Energy requirements of parenterally fed bone marrow transplant recipients

To determine the energy intake (kcal/kg/day) necessary to maintain zero nitrogen balance (assuming adequate protein intake) during the first 30 days after transplant, we studied 91 bone marrow transplant recipients. Serial nitrogen balance and concomitant energy and protein intakes were determined prospectively on each patient. Eight-four (92%) of the patients (ages 4-49 yr) had sufficient data for evaluation. For each patient, a simple linear model (nitrogen balance vs energy intake) was used to determine the patient's predicted individual energy requirement during the first 30 posttransplant days (EReq30). Weighted least squares multiple regression was used to determine the effect on EReq30 of such variables as age and sex. Energy requirements were significantly (p less than 0.001) greater for children, males, and patients with acute graft-vs-host disease, and when the percent of the total energy intake given by the intravenous route was high. An equation that incorporated these variables was developed to predict the energy requirements for bone marrow transplant recipients during their first 30 posttransplant days. Although individual energy requirements vary, this equation is a useful guide for initial energy prescriptions.