Optimal energy and nitrogen intake for gastroenterological patients requiring intravenous nutrition
Smith, R.C.; Burkinshaw, L.; Hill, G.L.
Gastroenterology 82(3): 445-452
1982
ISSN/ISBN: 0016-5085 PMID: 6797863 Document Number: 190418
Gastroenterological surgical patients (30) requiring i.v. nutrition were randomized into 2 groups of 15 patients each. Group 1 received 40.3 .+-. 2.0 kcal .cntdot. kg-1 .cntdot. day-1 (7.0 mg glucose .cntdot. kg-1 .cntdot. min-1) and 0.27 .+-. 0.02 g N .cntdot. kg-1 day-1. Group 2 received 53.4 .+-. 6.8 kcal .cntdot. kg-1 .cntdot. day-1 (9.2 mg glucose .cntdot. kg-1 .cntdot. min-1) and 0.36 .+-. 0.05 g N .cntdot. kg-1 .cntdot. day-1. Total body fat, total body protein, total body water and total body minerals (K, Na, Cl, P, Ca) were measured before and after 14 days of treatment. Liver function was not adversely affected by the greater amount of i.v. nutrition. Group 1 patients were in energy balance but lost body protein (-0.5 kg), and body weight was maintained by retention of water. Group 2 patients had gains of fat (0.8 kg), protein (0.5 kg) and water (2.0 l). The energy value of the fat gain in this group was equivalent to the different amount of glucose given to these 2 groups of patients. The changes of water and minerals indicated that group 2 patients had gained normal lean tissue. When these results are related to previous studies in similar groups of patients, they confirm that glucose infusion of > 7 mg .cntdot. kg-1 .cntdot. min-1 results in net synthesis of body fat. They also suggest that a N intake of > 0.30 g N .cntdot. kg-1 .cntdot. day-1 is required to prevent net loss of body protein. This suggests that a calorie to N ratio of 135:1 or less is the optimal requirement for gastroenterological patients receiving i.v. nutrient solutions in which the energy source is glucose.