HYPERBARIC-OXYGEN THERAPY FOR DEEP 2ND DEGREE BURNS - AN EXPERIMENTAL-STUDY IN THE GUINEA-PIG

Most previous animal studies reporting improved epithelialisation and healing of burn wounds under hyperbaric oxygen (HBO) did not include t he conventional treatment with topical antibiotics as part of the prot ocol, and did not compare the effectiveness of HBO therapy with that o f normobaric 100% oxygen (NO). The purpose of our study was to compare the results of combined treatment with HBO + silver sulfadiazine (SS) and those of treatment with NO + SS or SS alone. Deep second degree b urns were produced on the depilated backs of 54 guinea pigs using a va lidated burn protocol. The animals were assigned to three treatment gr oups: HBO + SS, NO + SS, and SS. Dressings were changed daily. HBO was administered at 2 atmospheres absolute (ATA) for 90 min BID, and NO f or 90 min BID. The parameters compared among the groups were laser Dop pler flowmetry, and bunt wound contracture and re-epithelialisation da ta derived from computerised planimetry of photographs of the wound. N o differences in laser Doppler flowmetry results or the magnitude of c ontracture were found between the groups. Significantly increased re-e pithelialisation was observed under NO + SS starting 10 days after the burn (P = 0.02, ANOVA). This significance stems from the difference b etween the HBO + SS and NO + SS groups (Tukey test). These data indica te that excessively high levels of tissue PO2 might compromise burn he aling, and explain our results. A further study comparing combined tre atment using a milder HBO protocol + SS and NO + SS is indicated in th e search for the optimal HBO regimen.