[Evaluation of protein catabolism in multi-injured patients]

The urinary excretion of nitrogen was calculated, using the daily urinary urea nitrogen output in 19 patients with multiple trauma. The patients were followed for at least two weeks in an intensive care unit. The urinary excretion for each patient was expressed as the average of 7 day periods and the differences were evaluated with the Student's test for paired samples. Protein catabolism (defined as a urinary nitrogen excretion higher than 0.250 g per kilo and per day) was found in 18 of 19 patients during the first week, and in 16 during the second week. Catabolism was still present in 8 of 11 the third week and in 3 of 6 the fourth week after the trauma. Nitrogen excretion remained at the same level for two weeks and decreased significantly afterwards. Protein catabolism was an important contribution to weight loss. The cumulative loss of lean body mass revealed approximately 70% of weight loss over four weeks. The role of factors involved in catabolism and a therapeutic approach are discussed.