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The purpose of this study was to evaluate whether burn survivors have lower adherence compared to non-burned control individuals during a 6-month community-based exercise program. In burn survivors, we sought to answer if there was a relation between the size of the burn injury and dropout frequency. Fifty-two burn survivors and 15 non-burned controls (n = 67) were recruited for a 6-month community-based (ie, non-supervised), progressive, exercise training program. During the exercise program, 27% (ie, 4 of the 15 enrolled) of the non-burned individuals dropped out of the study, while 37% (ie, 19 of the 52) of the burn survivors dropped out from the study. There was no difference in the percentage of individuals who dropped out between groups (P =.552). There was no difference in size of the burn injury, expressed as percent body surface area burned (%BSA) between the burn survivors that dropped out versus those who completed the exercise regimen (P =.951). We did not observe a relation between %BSA burned and dropouts (log odds = −0.15–0.01(%BSA), B = −0.01, SE = 0.015, P =.541). There was no effect of %BSA burned on the probability of dropout [Exp (B) = 0.991, 95% CI (0.961, 1.020)] and there were no differences in the percentage of individuals who dropped out of the study based on %BSA burned (χ 2(1) = 0.44, P =.51). These data demonstrate that burn survivors have similar exercise adherence relative to a non-burned group and the extent of a burn injury does not affect exercise program adherence. [ABSTRACT FROM AUTHOR]

Sub‐acute (e.g., inhalation injury) and/or acute insults sustained during a severe burn injury impairs pulmonary function. However, previous work has not fully characterized pulmonary function in adults with well‐healed burn injuries decades after an injury. Therefore, we tested the hypothesis that adults with well‐healed burn injuries have lower pulmonary function years after recovery. Our cohort of adults with well‐healed burn‐injuries (n = 41) had a lower forced expiratory volume in one second (Burn: 93 ± 16 vs. Control: 103 ± 10%predicted, mean ± SD; d = 0.60, p = 0.04), lower maximal voluntary ventilation (Burn: 84 [71–97] vs. Control: 105 [94–122] %predicted, median [IQR]; d = 0.84, p < 0.01), and a higher specific airway resistance (Burn: 235 ± 80 vs. Control: 179 ± 40%predicted, mean ± SD; d = 0.66, p = 0.02) than non‐burned control participants (n = 12). No variables were meaningfully influenced by having a previous inhalation injury (d ≤ 0.44, p ≥ 0.19; 13 of 41 had an inhalation injury), the size of the body surface area burned (R2 ≤ 0.06, p ≥ 0.15; range of 15%–88% body surface area burned), or the time since the burn injury (R2 ≤ 0.04, p ≥ 0.22; range of 2–50 years post‐injury). These data suggest that adults with well‐healed burn injuries have lower pulmonary function decades after injury. Therefore, future research should examine rehabilitation strategies that could improve pulmonary function among adults with well‐healed burn injuries. [ABSTRACT FROM AUTHOR]

Vast improvements in the survival rates following burn injuries has led to a greater number of patients living with a wide range of long-term impairments, activity limitations, and participation constraints. Therefore, long-term care is critical in this clinical population and necessitates appropriate rehabilitation strategies to maximize an individual's overall health. The purpose of this study was to test the hypothesis that the extent to which outcomes within the International Classification of Functioning, Disability, and Health (ICF) framework are improved following 6 months of unsupervised exercise training is influenced by the severity of a burn injury (i.e., percent body surface area injured). Outcome variables representing the dimensions of the ICF, body functions & structure, activity, and participation, were collected pre- and post- 6 months of exercise training in three groups of participants: non-injured control subjects (N = 11), subjects with moderate-level well-healed burn injuries (N = 13, 26 ± 6% body surface area burned), and subjects with high-level well-healed burn injuries (N = 20, 58 ± 15% body surface area burned). Exercise training improved lower extremity strength (changes in peak torque/kg body mass at 90 degrees/sec flexion: 30 ± 5% and extension: 36 ± 4%, p < 0.05) and functional activities (changes in sit to stand: -9 ± 4% and ascend stairs: -4 ± 1%; p < 0.05) in all groups. For outcome variables representing ICF levels of body functions & structure and activity, there were no differences at baseline or improvements made between the groups after training. That said, with the exception of the domain of functional activity (reported 17 ± 34% improvement in the high-level burn cohort, p < 0.05), no changes were revealed in the participation level of ICF indexed by health-related quality of life questionnaires. These findings support the utilization of a 6-month unsupervised exercise training program in the long-term rehabilitation of individuals with burn injuries; that is, improvements in body functions & structure and activity can be achieved with an exercise regimen regardless of the severity of burn injury. [ABSTRACT FROM AUTHOR]

