Nonprotein Calorie-to-Nitrogen Ratio at Flow Phase in Patients With Major Burn Injuries

Abstract

ABSTRACT OBJECTIVES: Protein is the only nutrient that provides nitrogen, and nitrogen has important roles in metabolism, wound healing, and recovery of burns. During burn injuries, metabolic states are similar to other higher metabolic stress clinical conditions and are classified as the ebb (early), flow (second), or anabolic (third) phase, depending on time postinjury, with the early phase from injury to 48 hours, the second phase from 48 to 72 hours, and the third phase up to 1 year. In burn patients, the flow phase is crucial because nutrient substrates are utilized, requiring patients to have a high calorie and high protein diet along with standard micronutrients supplements, with recommendations defining a 100:1 to 150:1 calorie-to-nitrogen ratio for patients with major burns. Most patients require additional protein if they have open wounds. Here, we evaluated effects and outcomes of nonprotein calorie-to-nitrogen ratio in high-calorie and high-protein diets in patients with major burns seen at our center. MATERIALS AND METHODS: Our retrospective study included 54 male and female adult patients (18-60 years of age) with 20% to 60% total burn surface area burn injury who had reached our hospital within 12 hours of injury from 2017 to 2021. After primary clinical management and resuscitation, all patients received nutritional care, with monitoring of nonprotein calorie-to-nitrogen ratio. Outcome measures included length of hospital stay, recovery of wounds, and final outcome. RESULTS: Nonprotein calorie-to-nitrogen ratio was maintained at 93:1 during the flow phase of metabolism in all patients. Maintenance of this ratio was significantly correlated with positive measures of wound healing, length of stay, and final outcome. CONCLUSIONS: The nonprotein calorie-to-nitrogen ratio has important roles in the early phase of higher metabolic stress conditions in patients with burns. Maintaining a ratio of at least 100:1 ratio can result in better outcomes for patients.