PubMed1980
Total exchangeable potassium (Ke) measurements were done on 13 patients who received total parenteral nutrition (TPN) at 25% dextrose and 2.5% amino acids (AA) (a hypertonic dextrose solution) by central vein, and 12 patients who received TPN as 10% dextrose, 10% fat emulsion (Intralipid), and 2.5% AA with lipid supplying about 60% of the nonprotein calories. There were 13 patients with benign diseases, three with carcinoma resected for cure, four with sepsis, three with severe burns, and two receiving chemotherapy for cancer. All but four of the septic and three of the burned patients had lost more than 10% of their normal body weight. A tracer dose of 150 to 300 microCi of K42 was injected intravenously during the first few days of the TPN therapy and a 48-hour urine collection and 24-, 36-, and 48-hour urine spot samples were obtained. Measurement of Ke was repeated after 7, 14, or 21 days of TPN therapy. Calories per kilogram per day, delta K per day, and percent delta K per day were determined for each patient and the data entered into a Textronics graphics computer for selection of curves of best fit. Similar curves of calories per kilogram per day versus delta K per day were obtained for the central and peripheral TPN groups. Intercepts where the body cell mass was maintained were at 32 calories/kg/day for the central TPN group and 34 calories/kd/day for the peripheral TPN group. Patients in both groups received a minimum of 0.6 gm protein/kg/day and the majority received from 0.8 to 1.2 gm protein/kg/day. Protein intake correlated with delta K per kilogram per day in the central but not the peripheral TPN group. We conclude that in nonseptic malnourished patients, an Intralipid calorie is as efficient as a dextrose calorie and that delta K is related to caloric rather than protein intake. None of the septic or burned patients maintained his body cell mass. However, they all received less than 30 calories/kg/day for a number of reasons.