The U.S. Army's Standards of Medical Fitness (AR 40-501) states: "Prior burn injury (to include donor sites) involving a total body surface area of 40% or more does not meet the standard." However, the standard does not account for the interactive effect of burn injury size and air temperature on exercise thermoregulation. Purpose: To evaluate whether the detrimental effect of a simulated burn injury on exercise thermoregulation is dependent on air temperature. Methods: On eight occasions, nine males cycled for 60 min at a fixed metabolic heat production (6 W·kg−1) in air temperatures of 40°C or 25°C with simulated burn injuries of 0% (Control), 20%, 40%, or 60% of total body surface area (TBSA). Burn injuries were simulated by covering the skin with an absorbent, vapor-impermeable material to impede evaporation from the covered areas. Core temperature was measured in the gastrointestinal tract via telemetric pill. Results: In 40°C conditions, greater elevations in core temperature were observed with 40% and 60% TBSA simulated burn injuries versus Control (P < 0.01). However, at 25°C, core temperature responses were not different versus Control with 20%, 40%, and 60% TBSA simulated injuries (P = 0.97). The elevation in core temperature at the end of exercise was greater in the 40°C environment with 20%, 40%, and 60% TBSA simulated burn injuries (P ≤ 0.04). Conclusions: Simulated burn injuries ≥20% TBSA exacerbate core temperature responses in hot, but not temperate, air temperatures. These findings suggest that the U.S. Army's standard for inclusion of burned soldiers is appropriate for hot conditions, but could lead to the needless discharge of soldiers who could safely perform their duties in cooler training/operational settings. [ABSTRACT FROM AUTHOR]

Although the severity of a burn injury is often associated with the percentage of total body surface area burned (%TBSA), the thermoregulatory consequences of a given %TBSA injury do not account for the interactive effects of body morphology and metabolic heat production (H prod). Purpose: Using a simulated burn injury model to mimic the detrimental effect of a 40% TBSA injury on whole-body evaporative heat dissipation, core temperature response to exercise in physiologically uncompensable conditions between morphologically disparate groups were examined at (i) an absolute H prod (W), and (ii) a mass-specific H prod (W·kg−1). Methods: Healthy, young, nonburned individuals of small (SM, n = 11) or large (LG, n = 11) body size cycled for 60 min at 500 W or 5.3 W·kg−1 of H prod in 39°C and 20% relative humidity conditions. A 40% burn injury was simulated by affixing a highly absorbent, vapor-impermeable material across the torso (20% TBSA), arms (10% TBSA), and legs (10% TBSA) to impede evaporative heat loss in those regions. Results: Although the elevation in core temperature was greater in SM compared with LG at an H prod of 500 W (SM, 1.69°C ± 0.26°C; LG, 1.05°C ± 0.26°C; P < 0.01), elevations in core temperature were not different at an H prod of 5.3 W·kg−1 between groups (SM, 0.99°C ± 0.32°C; LG, 1.05°C ± 0.26°C; P = 0.66). Conclusions: These data suggest that among individuals with a 40% TBSA burn injury, a smaller body size leads to exacerbated elevations in core temperature during physical activities eliciting the same absolute H prod (non–weight-bearing tasks) but not activities eliciting the same mass-specific H prod (weight-bearing tasks). [ABSTRACT FROM AUTHOR]

Long-term rehabilitative strategies are important for individuals with well-healed burn injuries. Such information is particularly critical because patients are routinely surviving severe burn injuries given medical advances in the acute care setting. The purpose of this study was to test the hypothesis that a 6-mo community-based exercise training program will increase maximal aerobic capacity (VO2max) in subjects with prior burn injuries, with the extent of that increase influenced by the severity of the burn injury (i.e., percent body surface area burned). Maximal aerobic capacity (indirect calorimetry) and skeletal muscle oxidative enzyme activity (biopsy of the vastus lateralis muscle) were measured pre- and postexercise training in noninjured control subjects (n = 11) and in individuals with well-healed burn injuries (n = 13, moderate body surface area burned; n = 20, high body surface area burned). Exercise training increased VO2max in all groups (control: 15 ± 5%; moderate body surface area: 11 ± 3%; high body surface area: 11 ± 2%; P < 0.05), though the magnitude of this improvement did not differ between groups (P = 0.7). Exercise training also increased the activity of the skeletal muscle oxidative enzymes citrate synthase (P < 0.05) and cytochrome c oxidase (P < 0.05), an effect that did not differ between groups (P = 0.2). These data suggest that 6 mo of progressive exercise training improves VO2max in individuals with burn injuries and that the magnitude of body surface area burned does not lessen this adaptive response. [ABSTRACT FROM AUTHOR]

