Effects Of Hypobaric And Hypoxic Environment On Oxygenation Status And Brain Tissue Edema In Hemorrhagic Shock Animals

First Effects of Hypobaric and Hypoxic Environment on Oxygenation Status of Hemorrhagic Shock AnimalsObjective To explore the effect of hypobaric and hypoxic environment on systemic oxygenation status in hemorrhagic shock rats.Method Thirty clean rats were randomly divided into 3 groups:hemorrhagic shock without hypobaric hypoxia chamber group?HS-NC group?,non-hemorrhagic shock with hypobaric hypoxia chamber group?NHS-C group?,hemorrhagic shock with hypobaric hypoxia chamber group?HS-C group?,The hemorrhagic shock model was prepared by volume control.Three groups of rats collected arterial blood indicators at the end of shock preparation,1-hour,and 3-hour:p H?p H?,partial oxygen pressure?PO₂?,partial pressure of carbon dioxide?PCO₂?,oxygen saturation?Sa O₂?,and lactic acid?Lac?,bicarbonate ion?HCO3^-?,base excess?BE?,glucose?Glu?,hemoglobin?Hb?.Using t test and repeated measurement analysis of variance,compare the general situation of HS-C group and HS-NC group at the completion of shock preparation,and then compare the changes of blood gas indicators at 1-hour and 3-hour;compare HS-C group with NHS-C the changes of blood gas indicators in the 1-hour and 3-hour groups were compared;compare the changes of blood gas indicators in different periods in HS-C group.Result Comparison of blood gas indicators at the end of shock preparation between HS-C group and HS-NC group.There was no significant difference in p H,PO₂,PCO₂,Sa O₂,Lac,HCO3^-,BE,Glu,Hb between the two groups?P>0.05?.Compareing with the HS-NC group for 1-hour of blood gas results,the p H,Sa O2,HCO3^-and BE of the HS-C group are significantly lower than those of the HS-NC group[?7.18±0.05?vs?7.42±0.12?,P=0.009;?90.46±3.03?vs?95.50±3.69?,P=0.046;?18.26±2.78?vs?22.32±2.53?,P=0.042;?-9.38±2.42?vs?-2.98±2.82?,P=0.005],Lac is significantly higher than the HS-NC group[?7.56±1.69?vs?3.08±1.29?,P=0.002].There is no significant difference in PO₂,PCO₂,Glu and Hb between the two groups.The analysis results of the two groups at 3-hours showed that the HS-C group and the HS-NC group had statistical significance in p H,HCO3^-and BE[?7.26±0.14?vs?7.43±0.06?,P=0.033;?17.86±3.47?vs?23.22±3.06?,P=0.032;?-7.44±2.67?vs?-1.84±4.31?,P=0.039].Comparing the 1-hour results between the HS-C group and the NHS-C group,the differences in p H,Lac,HCO3^-,BE,and Hb between the two groups are statistically significant[?7.18±0.05?vs?7.41±0.03?,P=0.000;?7.56±1.69?vs?1.20±0.67?,P=0.000;?18.26±2.78?vs?24.78±1.56?,P=0.004;?-9.38±2.42?vs?0.68±2.05?,P=0.000;?11.36±1.47?vs?14.38±1.33?,P=0.015];Comparison of the results at 3-hours,the difference between the two groups in p H,Lac,HCO3-,BE and Hb is statistically significant[?7.26±0.14?vs?7.45±0.03?,P=0.036;?5.52±2.18?vs?1.35±0.41?,P=0.012;?17.86±3.47?vs?24.20±0.22?,P=0.015;?-7.44±2.67?vs?-0.58±0.43?,P=0.002;?10.76±1.83?vs?13.85±1.74?,P=0.037].Comparison of blood gas results of HS-C group at different time periods,there is statistical significance in p H,Lac and BE at 1-hour compared with 0-hours[?7.18±0.05?vs?7.38±0.07?,P=0.005;?7.56±1.69?vs?3.72±1.90?,P=0.008;?-9.38±2.42?vs?-3.84±2.90?,P=0.007];the 3-hour of PH,PO₂,PCO₂,Sa O₂,Lac,and BE are not statistically significant with 0-hour and 1-hour.Conclusion The hypobaric and hypoxic environment has an effect on the oxygenation status of rats with hemorrhagic shock.Compared with rats with normal environment,hypobaric and hypoxic environment can aggravate the degree of acidosis,but the rats have the ability of adaptation and compensation,with the extension of experimental time,acidosis did not aggravate.Second Effects of Hypobaric and Hypoxic Environment on Brain Tissue Edema of Hemorrhagic Shock AnimalsObjective To explore the effect of hypobaric and hypoxic environment on the brain tissue edema of animals with hemorrhagic shock animals.Method Ten clean rats were randomly divided into two groups.The model of hemorrhagic shock was made by volume control method.The rats in the two groups were put into normal environment and hypobaric and hypoxia environment for 3 hours and then killed.The right brain tissue was used to measure the brain water content,which was expressed by the ratio of dryness to wetness.The left brain tissue is embedded and fixed for staining and observation.The general conditions and the ratio of dryness to wetness of the two groups of rats are compared.The swelling and inflammatory cell infiltration of brain cells in the two groups are observed with an optical microscope.Results There was no significant difference in body weight,total brain weight,right brain dry weight and wet weight and dry-wet ratio between the two groups of hemorrhagic with hypobaric hypoxia chamber group and non-hemorrhagic shock with hypobaric hypoxia chamber group,with no statistical significance?P > 0.05?.Morphological observation of brain tissue sections showed that a small number of cells stained lightly and increased in volume in both groups;no significant neutrophil infiltration was seen in both groups.Conclusion Hemorrhagic shock rats can observe mild edema of brain tissue under the special environment of hypobaric hypoxia,but there is no obvious difference compared with hemorrhagic shock under normal environment.At the same time,there was no infiltration of inflammatory cells such as neutrophils in hemorrhagic shock rats.