Amino acid clearance during acute metabolic decompensation in maple syrup urine disease treated with continuous venovenous hemodialysis with filtration

Objective: Assessment of amino acid clearances by continuous venovenous hemodialysis with filtration in treatment of a metabolic decompensation in acute maple syrup urine disease. Design: Single patient assessment. Setting: Pediatric intensive care unit. Patients: A 10-yr-old male with known maple syrup urine disease (branched chain alpha-ketoacid dehydrogenase deficiency) with metabolic decompensation due to an acute viral illness, characterized by altered mental status, progressive obtundation, and severe acidosis. Interventions: Continuous venovenous hemodialysis with filtration. Measurements and Main Results: Continuous venovenous hemodialysis with filtration was instituted with both filtration (500 mL/m2/hr) and dialysis (1000 mL/m2/hr) utilized, allowing rapid correction of systemic ketoacidosis while providing amino acid clearance. Amino acid clearance was measured at initiation and at 24 hrs into therapy. The procedure was well tolerated, with near normal mental status within 12 hrs and resumption of enteral feedings. During the 24-hr period of continuous venovenous hemodialysis with filtration, serum leucine levels fell from 2352 to 381 μmoles/L, isoleucine fell from 626 to 164, and valine fell from 1117 to 228. Leucine, isoleucine, and valine clearance rates averaged 13.1, 12.8, and 13.2 mL/min, respectively, and were constant during the 24 hrs of treatment. Clearance of other amino acids during this period did not vary significantly between cationic, anionic, neutral, or hydrophobic amino acids. Conclusions: Continuous venovenous hemodialysis with filtration provides an effective therapeutic alternative to intermittent hemodialysis during acute metabolic decompensation in maple syrup urine disease.