Cardiorespiratory Capacity and Strength Remain Attenuated in Children with Severe Burn Injuries at Over 3 Years Postburn

The efficacy of therapeutic interventions on paediatric burn patients' height, weight, body composition, and muscle strength: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of therapeutic interventions on pediatric burn patients' height, weight, body composition, and muscle strength.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Web of Science up to March 2021. Eligible interventional studies reported metrics on the height, weight, body composition, or muscle strength of pediatric burn patients in a peer-reviewed journal. Meta-analyses were performed if ≥ 2 trials of clinical homogeneity reported on an outcome measure at the same time point post-burn.

RESULTS

Twenty-six interventional studies were identified, including twenty-two randomised controlled trials and four non-randomised trials. Most studies were conducted by a single institution. On average, the burn covered 45.3% ( ± 9.9) of the total body surface area. Three categories of interventions could be distinguished: rehabilitative exercise programs, pharmacologic agents, and nutrition support.

CONCLUSIONS

Each of the interventions had a positive effect on height, weight, body composition, or muscle strength. The decision to initiate an intervention should be made on a case-by-case basis following careful consideration of the benefits and risks. In future research, it is important to evaluate the heterogeneity of intervention effects and whether participation in an intervention allowed pediatric burn patients to reach the physical and functional status of healthy peers.

Inter-individual variability of aerobic capacity after rehabilitation exercise training in children with severe burn injury

INTRODUCTION

Severe burn trauma damages resting and exercise cardiac function that may affect long term cardiovascular health. The implementation of rehabilitation exercise training (RET) soon after hospital discharge improves cardiorespiratory fitness; however, it does not fully restore aerobic capacity and presents large inter-individual variability. We tested the hypothesis that the inter-individual variability of aerobic capacity for responders (R) compared to nonresponders (NR) would differ for exercise frequency and intensity.

METHODS

Thirty-three children (11 female, [mean±SD] 12 ± 3 years, 145 ± 18 cm, 40 ± 11 kg, 49 ± 31 BMI percentile) with severe burns (49 ± 15 % total body surface area burned, with 35 ± 22 % third-degree burns) completed a 6-week RET program. Cardiorespiratory fitness (peak VO2) was measured before and after RET. Frequency (session days/week), intensity (% peak heart rate), time (min/session), and volume (min/week) were compared between responders and non-responders. Significance was set at p < 0.05.

RESULTS

Sixty-four percent of the study population improved peak VO2 after RET whereas 36 % showed no improvements. Using a 2-way factorial ANOVA (group [G] × week [WK]), we found that exercise frequency and session time were similar and increased slightly over 6 weeks between R and NR (main effect for WK; P < 0.002). Exercise volume was significantly lower on week 2 for NR compared to R (G × WK interaction, P < 0.028). Exercise intensity over 6-weeks was significantly lower in the NR compared to the R group (G × WK interaction, P < 0.022).

CONCLUSIONS

Exercise intensity and volume may be important contributors for improving the interindividual response to exercise training for peak VO2. These data suggest that the appropriate dose-response requirement for exercise intensity may be > 80 % peak heart rate and exercise volume of > 150 min per week. Further understanding of the exercise prescription will provide insights important for cardiovascular rehabilitation in children with severe burns.

SUBJECT CODE

Inter-individual Variability, Exercise, Pediatrics, Exercise Training.

Fatigue in children and adolescents after burns: evaluating the problem using longitudinal data

PURPOSE

Describe prevalence and severity of fatigue in children and adolescents with burns during six months after hospital discharge, identify potential explanatory variables, and examine the relationship with exercise capacity.

MATERIALS AND METHODS

Fatigue was assessed using the Pediatric-Quality-of-Life-Inventory-Multidimensional-Fatigue-Scale (PedsQL-MFS) at discharge, and six weeks, three-, and six months after discharge. PedsQL-MFS scores ≥1 SD below the age-group specific non-burned reference mean were considered to signify fatigue.

