Effect of oxygen treatment and dressing oxygen permeability on wound healing

Although it has been shown that both the level of tissue oxygen and its gradient are critical factors in the healing process, optimal conditions for oxygen therapy have not been determined. In this study, both the oxygen level and oxygen gradient for a full-thickness defect were modified on the basis of preceding in vitro studies to determine the effect on the healing process. The goal of this study was to help determine the optimal clinical oxygen treatment protocol. Specifically, the healing of full-thickness defects in a rabbit model as determined by histomorphometric analyses (cell and tissue volume fraction, epithelialization, and contraction) under two types of dressings with or without oxygen treatment (70% O(2)) was investigated. One of the dressings was more oxygen permeable than the other. No significant differences were found in the histomorphometric response between the wounds covered with the oxygen-permeable and oxygen-impermeable dressings in the group without supplemental oxygen. Oxygen treatment, however, seemed to enhance the healing response significantly. According to the histomorphometric response, the wounds covered with the oxygen-impermeable dressings were significantly better than those with the oxygen-permeable dressing in the oxygen-treated group after 1 week, but the wounds covered by the oxygen-permeable dressings were better healed at 3 weeks. Therefore, oxygen-impermeable dressings may be useful only in the early stages of healing, before granulation tissue formation.