Substrate composition and sepsis. Effects on immunity

T. J. Mullin and J. R. Kirkpatrick

A randomized prospective study was performed to determine the effects of substrate composition on immunity in septic malnourished patients. A balanced substrate formula was administered to 11 patients with sepsis and 11 nonseptic patients. This provided 40 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 50:1. A 25% dextrose and 4.25% protein solution that provided 50 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 150:1 was provided to ten patients with sepsis and 11 without. Skin test conversion rates were not affected by substrate composition; however, the absolute lymphocyte count was significantly improved in septic patients who achieved positive nitrogen balance, regardless of the nutritional support regimen used. These findings suggest that substrate composition per se has no effect on immunologic responsiveness.