RESULTS

Twenty-two children and adolescents (13 boys/9 girls, age 6-18 years, with burns covering 2-34% of total body surface area) were included. The prevalence of fatigue decreased from 65% (11/17) at discharge to 28% (5/18) six months after discharge. At group level, fatigue severity decreased over time, reaching healthy reference values from six weeks after discharge and beyond. At individual level, the course of fatigue severity varied widely. Fatigue severity at six months after discharge could not be predicted by age, sex, or burn severity (p = 0.51, p = 0.58, p = 0.95, respectively). The association with exercise capacity was weak (r = 0.062-0.538).

CONCLUSIONS

More than a quarter of pediatric burn patients reported fatigue six months after discharge. Further research in larger populations is required, including also the impact of burn-related fatigue on daily functioning and quality of life.Trial registration number: OND1353942Implications for rehabilitationFatigue should be recognized as a potential consequence of (pediatric) burns, even several months post burnFatigue should be assessed regularly after discharge in all children and adolescents with burns, as it seems not possible to predict its severity from age, sex, or burn severity characteristicsThe weak association between exercise capacity and self-reported fatigue suggests that burn-related fatigue is not simply a consequence of a reduced exercise capacity.

Key Exercise Concepts in the Rehabilitation from Severe Burns

This article presents information on the benefits of exercise in counteracting the detrimental effects of bed rest, and/or severe burns. Exercise is key for maintaining physical function, lean body mass, metabolic recovery, and psychosocial health after major burn injuries. The details of an exercise training program conducted in severely burned persons are presented, as well as information on the importance of proper regulation of body temperature during exercise or physical activity. The sections on exercise and thermoregulation are followed by a section on the role of exercise in scarring and contractures. Finally, gaps in the current knowledge of exercise, thermoregulation, and contractures are presented.

Children's growth and motor development following a severe burn: a systematic review

Background

The epidemiological data on post-burn growth, body composition and motor development is ambiguous and scattered. The aim of this systematic review was therefore to summarize the current body of evidence on post-burn growth, body composition and motor development in children.

Methods

A literature search was conducted in PubMed, EMBASE and Web of Science up to March 2021. We considered observational studies that reported (1) metrics on weight, height, body composition, bone mineral content, bone mineral density or motor development, in (2) paediatric burn patients and (3) published in a peer-reviewed journal.

Results

A total of 16 studies were included. Each of the included studies used quantitative methods, but with differing methodology: prospective cohort studies (n = 8), retrospective chart reviews (n = 3), case-control studies (n = 2), cross sectional studies (n = 2) and a retrospective cohort study (n = 1). When combined, the included studies represented 2022 paediatric burn patients, with a mean age of 7.7 (±3.2) years. The average burn size was 52.8% (±12.7) of the total body surface area. Identified outcome measures included weight (n = 12), height (n = 7), muscular strength (n = 4), bone mineral content (n = 5), bone mineral density (n = 5), body mass index (n = 3), fat mass (n = 5), lean body mass (n = 7) and fine and gross motor development (n = 1).

Conclusions

Following an initial decline, patients' growth and motor development started to recover during the first or second year post-burn. Nonetheless, burns may have a profound and prolonged effect on the paediatric burn patients' muscular strength, bone mineral content and lean body mass. It should be noted that the vast majority of studies included only patients with burns covering ≥30% total body surface area. The evidence presented in this review may thus not be representative of the whole paediatric burn population.

Critical Care Rehabilitation of the Burn Patient

Despite the fact that modern burn care has significantly reduced the mortality associated with severe burn injuries, the rehabilitation and community reintegration of survivors continues to be a challenge. An interprofessional team approach is essential for optimal outcomes. This includes early occupational and physical therapy, beginning in the intensive care unit (ICU). Burn-specific techniques (edema management, wound healing, and contracture prevention) are successfully integrated into the burn ICU. Research demonstrates that early intensive rehabilitation of critically ill burn patients is safe and effective. Further work on the physiologic, functional, and long-term impact of this care is needed.

Grip strength in children after non-severe burn injury

PURPOSE

To characterise grip strength in children with non-severe burn injury, and further understanding of how demographic and clinical variables impact musculoskeletal recovery.

