicarbonate-based PD fluid.

In view of suspected IEM, metabolic blood & urine screen was sent ( NBS Tetra, Urine GCMS) and a report was suggestive of Beta-ketothiolase deficiency/2-Methyl-3-hydroxybutyryl CoA dehydrogenase deficiency. Clinical exome sequencing for HSD17B10/ACAT1 gene mutation analysis which was positive that also confirmed the diagnosis.

Acidosis resolved gradually on day 3 of PICU stay meanwhile she also received PRBC transfusion in view of low hemoglobin. As she was maintaining her vitals and acidosis resolved so sedation stopped and ventilator support tapered gradually.

On day 4 of PICU stay child started on special diet (low protein diet, maltodextrin and fruit juices) through NG tube Child oral intake has been improved, hemodynamically stable, urine ketones are nil so she had discharged on required multivitamin supplementations and a special diet.