Glutamine Enriched Total Parenteral Feeding and Proline Metabolism in Severely Burned Patients.
Glutamine Enriched Total Parenteral Feeding and Proline Metabolism in Severely Burned Patients.
Proline is a non-essential amino acid that helps with collagen formation. Collagen is one of the main ingredients of skin, bone, tendons, and connective tissue. It is thought that proline becomes depleted in burn patients because it is being used in greater than normal quantities to help the injured skin and connective tissue heal. If this is true, then the body must look for alternate energy sources as proline becomes depleted.
This study aims to evaluate 1)the metabolic kinetics of the amino acids proline, glutamate, and ornithine and 2) the effects of glutamine supplemented total parenteral nutrition (TPN) on the metabolism of these amino acids.
Proline is a nutritionally dispensable (non-essential) amino acid. Its synthesis and catabolism is via the pathway of ornithine and glutamate. The latter two amino acids serve as immediate precursors for proline, as well as metabolites. Ornithine is one of the intermediates for urea cycle. Glutamate is metabolically connected to tricarboxylic acid (TCA) cycle, the major cycle for energy production.
It is hypothesized that the significantly increased rates of net nitrogen loss and energy "production", as the consequence of the accelerated activities of both the urea and TCA cycles in burn injury "drain" both ornithine and glutamate, thus depleting tissues of the availability of proline. Hence, the de novo synthesis of proline is likely to be affected by the reduced availability of its major precursors: glutamate and ornithine. We further propose that increased supply of glutamine would increase the de novo synthesis of proline and / or spare the loss of proline via its metabolite glutamate. Hence, glutamine will be beneficial to the overall nutritional status of the burn patients.
Inclusion Criteria:
Burn patients being treated at MGH Burn Unit with one or more of the following criteria: 1) >=5% TBSA; 2) inhalation injury; or 3) resting energy expenditure (REE) of >15% of the predicted Basal Metabolic Rate using the Harris-Benedict equation.
Must be receiving total parenteral nutrition in the course of their treatment.
Exclusion Criteria:
Patients with thyroid disease. Patients who are not hemodynamically stable or show unstable vital signs Patients at the stage of major organ failure, e.g. renal and/or liver failure.