Similar metabolic responses to standardized total parenteral nutrition of septic and nonseptic critically ill patients

Background: Nutritional support is an important link between the response t o injury and recovery in critical illness. Objective: Our goal was to evaluate energy and substrate metabolism in sept ic and nonseptic critically ill patients in the resting state and during th e administration of standardized total parenteral nutrition. Design: This was a prospective, clinical cohort study of 25 consecutively a dmitted critically ill patients either with (n = 14) or without (n = 11) se psis who received total parenteral nutrition. Resting energy expenditure wa s measured on days 0, 2, and 7 by indirect calorimetry. Energy and substrat e balances were calculated on days 2 and 7. Results: Resting energy expenditure was not significantly different between septic and nonseptic patients on day 0 (2.65 +/- 0.49 and 2.36 +/- 0.56 kJ (.)min(-1.)m(-2), respectively). Energy balances were positive for both gro ups on days 2 (0.68 +/- 0.4 and 0.74 +/- 0.6 kJ(.)min(-1.)m(-2) respectivel y; NS) and 7 (0.65 +/- 0.3 and 0.78 +/- 0.5 kJ(.)min(-1.)m(-2) respectively ; NS). Substrate balances were not significantly different between groups o n days 0, 2, and 7. Resting energy expenditure on day 0 was negatively corr elated with the severity of illness in septic patients only (r = -0.58, P < 0.05). Conclusions: Metabolic changes were not significantly different between sep tic and nonseptic critically ill patients during the administration of stan dardized total parenteral nutrition. A disease-specific macronutrient compo sition of total parenteral nutrition formulas does not seem to be necessary in either septic or nonseptic critically ill patients.