A primary burn wound does not slow the contraction rate of an adjacent excisional wound

The response to major burn injury includes systemic release of mediators th at may have an effect on wound healing. The authors evaluated the effect of a burn injury on the contraction of an excisional wound adjacent to the bu rn, and the effect of plasma derived from burn-injured animals on the contr action of the fibroblast-populated collagen matrix (FPCM). Nine rats (90-10 0 days old) under anesthesia received a standardized 40% total body surface area burn to the dorsum, and eight rats (controls) were sham burned. Immed iately thereafter all animals had a square (2.25 cm(2)) of unburned dermis excised from the dorsum, superior to the burn wound. The excisional wound a rea was measured at 2 to 3-day intervals postoperatively. Plasma was collec ted from some animals on postburn day 15; the contraction-stimulating abili ty of burn vs. control plasma was measured in the FPCM. All animals remaine d free of sepsis. The excisional wound area in all animals decreased to 50% and then 25% of the initial area after approximately 4 and 8 days respecti vely. The rate of wound contraction (i.e., wound area reduction) did not di ffer between burn and control animals. Contraction stimulated by 5% plasma in the FPCM (expressed as a percentage of the original matrix area) was 70. 2 +/- 6.4 (standard deviation) mm(2) vs. 62.4 +/- 3.9 mm(2) for burn vs. co ntrol rats respectively (p > 0.05). Burn injury in this model did not alter the contraction of an excisional wound at an unburned site. There was no s ignificant difference in the contraction-stimulating ability (FPCM model) o f plasma from the burned rats compared with plasma from unburned control ra ts. Burn injury appears to have an inconsequential effect on the contractio n of an adjacent wound.