Body Composition Changes in Severely Burned Children During ICU Hospitalization.

OBJECTIVES: Prolonged hospitalization due to burn injury results in physical inactivity and muscle weakness. However, how these changes are distributed among body parts is unknown. The aim of this study was to evaluate the degree of body composition changes in different anatomical regions during ICU hospitalization. DESIGN: Retrospective chart review. SETTING: Children's burn hospital. PATIENTS: Twenty-four severely burned children admitted to our institution between 2000 and 2015. INTERVENTIONS: All patients underwent a dual-energy x-ray absorptiometry within 2 weeks after injury and 2 weeks before discharge to determine body composition changes. No subject underwent anabolic intervention. We analyzed changes of bone mineral content, bone mineral density, total fat mass, total mass, and total lean mass of the entire body and specifically analyzed the changes between the upper and lower limbs. MEASUREMENTS AND MAIN RESULTS: In the 24 patients, age was 10 ± 5 years, total body surface area burned was 59% ± 17%, time between dual-energy x-ray absorptiometries was 34 ± 21 days, and length of stay was 39 ± 24 days. We found a significant (p < 0.001) average loss of 3% of lean mass in the whole body; this loss was significantly greater (p < 0.001) in the upper extremities (17%) than in the lower extremities (7%). We also observed a remodeling of the fat compartments, with a significant whole-body increase in fat mass (p < 0.001) that was greater in the truncal region (p < 0.0001) and in the lower limbs (p < 0.05). CONCLUSIONS: ICU hospitalization is associated with greater lean mass loss in the upper limbs of burned children. Mobilization programs should include early mobilization of upper limbs to restore upper extremity function.

Upper airway mucus deposition in lung tissue of burn trauma victims.

Previous study in an ovine model of smoke inhalation and burn (S + B) injury has shown distal migration of upper airway mucus. This study examines the localization of an upper airway gland specific mucus, mucin 5B (MUC5B) in lung autopsy tissues of burn-only injury and in victims of S + B injury. We hypothesize that victims with S + B injury would exhibit increased distal migration of MUC5B than that seen in victims of burn-only injury. Autopsy lung tissue from victims of burn injury alone (n = 38) and combined S + B injury (n = 22) were immunostained for MUC5B. No normal lung tissues were included in the study. Semiquantitative analysis of the extent of MUC5B in bronchioles and parenchyma was performed on masked slides. Irrespective of injury conditions, all victims showed MUC5B in bronchioles. Mucin 5B was seen in the parenchyma except in two burn victims. No statistically significant difference was seen in the mean bronchiolar and parenchyma MUC5B scores between S + B and burn-only victims (P > 0.05). No strong statistical correlation of MUC5B scores with days postinjury or to the number of ventilatory days was evident. The percentage of pneumonia, identified histologically, was also similar between study groups. This study did not confirm our results in an ovine model of S + B injury. In contrast, virtually all pediatric burn victims, regardless of concomitant inhalation injury, showed MUC5B in their bronchioles and parenchyma. Increased mucus synthesis and/or impaired mucociliary function may contribute to the pulmonary pathophysiology associated with burn injury.

Sex differences in the long-term outcome after a severe thermal injury.

We have recently shown that during the acute phase, postburn female pediatric burn patients had significantly increased levels of anabolic hormones with an associated decreased hypermetabolism leading to a significant shorter intensive care unit stay compared with male patients. The aim of the present study was to determine possible differences between girls and boys in body composition, hypermetabolism, and hormone pattern in the long term. Sixty-two children (1-16 years old) who sustained a severe thermal injury (>or=40% total body surface area) were included into the study. Patients were further divided into girls (n = 22) and boys (n = 40). Patient demographics, nutritional support, and mortality were noted. Resting energy expenditure (REE) was measured by indirect calorimetry, body composition by dual-energy x-ray absorptiometry (Hologic Inc, Waltham, Mass) at discharge, 3, 6, 9, 12, 18, and 24 months after burn. In addition, blood was drawn at the same time points, and serum hormones were measured. There were no significant differences between girls and boys for demographics, nutritional intake, or concomitant injuries. Predicted REE was significantly decreased in girls at discharge, 6, 12, and 18 months postburn (P < 0.05). Dual-energy x-ray absorptiometry scan showed that girls had improved change in bone mineral content and percent fat compared with boys (P < 0.05). There were no differences in changes in height, body weight, lean body mass, and total fat between groups. Girls had significantly higher levels of insulinlike growth factor 1, insulinlike growth factor binding protein 3, free thyroxine index, T4, and insulin when compared with boys (P < 0.05). No differences were found for T3 uptake, osteocalcin, cortisol, growth hormone, and parathyroid hormone (PTH) between groups. Data indicate that girls have a reduced REE associated with changes in bone content and endogenous anabolic hormones.

Endogenous anabolic hormones and hypermetabolism: effect of trauma and gender differences.

OBJECTIVE: Protein degradation, negative nitrogen balance and compromised structure of essential organs have been associated with resistance and decreased production of anabolic hormones. In turn, increased levels of anabolic hormones are associated with improved survival. The aims of the present study were to determine the pattern of anabolic hormones, resting energy expenditure and cytokines in severely thermally injured pediatric patients and to compare these parameters in female and male patients. METHODS: Sixty-five children (1 to 16 years of age) sustaining a severe thermal injury (> or =40% TBSA) were included into the study. Patients were further divided into females (n = 22) and males (n = 43). Patient demographics, nutritional support, incidence of sepsis, inhalation injury, and mortality were noted. Resting energy expenditure was measured during hospital course by indirect calorimetry. Blood was drawn 0, 10, 20, and 40 days postburn and serum insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-1 and -3 (IGFBP-1, and -3), growth hormone, insulin, and cytokines were measured. RESULTS: There were no significant differences between females and males for demographics, nutritional intake, or concomitant injuries. In both groups, endogenous anabolic agents were drastically decreased by 3- to 5-fold up to 40 days posttrauma. Females had significantly higher levels of IGF-I, IGFBP-3, growth hormone, and insulin when compared with males, P < 0.05. Increased levels of anabolic hormones were associated with decreased stay on the ICU (females 36 +/- 22 days versus males 53+/- 39 days), decreased serum IL-1beta and TNF-alpha as well as resting energy expenditure, P < 0.05. CONCLUSION: Data indicate that despite adequate nutritional support, severe thermal injury leads to decreased anabolic hormones over a prolonged period of time. Female patients had significantly increased levels of anabolic hormones, which are associated with decreased proinflammatory mediators and hypermetabolism, leading to a significant shorter ICU stay compared with male patients.