The Metabolic Response to Burns

Since Cuthbertson first published his important investigations, the metabolic response to trauma has been the subject of continuous study in many disciplines of medicine (1-8). An impressive body of knowledge has been accumulated with respect to changes in plasma electrolyte concentrations, urinary electrolyte excretion, body composition, and adrenocortical activity. There is general agreement that injury is accompanied by an increased excretion of nonprotein nitrogenous products, but the importance of this phenomenon, its interpretation in terms of body economy, and its therapeutic implications remain the subject of controversy (4, 5, 7). On the basis of the nitrogen-sulfur and nitrogen-phosphorus ratios in the urine of rats with fractures, Cuthbertson concluded in his earlier studies that the increased excretion of nitrogen after fractures results chiefly from muscle catabolism (1). Howard and Mason, on the other hand, were unable to correlate nitrogen balance with that of potassium or phosphorus in postoperative patients (8). In burned rats, Braasch, Bell, and Levenson noted only transiently increased excretion of potassium and phosphorus while nitrogen excretion remained high for longer periods of time (9). Cope, Nathanson, Rourke, and Wilson (10) and Moore and Ball (7) recorded early negative nitrogen and positive potassium balance in burned patients. In the present study, the balances of nitrogen, calcium, phosphorus, magnesium, potassium, sodium, and chloride were measured in burned patients for long periods of time. Information was sought about 1 ) the relative rates of mineral losses, and 2) changes in body composition.