METHODS

A retrospective, cross-sectional audit of routinely collected clinical data was performed. Standardised protocols were used to measure height, weight and grip strength. Demographic and clinical information was collected from patient medical records. Grip strength comparisons were made against normative data using paired t-tests. General linear regressions with backwards elimination were performed to assess impact of clinical, demographic and physical variables on grip strength.

RESULTS

Children who were right hand (RH) dominant had reduced RH (18.9 ± 9.9 kg, p = 0.001) and left hand (LH)(17.6 ± 9.3 kg, p = 0.027) grip strength compared to age, sex and hand-dominance matched norms (RH, 20.0 ± 10.0 kg; LH, 18.4 ± 9.5 kg). Children who were assessed closer to the time of their injury, and those who were burnt at a young age were more likely to score grip strength values below the norm (p < 0.001 for all analyses). In particular, females appeared to be at a higher risk of low grip strength scores if burnt at a young age (p < 0.001).

CONCLUSIONS

Children with non-severe burn injury struggle to recover musculoskeletal strength, with those who were assessed closer to the time of injury or burnt at a young age especially at risk of impaired grip strength performance. Grip strength does not appear to be influenced by any other clinical variables or burn injury characteristics.

Impact of critical illness and withholding of early parenteral nutrition in the pediatric intensive care unit on long-term physical performance of children: a 4-year follow-up of the PEPaNIC randomized controlled trial

Background

Many critically ill children face long-term developmental impairments. The PEPaNIC trial attributed part of the problems at the level of neurocognitive and emotional/behavioral development to early use of parenteral nutrition (early-PN) in the PICU, as compared with withholding it for 1 week (late-PN). Insight in long-term daily life physical functional capacity after critical illness is limited. Also, whether timing of initiating PN affects long-term physical function of these children remained unknown.

Methods

This preplanned follow-up study of the multicenter PEPaNIC randomized controlled trial subjected 521 former critically ill children (253 early-PN, 268 late-PN) to quantitative physical function tests 4 years after PICU admission in Leuven or Rotterdam, in comparison with 346 age- and sex-matched healthy children. Tests included handgrip strength measurement, timed up-and-go test, 6-min walk test, and evaluation of everyday overall physical activity with an accelerometer. We compared these functional measures for the former critically ill and healthy children and for former critically ill children randomized to late-PN versus early-PN, with multivariable linear or logistic regression analyses adjusting for risk factors.

Results

As compared with healthy children, former critically ill children showed less handgrip strength (p < 0.0001), completed the timed up-and-go test more slowly (p < 0.0001), walked a shorter distance in 6 min (p < 0.0001) during which they experienced a larger drop in peripheral oxygen saturation (p ≤ 0.026), showed a lower energy expenditure (p ≤ 0.024), performed more light and less moderate physical activity (p ≤ 0.047), and walked fewer steps per day (p = 0.0074). Late-PN as compared with early-PN did not significantly affect these outcomes.

Conclusions

Four years after PICU admission, former critically ill children showed worse physical performance as compared with healthy children, without impact of timing of supplemental PN in the PICU. This study provides further support for de-implementing the early use of PN in the PICU.

Trial registration ClinicalTrials.gov, NCT01536275; registered on February 22, 2012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04010-3.

Graded aerobic exercise (GAEx): An effective exercise regimen to improve cardio-respiratory fitness and physical and psychosocial functioning in children with burn sequelae of the chest

PURPOSE

The cardio-respiratory function is compromised in children recovering from burns, particularly, those who sustain a burn injury across the chest, which leads to further prejudicial effects on physical and psychosocial health. This study endeavored to explore the efficacy of 12 weeks of graded aerobic exercise (GAEx) on the cardiorespiratory capacity and physical and psychosocial functioning in children with burn sequelae of the chest.

