EFFECT OF HYPERBARIC-OXYGEN ON LIPID-PEROXIDATION IN FREE SKIN-GRAFTSIN RATS

Objective-To document that free skin grafts treated with hyperbaric ox ygen (HBO) are at greater risk for reperfusion injury, resulting in li pid peroxidation, than are free skin grafts without HBO treatment. Ani mals-40 Sprague-Dawley rats. Procedure-Free skin grafting was performe d bilaterally on each rat. The HBO-treated rats received HBO twice dai ly for 90 minutes at 2 ATA. Biopsy specimens were taken from each rat at the time of grafting and on days 2, 4, 7, 10, 14, 21, and 28, then were processed for tissue concentration of total glutathione (GSHt), g lutathione peroxidase activity (GPx), and presence of thiobarbituric a cid-reactive substances (TBARS). Results-Both groups had,a similar pat tern of change in TEARS and GPx values-initial increase, returning to preoperative values at days 21 (control) and 28 (HBO). The GPx activit y peaked later than did TEARS concentration (day 7 vs day 4). The patt ern was significantly more pronounced in HBO-treated than in control r ats. Both groups had a similar pattern of change in GSHt values-signif icant decrease from preoperative concentration at day 2, return to pre operative concentration by days 4 (HBO) and 7 (control), increase abov e preoperative concentration by day 21, and return to preoperative con centration by day 28. Obvious visual or histologic differences in the grafts were not detected between groups. Conclusions-Cellular effects of oxidative stress were apparent in both groups of rats; however, the degree of these effects was exacerbated by HBO. In the face of enhanc ed cellular lipid peroxidation, use of HBO for the treatment of free s kin grafts must be questioned.