HBOT Decreases Inflammation in RSD

Hyperbaric oxygen treatment decreases inflammation and mechanical hypersensitivity in an animal model of inflammatory pain RSD

Wilson HD, Wilson JR, Fuchs PN
Brain Res
vol. 1098, 126 - 128, 2006

Abstract

Background: 

Hyperbaric treatment was initially developed to combat the adverse effects of deep sea diving. In recent years, hyperbaric oxygen treatment has been used to treat a broad spectrum of ailments, including delayed-onset muscle soreness, fibromyalgia, and complex regional pain syndrome (CRPS). However, limited data are available on the effect of hyperbaric oxygen treatment on inflammatory pain. The effect of hyperbaric oxygen treatment on carrageenan-induced inflammation and pain in rats was investigated. It was hypothesized that treatment with hyperbaric oxygen would decrease paw edema and hyperalgesia in an acute inflammatory pain model as compared with that of a sham-treated control group.

Methods: 

The experiment was conducted on 44 male Sprague-Dawley rats each between 300 and 350 g. The inflammatory pain condition was induced by subcutaneous injection of 1% carrageenan suspended in saline in the left hind paw. Paw volume was assessed via water displacement with a plethysmometer, and percentage differences were calculated on the basis of posttreatment measures compared with pretreatment measures. Hyperalgesia was assessed using the up/down method of mechanical paw withdrawal thresholds. Hyperbaric oxygen treatment involved exposing animals to 100% oxygen at a pressure of 2.4 atmospheres absolute (ATA) for 90 minutes in a hyperbaric chamber. A control group was placed in the hyperbaric chamber but did not receive treatment.

Results: 

A 1-way analysis of variance revealed no significant preinjec-tion group differences. An overall mixed-design analysis with 2 group levels (treatment, sham) and 7 levels of time revealed a significant main effect for group, a main effect for time, and a group by time interaction. In the hyperbaric oxygen treatment group, paw edema remained at pretreatment levels immediately after treatment and continued to decrease slightly until 2 hours posttreatment, at which time it began to decrease. However, antinociceptive effects were apparent immediately after treatment and continued to increase up to 5 hours after treatment, suggesting that distinct mechanisms might be involved in the anti-inflammatory and antinociceptive properties of Hyperbaric Oxygen Treatment.

Conclusions: 

Hyperbaric oxygen treatment significantly reduced inflammation and pain after carrageenan injection in this rat model of inflammatory pain. Hyperbaric oxygen may be used in patients for whom nonsteroidal anti-inflammatory drugs are contraindicated or for those with persistent inflammation.