Introduction Burned skin excision and subsequent grafting removes sweat glands, which impairs thermoregulation. Consequently, exercise prescribed for rehabilitation may expose individuals with burn injuries to a greater risk of hyperthermia, depending on exercise duration, intensity, and environmental temperature. Little is known regarding the risk of hyperthermia in adult burn survivors performing mild/moderate-intensity exercise under thermoneutral environmental conditions, i.e. conditions similar to the rehabilitation clinic and/or the gym. This project tested the hypothesis that burn survivors, across a wide range of percent total body surface area (%TBSA) burned, can participate in mild/moderate-intensity exercise in a thermoneutral environment without excessive elevations in core body temperature. Methods Twenty-eight well-healed burn survivors with low (23±5%TBSA; N=10), moderate (42±7%TBSA; N=9), and high (60±8%TBSA; N=9) sized burn injuries performed 60 minutes of cycle ergometry exercise (72±15 Watts, oxygen uptake rate of 1.25±0.21 L/min equivalent to 4.5±0.2 METs) in a 25°C and 23% relative humidity environment. Absolute gastrointestinal temperatures (Tcore) and changes in gastrointestinal temperatures (ΔTcore) were obtained at 15-minute increments throughout the exercise bout. A participant with an absolute Tcore of greater than 38.5°C, and/or a ΔTcore of >1.5°C, at any time point during the trial was categorized as being at risk for hyperthermia. Results Sixty minutes of exercise increased Tcore in all groups (Low: 0.72±0.21°C; Moderate: 0.42±0.22°C; High: 0.77±0.25°C, all P< 0.01 from pre-exercise baseline), resulting in similar absolute Tcore values of upon exercise termination (Low: 37.87±0.24°C; Moderate: 37.56±0.34°C; High: 37.76±0.47°C, P=0.19). Importantly, no participant was categorized as being at risk for hyperthermia, based upon the aforementioned criteria. Conclusions These data indicate that individuals with substantial %TBSA burned can exercise at a mild/moderate intensity for 60 minutes in thermoneutral environmental conditions without a risk of excessive elevations in body core temperature. [ABSTRACT FROM AUTHOR]

The U.S. Department of Defense's Medical Standards for Appointment, Enlistment, or Induction into the Military Services excludes personnel with burn injuries covering 18% or more of their body surface area (BSA). However, this requirement does not consider the metabolic heat loads associated with physical activities of different intensities that may influence a burn survivor's ability to perform his/her duties. Purpose: This study aimed to test the hypothesis that the elevation in internal body temperature during exercise in a hot environment is influenced by the combination of exercise intensity and BSA burned. Methods: Ten healthy participants (8 males, 2 females; 32 ± 9 yr; 75.3 ± 11.7 kg) completed eight exercise trials on a cycle ergometer, each with different combinations of metabolic heat productions (low, 4 W·kg−1; moderate, 6 W·kg−1) and simulated BSA burn in a hot environmental chamber (39.9°C ± 0.3°C, 20.1% ± 1.5% RH). Burns were simulated by covering 0%, 20%, 40%, or 60% of participants' BSA with a highly absorbent, vapor-impermeable material. Gastrointestinal temperature (T GI) was recorded, with the primary analysis being the increase in T GI after 60 min of exercise. Results: We identified an interaction effect for the increase in T GI (P < 0.01), suggesting T GI was influenced by both intensity and simulated burn BSA. Regardless of the percentage BSA burn simulated, the increase in T GI was similar across low-intensity trials (0.70°C ± 0.26°C, P > 0.11 for all). However, during moderate-intensity exercise, the increase in T GI was greater for the 60% (1.78°C ± 0.38°C, P < 0.01) and 40% BSA coverage trials (1.33°C ± 0.44°C, P = 0.04), relative to 0% (0.82°C ± 0.36°C). There were no differences in T GI responses between 0% and 20% trials. Conclusion: These data suggest that exercise intensity influences the relationship between burn injury size and thermoregulatory responses in a hot environment. [ABSTRACT FROM AUTHOR]