Determinants of Skeletal Muscle Catabolism After Severe Burn

TLDR

Severe burns trigger skeletal muscle catabolism that erodes lean mass, impairs wound healing, and delays rehabilitation, with studies focusing on patients with 20–99 % total body surface area involvement. The study aimed to identify patient factors that influence the extent of skeletal muscle catabolism following severe burn. Researchers correlated patient demographics, burn characteristics, and hospital course variables with leg skeletal muscle protein synthesis and breakdown measured via stable‑isotope kinetics. Older age, higher weight, delayed definitive surgery, larger TBSA (up to 40 %), elevated resting energy expenditure, and sepsis were strong predictors of increased skeletal muscle catabolism, whereas burn type, pneumonia, wound contamination, and time after burn did not significantly correlate; heavier, more muscular patients and those with delayed surgery were at greatest risk.

Abstract

To determine which patient factors affect the degree of catabolism after severe burn.Catabolism is associated with severe burn and leads to erosion of lean mass, impaired wound healing, and delayed rehabilitation.From 1996 to 1999, 151 stable-isotope protein kinetic studies were performed in 102 pediatric and 21 adult subjects burned over 20-99. 5% of their total body surface area (TBSA). Patient demographics, burn characteristics, and hospital course variables were correlated with the net balance of skeletal muscle protein synthesis and breakdown across the leg. Data were analyzed sequentially and cumulatively through univariate and cross-sectional multiple regression.Increasing age, weight, and delay in definitive surgical treatment predict increased catabolism (P < .05). Body surface area burned increased catabolism until 40% TBSA was reached; catabolism did not consistently increase thereafter. Resting energy expenditure and sepsis were also strong predictors of net protein catabolism. Among factors that did not significantly correlate were burn type, pneumonia, wound contamination, and time after burn. From these results, the authors also infer that gross muscle mass correlates independently with protein wasting after burn.Heavier, more muscular subjects, and subjects whose definitive surgical treatment is delayed are at the greatest risk for excess catabolism after burn. Sepsis and excessive hypermetabolism are also associated with protein catabolism.