METHODS

Thirty-six burn-injured children aged 10-18 years (%TBSA: 24.2 ± 4.9, and 38.8 ± 12.9 months since injury) were randomly assigned to GAEx group (n = 18; undergone a 12-week intensity- and time-graded aerobic exercise program plus standard rehabilitation) or control group (n = 18; received the standard rehabilitation only). The cardio-respiratory fitness [marked by the peak oxygen uptake (VO_2peak), minute ventilation (V_E), ventilatory equivalent of inhaled oxygen (VEq/VO₂), oxygen pulse (O₂P), respiratory exchange ratio (RER), maximum heart rate (HR_max), and the heart rate recovery at one minute (HRR₁)] and physical and psychosocial functioning were assessed pre- and post-intervention.

RESULTS

Children in the GAEx group showed significant increases in VO_2peak (P = 0.013), V_E (P = 0.026), O₂P (P = 0.034), HR_max (P = 0.035), and HRR₁ (P = 0.04) and declines in VEq/VO₂ (P = 0.009) and RER (P = 0.011) as compared to the control group. Additionally, the GAEx group reported higher physical (P = 0.029) and psychosocial (P = 0.012) functioning.

CONCLUSION

Twelve weeks of GAEx has salutary effects on cardio-respiratory capacity and physical and psychosocial functioning in children with burn sequelae of the chest. These findings suggest that adding GAEx as a complementary therapy to the long-term rehabilitation protocol for this patient population is worthwhile.

Long-term sequelae of critical illness in sepsis, trauma and burns: A systematic review and meta-analysis

BACKGROUND

Sepsis, major trauma, and severe burn injury are life-threatening critical illnesses that remain significant contributors to worldwide morbidity and mortality. The three underlying etiologies share pathophysiological similarities: hyperinflammation, hypermetabolism, and acute immunomodulation. The aims of this study were to assess the current state of long-term outcome research and to identify key outcome parameters between the three forms of critical illness.

METHODS

This systematic review and meta-analysis (MA) were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed was searched from January 1, 1975, to December 31, 2019. Studies were assessed for eligibility by independent reviewers. Inclusion criteria were studies reporting at least a 6-month follow-up of health-related quality of life and organ-specific sequelae within the three etiologies: severe burn injury, sepsis, and major trauma.

RESULTS

In total, 125 articles could be included in the systematic review and 74 in the MA. The mean follow-up time was significantly longer in burn studies, compared with sepsis and trauma studies. The majority of patients were from the sepsis group, followed by burns, and major trauma studies. In the overall health-related quality of life, as assessed by Short Form 36 and European Quality-of-Life Index, the three different etiologies were comparable with one another.

CONCLUSION

The effects of critical illness on survivors persist for years after hospitalization. Well-reported and reliable data on the long-term outcomes are imperative, as they can be used to determine the treatment choice of physicians and to guide the expectations of patients, improving the overall quality of care of three significant patient cohorts.

LEVEL OF EVIDENCE

Systematic review and MA, level III.

Rehabilitative Exercise Training for Burn Injury

Due to improvements in acute burn care over the last few decades, most patients with severe burns (up to 90% of the total body surface) survive. However, the metabolic and cardiovascular complications that accompany a severe burn can persist for up to 3 years post injury. Accordingly, there is now a greater appreciation of the need for strategies that can hasten recovery and reduce long-term morbidity post burn. Rehabilitation exercise training (RET) is a proven effective treatment to restore lean body mass, glucose and protein metabolism, cardiorespiratory fitness, and muscle strength in burn survivors. Despite this, very few hospitals incorporate RET in programs to aid the rehabilitation of patients with severe burns. Given that RET is a safe and efficacious treatment that restores function and reduces post-burn morbidity, we propose that a long-term exercise prescription plan should be considered for all patients with severe burns. In this literature review, we discuss the current understanding of burn trauma on major organ systems, and the positive benefits of incorporating RET as a part of the long-term rehabilitation of severely burned individuals. We also provide burn-specific exercise prescription guidelines for clinical exercise physiologists.

