Prevention of metabolic decompensation in an infant with mutase deficient methylmalonic aciduria undergoing cardiopulmonary bypass.

BACKGROUND Effects of circulatory arrest upon an inborn error of metabolism patient are unknown. METHODS A retrospective chart review was performed of outcome and biochemical parameters obtained during palliative cardiac surgery for a mutase-deficient methylmalonic aciduria patient with Ebstein's cardiac anomaly was performed. RESULTS The levels of ammonia, methylmalonic acid, free carnitine, and propionylcarnitine of the patient were improved. The patient survived surgery following institution of four metabolic treatment principles: 1) restriction of toxic substrate; 2) promotion of anabolism via administration of carbohydrate and lipid calories; 3) administration of detoxifying levocarnitine and sodium benzoate; and 4) cobalamin enzymatic co-factor administration. The patient died from post-operative dysrhythmia and was posthumously determined to have compound heterozygosity for mutations predicting severe, cobalamin non-responsive disease: c.322C>T/c.1233del3 (p.R108C/p.ΔI412). CONCLUSION Metabolic decompensation is preventable during cardiopulmonary bypass and cardioplegia using four principles of metabolic treatment.