Anaesthetic considerations in a child with methylmalonic acidemia and its literature review.

Methyl malonyl coenzyme A mutase deficiency is a rare autosomal inherited inborn error in branched-chain amino acid metabolism characterised by the accumulation of methylmalonic acids. There is relative paucity of literature regarding anaesthetic management of these children presenting for incidental major abdominal surgery. Preoperative management includes goal-directed correction of dehydration, metabolic acidosis and hyperammonemia. Anaesthetic goals include avoidance of factors that can trigger metabolic crisis like hypercapnia, hypothermia, hypoxia, surgical stress, hypovolaemia, hypotension and so on. Herein, we are reporting the anaesthetic management of a 17-month-old child with methylmalonic acidemia (MMA) posted for a major upper abdominal surgery for excision of an adrenal mass, which was incidentally diagnosed during admission for an episode of metabolic crisis. We aim to highlight the specific nuances of pathophysiology of the disease, preoperative optimisation, anaesthetic considerations, role of advanced monitoring and regional anaesthesia and current literature on the management of patients with MMA.