Differential effects of three enteral dietary regimens on selected outcome variables in burn patients. Improved clinical status and length of care with low-fat nutrition support in burn patients.
A modular tube feeding recipe (MTF) was designed to meet the unique nutritional needs of burn patients, applying principles previously documented in our burned guinea pig model. MTF, a high-protein, low-fat, linoleic acid-restricted formulation is enriched with omega-3 fatty acids, arginine, cysteine, histidine, vitamin A, zinc, and ascorbic acid. Fifty patients, 3 to 76 years of age with burns ranging from 10 to 89% total body surface area were prospectively randomized into three groups which blindly compared MTF to two enteral regimens widely utilized in the nutritional support of burns. Age, percent total and third-degree burn, resting energy expenditure, and calorie and protein intake were similar in all groups. Data analysis demonstrated significant superiority of MTF in the reduction of wound infection (p less than 0.03) and length of stay/percent burn (p less than 0.02). MTF was also associated with a decreased incidence of diarrhea, improved glucose tolerance, lower serum triglycerides, reduced total number of infectious episodes and trends toward improved preservation of muscle mass, although statistical significance was not achieved. Seventy percent of deaths occurred in the group supported with an inherently large dose of fat and linoleic acid. Combining these observations, it is believed that MTF is effective in modulating an improved response to burn injury. The optimal amount and type of fat in the nutrition support of burned patients have not been determined. The aim of this study was to test low-fat nutritional solutions, with or without fish oil, on protein metabolism, morbidity, and length of care in severely burned adults.
                In a prospective randomized clinical trial, 43 patients were assigned to one of the following groups: control (35% fat), low-fat solution (ie, 15% of total calories as fat), low-fat with fish oil, given for 30 days. Nitrogen balance, urinary 3-methylhistidine excretion, urinary cortisol, and clinical status were measured daily. Corticosteroid-binding globulin and total and free serum cortisol were measured every 3 days.
                Compared with controls, patients on low-fat support had fewer cases of pneumonia: 3/24 vs 7/13 (p = .02), better respiratory and nutrition status, and shorter time to healing: 1.2 vs 1.8 days/% burned area (p = 0.01). There was no difference in nitrogen balance between groups, and 3-methylhistidine excretion was higher and serum free cortisol was lower in log-fat--fed patients than in controls. There was no difference between the two low-fat groups in any of the parameters measured.
                This study showed that low-fat nutrition support decreases infectious morbidity and shortens length of stay in burn patients. Fish oil does not seem to add clinical benefit to low-fat solutions. In addition, this study provides the first evidence that nutrition intervention modulates cortisol-binding globulin and the concentration of free circulating cortisol after a severe stress.