Effects of early exercise training following severe burn injury: a randomized controlled trial.

Background: Despite being a stable component of burn rehabilitation at later stages of recovery, exercise training is not commonly provided during the acute phase of burns. A lack of evidence surrounding its efficacy and safety in severely burned adults has hampered its implementation in acute burn care. The aim of this study was to investigate the capacity of early exercise training to modulate parameters of postburn muscle wasting and quality of life.

Methods: Adults <65 years of age with burns ≥40% total burn surface area (TBSA) were randomly allocated to either receive early exercise (n = 29) in addition to standard care or standard care alone (n = 29). Early exercise involved resistance and aerobic training, which commenced as early as possible and lasted for a duration of 6 to 12 weeks, in line with burn center length of stay. Ultrasound-derived quadriceps muscle layer thickness (QMLT) and rectus femoris cross-sectional area (RF-CSA), lower limb muscle force, Eurocol Quality of Life-5 Dimensions and Burn Specific Health Scale Brief (BSHS-B) were assessed 6 and 12 weeks after baseline. Mixed models were fitted to compare between-group changes over time.

Results: A total of 58 adults [42 (95% confidence interval 40-45) years old; 40-94% TBSA range, 86% previously mechanically ventilated] participated in this study. Exercise commenced 7 days [IQR (interquartile range) 5-9] after burn center admission with an attendance rate of 93%. Allocation to the exercise group had a protective effect on the loss of muscle size from baseline to 6 weeks of follow-up (QMLT: β-coefficient: 0.05 cm, p = 0.010; RF-CSA: β-coefficient: 0.05 cm², p = 0.045), and resulted in an improved recovery from 6 to 12 weeks (QMLT: β-coefficient: 0.04 cm, p = 0.01; RF-CSA: β-coefficient: 0.06 cm², p < 0.001). Muscle force increased significantly more in the exercise group than in the control group (β-coefficient: 3.102 N, p < 0.001) between 6 and 12 weeks. Besides a marginally significant effect for the BSHS-B domains 'affect' and 'interpersonal relationships' between 6 and 12 weeks, no benefits were observed in the other assessed quality-of-life measures. No serious adverse events were reported in the exercise group.

Conclusions: The results of this study support the use of early exercise training as a feasible and efficacious therapeutic strategy to manage burn-related changes in muscle size and strength in adults with acute severe burn injury.