Effect of hyperbaric oxygen therapy on endotoxemia in rabbits

Objective To observe the effects of hyperbaric oxygen (HBO) therapy on endotoxemia and changes in blood cells and pulmonary pathology in rabbits. Methods Thirteen rabbits were randomly divided into the control group (n = 22 ) and the HBO group (n = 24 ), with both groups receiving endotoxin intravenously ( 150 μg/kg), but the HBO group having HBO therapy (once every 8 hours, with a total of six times). Following injection of endotoxin after 2 h, 6 h, 24 h and 48 h, ear artery blood samples were collected. Then, the rabbits were sacrificed 48 later to observe changes in WBC, platelets and pulmonary pathologic changes under the microscope. Results WBC and platelet counts decreased significantly at 2h, 6h and 24h in the control group,when a comparison was made between pre and post endotoxin injection, and didn't return to normal at 48h ( P ＜0. 01, P＜0. 05 ). In the HBO group, WBC and platelet counts were higher than those of the control group at 2 h and 24 h ( P＜0. 01, P＜0. 05 ) and almost completely returned to preexperiment data ( P ＞0. 05 ) after 48 hours. Inflammation of the lungs in the HBO group was slighter than that of the control group. Moreover, no micro-thrombi and hemorrhagic foci could be observed in the HBO group,and death rate of the experimental animals decreased obviously at 48 h ( P＞ 0. 05 ). Conclusions HBO treatment could markedly ease the symptoms of endotoxemia and the decrease of WBC and platelet levels,alleviate inflammation and hemorrhage of the lung, and markedly reduce the death rate of the animals. Key words: Hyperharic oxygen; Endotoxemia; Blood cell; Pulmonary pathology