Changes in Energy Expenditure Determined by Indirect Calorimetry in Severe Burn Patients During the Acute Phase

Abstract

Background: Severe burn injuries are a major health problem globally. A profound and prolonged hypermetabolic response develops in severe burn injuries and it is crucial to monitor the patients' energy requirements in order to meet them adequately. The aim of the present study was to examine the energy changes during the acute phase using the indirect calorimetry (IC) method in severe burn patients.

Methods: The study included 15 severe burn patients. Patients with FiO₂ >60%, tube thoracostomy, closed underwater drain (CUWD) and air leakage were excluded from the study. Patients' demographic data, burn percentages, burn types, duration of stay in intensive care, mortality and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were recorded. Indirect calorimeter measurements were taken once from the patients upon their first arrival and during the following four weeks. Resting energy expenditure (REE), basal metabolic rate (BMR), oxygen consumption (VO₂), carbon dioxide production (VCO₂), body temperatures, presence of sepsis, Sequential Organ Failure Assessment (SOFA) and Modified Nutrition Risk in Critically Ill (mNUTRIC) scores were recorded. The data were analysed using SPSS 24 and p-values <0.05 were considered statistically significant.

Results: In the study, 13 (86.67%) of the patients were male. Patients' mean age was 45.27±18.16 years, and mean BMI 25.99±4.22 kg/m². Five patients (33.33%) had chronic diseases. The average burn percentage was 45%, with 7 (46.67%) patients having a burn percentage of ≤40%, while 8 (53.33%) had a burn percentage of >40%. A total of 14 (93.33%) had flame burns; 3 (20.00%) patients deceased, and 12 (80.00%) were discharged. The mean APACHE II score was 11.53±6.83. The measured mean values of REE, VO₂, VCO₂ and fever were seen to be the highest in the first week after admission and decreases were observed in the subsequent weeks. SOFA score averages were the highest at admission, and decreased in the following weeks.

Conclusion: Severe burn patients were observed to go through the hypermetabolic process in the acute phase and their energy requirements were high particularly in the first week. It was concluded that regular IC monitoring can be beneficial to fully meet the energy requirements of severe burn patients due to the prolonged hypermetabolic process.

Keywords: adult burn patients; basal metabolic rate; indirect calorimetry; resting energy expenditure; severe burn patient.