Large Burns Open Up A Can Of Worms

Burns trigger an immediate, dramatic inflammatory response, as well as a more delayed and longer-lasting hypermetabolic one. The latter can cause depletion of essential proteins, reduced bone density and muscle strength, and can compromise the function of vital organs. But whilst it's well known that increased burn size leads to increased mortality in burned patients, the roles played by inflammation and hypermetabolism are less clear.

Marc G. Jeschke from Shriners Hospitals for Children, Texas, USA and colleagues conducted a prospective clinical trial of 189 paediatric burned patients over nine years to see if burn size is associated with differences in inflammation, body composition, protein synthesis and organ function.

Burn injuries involving more than 80% of the total body surface cause marked and prolonged inflammation, increases in hypermetabolism, catabolism, cardiac dysfunction and subsequently higher incidences of infection, sepsis and death. These effects were burn size-dependent. Another outstanding finding was that effect of burn size on cardiac dysfunction. Only large burns caused cardiac dysfunction which was shown by Pereira et al. as one of the major contributor to mortality, implying the importance of adequate cardiovascular support and treatment.

Patients with larger burns also had higher levels of pro-inflammatory cytokines, such as Tumor Necrosis Factor and Interleukin-8. The authors think these give the inflammatory response an added boost, enhancing catabolism and hypermetabolism.

Article: Burn size determines the inflammatory and hypermetabolic response Marc G. Jeschke, Ronald P. Mlcak, Celeste C. Finnerty, William B. Norbury, Gabriela A. Kulp and David N. Herndon Critical Care (in press)