Metabolism of fat emulsions by thermally injured patients

The lipolytic capacity of patients with severe and moderate thermal injury was assessed in vivo by determining the rate of clearance of chylomicrons. Twelve patients, two women and ten men, age 34 +/- 12 years, had burns varying from 28% to 84% of total burn surface area (TBSA). Seven patients had an average burn size of 63% TBSA. They were hypocholesterolemic and normotriglyceridemic during parenteral alimentation that excluded fat emulsion. But when Lyposil was infused intravenously (150 mg/kg/hr for a period of eight hrs), plasma triglyceride (TG) levels increased. Most of the triglyceride was in the form of chylomicrons, which had a prolonged residence time in plasma. Patients with moderate thermal injury (mean % TBSA 38% +/- 9%) had normal TG levels before fat infusion. When Liposyl was infused intraduodenally (170 mg/kg/hr), the plasma TG levels remained normal and the chylomicron half-life was very short. These observations suggest that patients with severe thermal injury may have reduced lipolytic capacity, especially during parenteral administration of fat emulsion.