Comparison of the effects of the CO_2 Laser and Chlorohexidine on the sterilization of infected cutaneous wounds: A histologic study

摘要

Wound infection constitutes a big risk for patients and it is usually associated to increased morbidity, mortality and hospital costs. It is accepted that local treatment of these infections is effective. The aim of this study was to compare histologicly the effects of the CO_2 Laser and Chlorohexidine Gluconate (4 percent) on Staphylococcus aureus infected cutaneous wounds. Standardized wounds were infected with Staphylococcus aureus and treated during six days as follows: Group Ⅰ: Chlorohexidine Gluconate (4 percent) , 1 min, six days; Group Ⅱ: CO_2 Laser, one day, maintaining surface debris; Group Ⅲ: CO_2 Laser, one day, removing the surface debris. Seven days after wounding the animals were killed and specimens taken for light microscopy. On control wounds, it was observed epithelial ulceration, and neutrophylic and lymphoplasmocitary inflammatory infiltrate. On group Ⅱ, there was epithelial hyperplasia, areas of ulceration and intense neutrophylic and lymphoplasmocitary inflammatory infiltrate. On the other hand, on group Ⅲ, there was a neutrophylic inflammatory infiltrate underneath the surface debris and bellow that intense lymphoplasmocitary inflammatory infiltrate. When the surface debris was removed (Group Ⅳ), there was epithelial ulceration and mild lymphoplasmocitary inflammatory infiltrate and fibroblasts and collagen fibers. The results of this study shows that infected wounds treated with 4 percent Chlorohexidine shows a more pronounced inflammatory reaction when compared to that observed when the CO_2 Laser is used, especially when surface debris are removed; Surface debris removal on Laser treated wounds results on a better and quicker healing; the surface debris may act as a culture medium for bacterial growth or, because of its characteristics, it may acts as local irritant and delay healing.