Effect Of Hyperbaric Oxygen On Inflammatory Response After Resuscitation From Hemorrhagic Shock

ObjectiveHemorrhagic shock ( HS ) is one of frequent critical illness in clinical, a lot of factors involved in this pathology procedure. Including ischemia hypoxia, reperfusion injury. Overproduction of reactive oxygen species ( ROS) and nitrogen oxygen free radical may initiate systemic inflammatory response syndrome ( SIRS ) , excessive system inflammation is one of critical reason which cause HS turn to irreversible, this concerned with prognosis of shock. Therefore we should not only undertake resuscitation with fluid, but also take anti - inflammatory therapeutic measure. Block or reduce inflammatory mediators in early phase of HS, its important for prevent exacerbation from HS. It is demonstrated that Hy-perbric oxygen ( HBO) can attenuates I\R injury in muscle , bowel , skin flap , liver and after carbon monoxide poisoning. HBO can decrease inflammation in shock which was induced by lipopolysaccharide(LPS) or zymosan . It is suggested Hyperbaric oxygen may improve ischemia and hy-poxia of tissue, meanwhile, significantly attenuates mortality of rats and induction of tumor necrosis factor - α ( THF - α ) and interleukin - 6 (IL - 6 ) in liver . In this study, we apply HBO after resuscitation from HS, to evaluate the role of HBO in inflammatory response after resuscitation from HS.Subjects and Methods1. Animal subgroupWistar rats ( mean weight 260 - 300g);animals were randomly subjectedthree groups. Each group has 24 rats. The control group: no shock no resuscitation;the shock group: induce shock then blood transfusion and fluid infusion for resuscitation in regular. After resuscitation pull out cannula immediately ligate blood vessel then close tresis vulnus. The hyperbaric group: induce shock then blood transfusion and fluid infusion for resuscitation in regular. After resuscitation pull out cannula immediately ligate blood vessel then close tresis vulnus. Post in hyperbaric oxygen chamber at once, first, denitrogenation by flushing with 100% oxygen 10 minute and maintain 0. 2Mpa, oxygen concentration > 99. 5% 40 minutes. Decompression takes 15 minutes.2. Hemorrhagic shock modelSeventy two Wistar rats, weighing 260 - 300 grams each , were used in this study To induce hemorrhagic shock in the Wistar rats , they were first anesthetized with sumianxin (0.4ml/ kg , ilpl) at room temperature(25 °C ) Blood pressure was monitored via polyethylene tubing inserted into the right femoral artery , using a low pressure analyzer ( Polygraph RM 6000, Japan) The left jugular vein was cannulated to administer normal saline, and blood The right carotid artery was cannulated with polyethylene tubing, and shock was induced over 5 minutes by withdrawing blood through this tubing into a heparinized glass syringe until mean arterial pressure was reduced to 30 - 35 mmHg Constant pressure was maintained by further withdrawal of small amounts of blood as necessary for 55 minutes After 60 minutes of hypotension, rats were resuscitated by the transfusion of 60 % of the shed blood over 5 minutes, followed by normal saline (twice the shed blood volume) for 55 minutes.3. DetectionAfter anesthesia is counted Oh, induce shock in 2. 5h ( control group does not induce, expose and isolate blood vessel only) , resuscitate in 3. 5h,resuscitation was complete in 4. 5h. According to 2. 5h, 3. 5h, 4. 5h, 24h. There are four subgroup in each group animals (n = 6 ). Get 2ml blood from each animals, then sacrifice. 50jxl add in 5ml normal saline, get red blood cell on the bottom when it' s centrifuged. The rest get blood plasma when them was centrifuged.4. Histological proceduresIn 24h,the lungs , liver , intestine were excised from each rat when stilllive, and fixed with 1 % paraformaldehyde Fixed tissues were embedded in paraffin and processed for light microscopy Sections were stained with hematoxylin and eosin. Histological grade: To grade the bowle , lung , liver of animals in 24h.5. Statistical analysisThe groups were compared with Fisher s exact test , one way ANOVA , and the Student Newman Keuls post hoc test (using SPSS 11.5 software) Differences were considered significant when P <0. 05Result1. superoxide dismutase (SOD) of Red blood cellThe difference is no significant, from which SOD of red blood in three groups in 2. 5h, 3. 5h. The difference between HBO group and shock group is no significant in 4. 5h. the difference between control group and shock group was significant P <0.05, the difference between control group and HBO group was significant P <0.05. The activity of SOD from animals of hyperbaric group was increased, which of shock group was descend, The activity of SOD from animals of shock group was decreased than the control group. The activity of SOD from animals of hyperbaric group was enhanced by hyperbaric oxygen than the control group. All difference were significant P <0. 05.2. Induce nitric oxide synthase (iNOS) of Blood plasmaThe difference is no significant, from which iNOS of blood plasma in three groups in 2. 5h, 3. 5h. The difference between HBO group and shock group is no significant in 4. 5h. the difference between control group and shock group was significant P <0. 05, The activity of iNOS from animals of hyperbaric group was decreased, which of shock group was increased, The activity of iNOS from animals of shock group was enhanced than the control group. The activity of iNOS from animals of hyperbaric group compared with the control group. All difference was significant. P <0.053. tumor necrosis factor *- a( TNF - a) of Blood plasmaThe difference is no significant, from which TNF - a of blood plasma inthree groups in 2. 5h, 3. 5h. The difference between HBO group and shock group is no significant in 4. 5h. the difference between control group and shock group was significant P <0.05, the difference between control group and HBO group was significant P <0. 05. The quantity of TNF - afrom animal' s blood of hyperbaric group was decreased, which of shock group was increased, The quantity of TNF - afrom animals of shock group was increased than the control group. The quantity of TNF - afrom animal' s blood of hyperbaric group was decreased by hyperbaric oxygen than the control group. All difference were significant P<0.05.4. Histological gradeTo grade the bowle, lung, liver of animals in 24 h, HBO successfully reduced the histopathological severity of the bowle , lung , liver injury of animals. The difference were significant P <0.05.ConclusionIn this study, we apply HBO on rats after resuscitation from HS, HBO improve oxygen supply of tissues, however, increase ability of eliminate ROS and free radical, HBO attenuates edema of tissues and infiltration of proinflammatory cells, HBO can improve microcirculation, and HBO can decrease proinflammatory cytokines expression, so HBO can attenuates inflammatory response after resuscitation from HS.