Reducing parenteral energy and protein intake improves metabolic homeostasis after bone marrow transplantation

The purpose of this prospective study was to compare the metabolic effects of reducing parenteral energy and protein intake in bone-marrow-transplant (BMT) patients from 150% (hi-TPN group) to 100% (lo-TPN group) basal energy expenditure. Cytotoxic therapy was given on days 1-5, BMT on day 6, and TPN beginning on days 6 or 7. The lo-TPN group exhibited higher serum albumin (38 ± 0.4 vs 32 ± 0.4 g/L, P < 0.01) but similar nitrogen balance (-83 ± 8 vs -86 ± 8 mg · kg^-1 · d^-1 P > 0.05). Serum Na⁺ remained > 134 ± 1 mmol/ L in the lo-TPN group but fell to 127 ± 1 mmol/L in the hiTPN group (P < 0.001) despite similar Na⁺ intakes and balances. Serum K⁺ remained < 4.4 ± 0.2 mmol/L in the lo-TPN group but rose to 5.1 ± 0.1 mmol/L in the hi-TPN group (P < 0.01) despite similar K⁺ intakes and balances. Delivering TPN at lower-than-normal rates after BMT appears to minimize Na⁺ and K⁺ disturbances and improve serum albumin concentrations without having any adverse effect on nitrogen balance.