THE EFFECT OF HYPERBARIC-OXYGEN THERAPY ON A BURN WOUND MODEL IN HUMAN VOLUNTEERS

A previous nonblinded study has suggested beneficial. effects from hyp erbaric oxygen treatment of superficial partial-thickness radiation bu ms in human volunteers. This protocol was designed to either confirm o r challenge these previous findings in a randomized, blinded format. T welve healthy, nonsmoking volunteers (7 males, 5 females) participated . All were screened for contraindications to hyperbaric oxygen therapy (acute sinusitis, otitis media, pneumonia, pregnancy, active cancer, pneumothorax) and given a single test hyperbaric exposure. A standardi zed wound model was employed for the painless creation of a volar fore arm lesion on volunteers by applying a suction device to form a bliste r, excising its epidermal roof, and irradiating the exposed dermis wit h ultraviolet light. Subjects were randomized into either a hyperbaric oxygen group (100% oxygen at 2.4 ATA, n = 6) or the sea-level air-bre athing equivalent control group (8.75% oxygen at 2.4 ATA, n = 6). Both groups then underwent standard hyperbaric therapy. The subjects, the hyperbaric oxygen chamber operators, and the monitoring clinicians wer e all blinded to the oxygen concentration administered. Each subject r eceived two dives per day over a 3-day period. The wounds were studied noninvasively prior to treatment and once per day over 6 days for siz e, hyperemia, and exudation, with epithelialization as the endpoint. T he averages for each measurement of the hyperbaric oxygen group versus the control group were computed by means of a one-tail t test; p was considered significant at less than 0.05. Daily wound size, hyperemia, and exudation measurements were significantly different on day 2. The hyperbaric oxygen group showed a 42 percent reduction in wound hypere mia, a 35 percent reduction in the size of the lesion, and a 22 percen t reduction in wound exudation (p values of 0.05, 0.03, and 0.04, resp ectively). No significant difference was noted for epithelialization. Observed differences in wound size, hyperemia, and exudation were attr ibutable to hyperbaric oxygen therapy. This study further supports ear lier conclusions that hyperbaric oxygen therapy is beneficial in a sup erficial dermal wound.