Hyperbaric oxygen reduces ischemia-induced skeletal muscle injury

The effect of hyperbaric oxygen treatment on skeletal muscle submitted to 3 or 4 hours of ischemia was studied in a rat hindlimb model after 48 hours of reperfusion. Forty-eight male Sprague-Dawley rats were allocated to four groups. In the two treatment groups, hyperbaric oxygen was given for 45 minutes at 2.2 atm immediately and 4,8,16,24,32, and 40 hours after release of the ischemia-inducing tourniquet. The injury to skeletal muscle was quantified from the uptake of 99mtechnetium-pyrophosphate (injected intravenously after 45 hours of reperfusion) in anterior tibial muscle harvested 3 hours later. The uptake was significantly lower in hyperbaric oxygen-treated rats than in untreated rats with 3 or 4 hours of ischemia (p < 0.01 and P < 0.05). After 4 hours of ischemia, the changes in levels of the intracellular muscle compounds adenosine triphosphate, phosphocreatine, and lactate were less in the hyperbaric oxygen-treated rats than in the untreated animals.