Accordingly, we and others 9 - 13 have developed intravenous solutions containing mixtures of essential and nonessential amino acids devoid of leucine, isoleucine, and valine for this purpose. Saudubray et al 6 have calculated that the anabolic effect of a gain in body weight of as little as 50 g would lead to an incorporation of sufficient leucine (1000 mg) into protein to decrease the plasma concentration by 3000 µmol/L (40 mg/dL). They also require expertise, particularly in their application to very young infants, that may not always be available.Ī reasonable alternative approach is to harness the forces of anabolism and protein synthesis by providing energy and a mixture of amino acids lacking leucine, isoleucine, and valine, such that these accumulated amino acids are laid down into protein, reducing levels in extracellular fluid and reversing toxic effects. Furthermore, extracorporeal techniques have complication risks, such as infection and intestinal obstruction, 8 and increase catabolism, which is counterproductive. 6 Hemodialysis 7 is doubtless more efficient, but the possible necessity of hemodialysis for every respiratory infection during the first few years of life is a daunting prospect. Direct measurements have indicated the removal of small quantities of amino acids by these methods. 1 - 5 Exchange transfusions have been used but are not recommended. The objective of therapy is the prompt reduction of the concentrations of the branched-chain amino acids. As concentrations of leucine and the other branched-chain amino acids rise, ataxia and lethargy may progress rapidly to coma, which may lead to apnea requiring assisted ventilation or irreversible cerebral edema. These crises occur during the initial neonatal episode, during which most patients receive their diagnosis, and later following dietary indiscretion, surgery, injury, or, most often, intercurrent infection. TREATMENT of the episode of acute metabolic decompensation in maple syrup urine disease (MSUD) is a medical emergency. Valine supplementation was also useful.Ĭonclusions The acute crisis of metabolic imbalance in maple syrup urine disease may be effectively treated by the continuous intragastric drip of solutions of amino acids devoid of leucine along with provision of water and calories intravenously. This led to greater and earlier supplementation with isoleucine. Concentrations of isoleucine fell to levels that made this amino acid limiting for protein synthesis and hence therapeutic effect. Rates of fall were comparable to those obtained with intravenous therapy.

Results In each instance, a progressive fall in leucine concentration was obtained. Clinical status closely mirrored the concentration of leucine. Main Outcome Measures Effects on the concentrations of leucine and the other branched-chain amino acids. Four different mixtures were used and a fifth was designed on the basis of this experience. Intervention Studies were carried out for 4 to 11 days, during which there was no intake of leucine. Data were collected during the management of 3 episodes of metabolic imbalance. Patients Two patients with maple syrup urine disease. They were designed to be used in the management of the acute crisis. Needs for water and calories were to be met intravenously. Objective To develop enteral mixtures suitable for administration by nasogastric drip in minimal volume.ĭesign Mixtures of amino acids were designed containing no leucine, isoleucine, or valine for administration by nasogastric drip.

However, these intravenous mixtures are not generally available. Experience with intravenous mixtures of amino acids indicates that this can be accomplished by the synthetic forces of protein synthesis. Shared Decision Making and Communicationīackground The acute crisis of metabolic decompensation in maple syrup urine disease is a potentially lethal medical emergency that requires reduction in concentrations of leucine and other branched-chain amino acids in plasma.Scientific Discovery and the Future of Medicine.Health Care Economics, Insurance, Payment.Clinical Implications of Basic Neuroscience.Challenges in Clinical Electrocardiography.

Maple syrup urine disease in adults