Study of Glutamate and Glutamine Metabolism in Burn Patients Receiving Enteral or Parenteral Nutrition

Study of Glutamate and Glutamine Metabolism in Burn Patients Receiving Enteral or Parenteral Nutrition

Study of Glutamate and Glutamine Metabolism in Burn Patients Receiving Enteral or Parenteral Nutrition

State of Mass. tightened regulations for making intravenous solutions for research subjects. Study was withdrawn and no participants were enrolled.

The purpose of the study is to understand how the body uses amino acids in burned patients during the time they cannot eat normally. Amino acids occur naturally in the body and the food we eat. The body combines amino acids to make protein. It uses the proteins to do things such as heal wounds, fight infection, and provide energy. We are studying two ways of receiving nutrition: through a vein or through a tube. We are also studying two different types of food: with or without glutamine. The results of this study will be used to determine the best type and way to supply nutrients during a severe burn injury. We hope to learn how to help the body use nutrients more efficiently to better repair wounded tissues and recover earlier from injury.

We hypothesize that: Burn patients will experience an increased conversion of glutamine to glutamate and a decreased conversion of glutamate to glutamine as compared to healthy subjects. The net direction is from glutamine to glutamate in burn patients and would render glutamine as a conditionally essential amino acid. Because of the limited ability of liver to oxidize glutamate, it is possible that large doses of glutamine may cause increased gluconeogenesis in burn patients, thus aggravating the glucose homeostasis secondary to insulin resistance. Enterally and parenterally fed glutamine and glutamate have different metabolic fate in the splanchnic bed and peripheral regions, therefore the doses should be tailored according to the route of administration. This study, using stable isotope tracers, aims to track the metabolic fate of glutamine and glutamate in body with the goal of enhancing nutritional efficiency.

glutamine metabolic kinetics, glutamate metabolic kinetics, enteral nutrition, parenteral nutrition, burn injury, stable isotopes

Patient in each group will continue on the same diet for > 3 days before we conduct stable isotope tracer measurements.

This is a nutritional study. The primary outcome is to measure the protein kinetics for metabolism of the amino acid, glutamate and glutamine. Fate will be determine from measurements of subject blood and air samples.

Inclusion Criteria: One or more of the following: 5% Total Body Surface Area Thermal Burn Inhalation Injury Resting Energy Expenditure of >15% of the predicted Basal Metabolic Rate Using Harris-Benedict. Receiving Enteral or Parental Nutritional Support Exclusion Criteria: Pre-existing: Thyroid disease Congestive Heart Failure (Ejection fraction <20%) Malignancy currently under treatment Medical conditions requiring glucocorticoid treatment Decision not to treat because of severity of injury Presence of Anoxic brain injury with no expectation for recovery Self-Inflicted thermal injury Ileus, gut paralysis, or facial injuries No NG or OG tube as part of their clinical care

Sheridan RL, Prelack K, Yu YM, Lydon M, Petras L, Young VR, Tompkins RG. Short-term enteral glutamine does not enhance protein accretion in burned children: a stable isotope study. Surgery. 2004 Jun;135(6):671-8. doi: 10.1016/j.surg.2003.11.014.

Young VR, Ajami AM. Glutamine: the emperor or his clothes? J Nutr. 2001 Sep;131(9 Suppl):2449S-59S; discussion 2486S-7S. doi: 10.1093/jn/131.9.2449S.

Herndon DN, Tompkins RG. Support of the metabolic response to burn injury. Lancet. 2004 Jun 5;363(9424):1895-902. doi: 10.1016/S0140-6736(04)16360-5.