Regional skin blood flow in deep burn wounds: a preliminary report

Local skin blood flow (LSBF) using the Walker's deep burn rat model was studied on the first three postburn days using the carbon-14 iodoantipyrine ([¹⁴C]IAP) perfusion method. The radioactive [¹⁴C]IAP (12.5 μCi) was infused through the femoral vein over a period of 30 seconds and the blood samples were collected by a free flow from the femoral artery at 5-s intervals to evaluate the concentration of the isotope, in the blood. At the conclusion of the infusion, the rats were guillotined and biopsies were obtained from the burned skin, unburned skin from burned rats and skin from sham control rats to assay the isotope in the skin. The LSBF was calculated from the skin tissue and plasma radioactivity data using Jay's equation. The results showed significant decreases of the skin blood flow in the deep burn wound with 4.05 ± 1.16, 5.31 ± 1.32 and 4.77 ± 2.48 ml/100 g/min as compared to the LSBF of unburned skin 10.27 ± 1.49, 12.39 ± 2.05, 14.79 ± 1.85 ml/100 g/min on postburn days 1, 2 and 3 (P < 0.05). The blood flow of the control group skin was 11.5 ± 1.97 ml/100 g/min (P < 0.05). There were also significant differences of LSBF among burn wounds on postburn days 1, 2 and 3 (P < 0.05). Pathological study of the deep burn wound showed that more of the blood flow was in the subcutaneous adjacent areolar tissue, than in the deep reticular dermis, and only a little occurred in the upper reticular dermis occasionally. These results provide a reproducible model to study burn depth by determining LSBF in a deep burn wound.