The efficacy of resistance training in addition to usual care for adults with acute burn injury: A randomised controlled trial

Resistance training immediately after a burn injury has not been investigated previously. This randomised, controlled trial assessed the impact of resistance training on quality of life plus a number of physical, functional and safety outcomes in adults with a burn injury. Patients were randomly assigned to receive, in addition to standard physiotherapy, four weeks of high intensity resistance training (RTG) or sham resistance training (CG) three days per week, commenced within 72h of the burn injury. Outcome data was collected at six weeks, three and six months after burn injury. Quality of life at 6 months was the primary endpoint. Data analysis was an available cases analysis with no data imputed. Regression analyses were used for all longitudinal outcome data and between-group comparisons were used for descriptive analyses. Forty-eight patients were randomised resistance training (RTG) (n=23) or control group (CG) (n=25). The RTG demonstrated improved outcomes for the functional domain of the Burn Specific Health Scale-Brief (p=0.017) and the Quick Disability of Arm Shoulder and Hand (p<0.001). Between group differences were seen for C-reactive protein and retinol binding protein (p=0.001). Total quality of life scores, lower limb disability, muscle strength and volume were not seen to be different between groups (p>0.05). Resistance training in addition to usual rehabilitation therapy showed evidence of improving functional outcomes, particularly in upper limb burn injuries. Additionally, resistance training commenced acutely after a burn injury was not seen to be harmful to patients.

Cardiovascular Effect of Varying Interval Training Frequency in Rehabilitation of Severely Burned Children

Structured exercise programs initiated after acute hospitalization can improve muscle strength and mass, cardiorespiratory capacity, and quality of life in severely burned children. In this retrospective study, we compared the cardiovascular effects of an exercise program incorporating a large number of interval training sessions with a traditional exercise program incorporating a small number of interval training sessions. Severely burned children who completed a large number of sessions (at least three sessions per week, N = 40) were matched to those completing a small number of sessions (a maximum of two sessions per week, N = 40). Maximal oxygen consumption (VO2 max) was measured via the modified Bruce treadmill protocol at discharge, on completion of the exercise program, and at follow-up visits at 6, 12, and 24 months postburn. Both groups were comparable in age (large 13.5 ± 3.0 years vs small 13.1 ± 3.3 years) and percent total BSA burned (large 50.8 ± 14.8% vs small 49.2 ± 13.3%). For both groups, VO2 max increased from discharge (large 22.6 ± 3.8 ml/kg/min; small 22.6 ± 5.0 ml/kg/min) to postexercise (large 29.5 ± 6.0 ml/kg/min; small 28.0 ± 5.8 ml/kg/min), 6 months (large 33.2 ± 5.9 ml/kg/min; small 29.6 ± 7.0 ml/kg/min), 12 months (large 35.0 ± 7.5 ml/kg/min; small 31.7 ± 7.1 ml/kg/min), and 24 months (large 37.0 ± 7.2 ml/kg/min; small 32.4 ± 9.2 ml/kg/min, P < .001). VO2 increased to a greater extent with a large number of interval sessions than with a small number at 6 and 24 months (both P = .021). These findings suggest that a large number of interval training sessions impart a greater benefit on cardiorespiratory fitness than a small number of sessions.

Predictability of exercise capacity following pediatric burns: a preliminary investigation

PURPOSE

Describe the course of exercise capacity in pediatric burn patients during the initial 6 months after hospital discharge, and examine whether its recovery can be predicted from burn characteristics, sociodemographic characteristics, and/or prior assessment.

MATERIALS AND METHODS

Exercise capacity was assessed at discharge, and 6 weeks, 3 months, and 6 months after discharge using the Steep Ramp Test (SRT).

RESULTS

Twenty-four pediatric patients with burns affecting 0.1-34% of total body surface area were included. At group level, exercise capacity was low at discharge and did not reach healthy reference values within 6 months, despite significant improvement over time. At individual level, the course of exercise capacity varied widely. Six months after discharge, 48% of participants scored more than one standard deviation below healthy age- and sex-specific reference values. SRT outcomes at 6 weeks and 3 months were the best predictors of exercise capacity 6 months after discharge, explaining, respectively, 76% and 93% of variance.

