Lipid infusion increases oxygen consumption similarly in septic and nonseptic patients

This investigation compared the metabolic effects of lipid infusion in five septic and five nonseptic patients. Oxygen consumption was determined by indirect calorimetry over 1 h of rest and during 2 h when Intralipid (20%) was infused [166 mL/h; 23 kJ/min (5.5 kcal/min)]. Septic patients had a resting metabolic rate 17% higher than that of their nonseptic control subjects and a significant (P less than 0.05) rise (13%) in oxygen uptake was measured in both groups of subjects during the 2-h infusion of lipid. Preinfusion respiratory quotient (RQ) was 7% higher in the septic patients (P less than 0.05), and during the infusion period RQ decreased similarly (approximately 6%; P less than 0.05) in both groups. Plasma catecholamines were elevated in the septic patients preinfusion and the concentrations remained unaltered during the infusion. Norepinephrine rose significantly in the nonseptic group with the lipid infusion. The results show that sepsis has little or no influence on the characteristic rise in metabolic rate that occurs with intravenous lipid.