Functional evaluation after rat sciatic nerve injury followed by hyperbaric oxygen treatment.

Previous experimental studies have shown positive effects of hyperbaric oxygen treatment in the early regeneration phase in the first few days following a nerve injury. In this study, functional effects of hyperbaric oxygen treatment were studied in 2 series of rats after an injury to the sciatic nerve - a standardized crush injury and nerve transection and repair, respectively. Postoperatively the animals were treated with 100% oxygen at 2.5 atmospheres absolute pressure for 90 minutes and the treatment was employed twice daily for 7 days. The animals were evaluated with walking track analysis up to twice weekly. The experiments were terminated after 90 days when the tetanic force was measured in the tibial anterior and gastrocnemius muscles. No statistically significant differences were found in either of these tests. It is concluded that hyperbaric oxygen treatment, given in accordance with clinical protocols used in limb crush injuries and other peripheral conditions, was not effective in the restoration of gait or the muscular strength after 90 days in rats after these nerve injuries. This study does not support nerve crush injury or nerve transection and repair as indications for hyperbaric oxygen treatment.