CONCLUSIONS

Forty-eight percent of participants did not achieve healthy reference values of exercise capacity and were therefore considered "at risk" for diminished functioning. Our preliminary conclusion that early assessment of exercise capacity with the SRT can timely identify those patients, needs to be strengthened by further research.IMPLICATIONS FOR REHABILITATIONPediatric burns can be considered as a chronic medical condition because of the lifelong consequences.Exercise capacity is reduced following- even minor -pediatric burns.Recovery patterns vary widely: some pediatric burn patients achieve healthy levels of exercise capacity without specific intervention, while others do not.The Steep Ramp Test can be used to assess exercise capacity, identifying those "at risk" for adverse outcomes at an early stage.Patients "at risk" should be encouraged to play sports and adopt an active lifestyle.

Estimated versus achieved maximal oxygen consumption in severely burned children maximal oxygen consumption in burned children

PURPOSE

In burned children, exercise training increases maximal oxygen consumption (VO2 max) and can be combined with the nonspecific beta-blocker propranolol to decrease cardiac work. VO2 max is estimated if indirect calorimetry is not available. We compared measured and estimated VO2 max in severely burned children treated with or without propranolol to determine the suitability of commonly used formulas in these populations.

METHODS

Patients received propranolol or placebo (control) during acute hospitalization. VO2 max was measured during a modified Bruce treadmill test at discharge and compared to values obtained using the Cooper, Bruce, American College of Sports Medicine, and Porro formulas. Pearson correlations and Bland-Altman analyses were used to compare measured and estimated values.

RESULTS

Ninety-nine children (propranolol n=46,control n=53) admitted at our facility between 2003 and 2016 were analyzed. Age at burn (propranolol 12±4years, control 12±3years,p=0.893) and total body surface area burned (propranolol 44±15%,control 49±14%,p=0.090) were comparable between groups. Measured VO2 max was higher in the propranolol group (25.5±6.0mL/min/kg vs. 22.0±4.7mL/min/kg,p=0.002) and was generally lower than estimated values. Age, sex, inhalation injury, body mass index, exercise time, and maximal speed were predictive of measured VO2 max in the control group. Age, sex, and maximal speed were predictive in the propranolol group. Backward selection yielded the formula [7.63+ 2.16×sex(females=0,males=1)+0.41×age(years)+0.15×maximal speed(m/min)] (R2=0.6525).

CONCLUSIONS

Propranolol seems to have beneficial effects on cardiorespiratory capacity in burned children. However, estimated VO2 max with common formulas were too high. The VO2 max formula reported here is suitable for propranolol-treated children and the Porro formula for non-propranolol-treated children.

Relationship between lean body mass and isokinetic peak torque of knee extensors and flexors in severely burned children

OBJECTIVE

Severe burns cause hypermetabolic responses and prolonged hospitalization, resulting in loss of body mass and muscle strength. This study aimed to determine whether long-term gains in lean body mass (LBM) after structured exercise programs are functionally meaningful and related to greater muscle strength in severely burned children.

STUDY DESIGN

LBM and muscle strength were measured at discharge and at 6, 12, 24, and 36 months after burn in 349 children. Body composition, including LBM, was measured via dual-emission X-ray-absorptiometry. Peak torque was measured using Biodex dynamometer at varying angular velocities (90, 120, 150, 180°/s). Pearson correlation analysis evaluated the association between LBM and peak torque.

RESULTS

LBM progressively increased from discharge (32.5±11.5kg) to 36 months following injury (40.2±12.3kg). Peak torque and peak torque/LBM increased from discharge (56.4±34.0Nm and 1.7±34.0Nmkg^-1) to 36 months after burn (102.3±43.8Nm and 2.5±0.7Nmkg^-1, p<0.01 for both). LBM and peak torque at all angular velocities showed moderate/strong correlations, with 120°/s being the strongest (all time-points: R²≥0.57).

CONCLUSION

In severely burned children participating in a rehabilitative exercise program, gains in LBM over time are related to increases in muscle strength, suggesting that gained muscle mass is functional. Measurement of muscle strength at an angular velocity of 120°/s best reflects gains in LBM and should be considered for reliable measure of strength in future studies.