Influence of Injury and Nutrition on Muscle Water and Electrolytes: Effect of Severe Injury, Burns and Sepsis

The changes in water and electrolyte metabolism associated with severe injury and sepsis are well recognized but changes in tissue content have seldom been available. This report combines the experience obtained from muscle biopsies of such patients performed in two centers; one located in Sweden and one in the U.S. Normal values for muscle water and electrolytes in each center are in close agreement. Needle biopsies of muscle were performed in 45 Swedish patients and 17 U.S. patients at intervals after injury or infection from the second to the thirtieth day. The patients' nutrition varied from brief periods of hypocaloric intake to prolonged high calorie parenteral nutrition with and without amino acids, as well as with and without fat. Prominent changes appeared during the first week and persisted up to 30 days regardless of the associated nutritional intake. These changes included an increased total muscle water, extracellular water, sodium and chloride and a decrease in muscle potassium and magnesium. This study demonstrates a simultaneous expansion of extracellular volume and a loss of intracellular components. This is in contrast to the experiences reported with less severe injury such as elective operation, where a more modest expansion of extracellular volume is seen and which is not associated with any loss of potassium or magnesium. The magnitude and persistence of these changes in muscle tissue deserve further study, both as to mechanism and implications for therapy.