Nitrogen requirements in severely injured patients

The body's nitrogen balance is influenced by protein and energy intake. Most of the body's nitrogen is used in synthesis of protein. When the breakdown of protein exceeds the synthesis of protein, a negative nitrogen balance occurs (a state of tissue wasting). After trauma there is a decrease in protein synthesis causing loss of protein and negative nitrogen balance. This study examines the influence of different levels of nitrogen intake on protein metabolism in 39 patients with severe injuries, burns or multiple long-bone fractures. The patients ranged in age range from 18 to 65. All patients were given fat and glucose energy sources intravenously; they were divided into five groups, each given a different amount of nitrogen, ranging from 0 to 0.3 grams per kilogram of body weight each day. Their daily and cumulative nitrogen balances were evaluated on the second, fourth and eighth days after injury. It was found that the daily nitrogen balance improved when patients were given up to 0.2 grams per kilogram; beyond that level there was no improvement in nitrogen balance. Retention of nitrogen decreased with an increase in the supply of nitrogen and with time after injury. It is suggested that severely injured patients receive a nitrogen supply of 0.2 grams per kilogram of body weight for the first week following injury. (Consumer Summary produced by Reliance Medical Information, Inc.)