The Impacts Of Free Hemoglobin On Hemorrhagic Shock Animals

Free Hemoglobin (Free Hemoglobin, FHb) refers to the hemoglobin in plasma contrasting to the hemoglobin in erythrocytes. Normally blood contains a small amount of plasma free hemoglobin combining with haptoglobin. When a large number of erythrocytes are destroyed, the hemoglobin was released to the plasma. As the concentration of hemoglobin beyond the binding ability of haptoglobin, hemoglobinuria occurs. In the conditions of normal and hemorrhagic shock resulting from being wounded in war, the impacts of FHb on the major organs haven't been disclosed. In the experiment, a model of hemorrhagic shock was set up. After the model was set up, the animals were infused different doses of FHb in both groups. Physiological and pathological changes were observed. The relationship between the dosage of hemoglobin and the damage may be disclosed in the end.This study was divided into three parts. In the first part, free hemoglobin and the porcine model of hemorrhagic shock were prepared. The blood of healthy pigs was drawn out with the volume of 100ml, conserved in the anticoagulant. Centrifugated and washed for three times, the packed red cells were broken by the ultrasound oscillation. The solution was centrifuged and the supernatant was kept in the temperature– 20℃. Then 15 pigs were randomly divided into two groups: hemorrhagic shock group (H, n=9) and control group (N, n=6). The pigs bled till the mean arterial pressure descent to 50±5mmHg and the state was held for 1.5h to 2h. The animals were recovered by fluid including 60% of lost blood and balanced solutions in volume of twice lost blood. Animals in control group are given anesthesia and operations instead of hemorrhagic shock. According to the indexes such as the respiratory rate, heart rate, blood pressure, cardiac output and total bilirubin,ALT,AST,Cr and BUN, the model was assessed. Pathological analysis was carried out when the animals were killed within 48 hours. The indexes of control group such as the heart rate, breathing rate, blood pressure were found that had no statistical significance either before or after operations (P>0.05). On the other hand, the hemorrhagic shock animals were found that had significant difference in those indexes (P<0.01). Inflammations were observed mainly in the pathological examination. Then conclusion was made that the preparation of free hemoglobin and hemorrhagic shock could be made quite well in these methods.In the second part, the impacts of different doses of free Hemoglobin on organ functions were found. 30 healthy pigs were divided into five groups and were given different doses of FHb (0, 10mg/kg, 15mg/kg, 20 mg/kg, 25mg/kg). Then vital signs and Homodynamic changes, as well as arterial blood gas analysis, detection of total bilirubin,ALT, AST,BUN are observed. On the other hand, 30 Healthy pigs were divided into five groups, with the treatment of Hemorrhagic shock according to the methods mentioned in the first part. During the period of recovery process, the different doses of FHb (0, 2.5mg/kg, 5mg/kg, 10 mg/kg, 15mg/kg) were infused into the animals. The results came out that there was statistical significance between the groups of 25mg/kg and the control in functions (P<0.05). In the group of Hemorrhagic shock, there was statistical significance between the groups of 10mg/kg and the control in the functions (P<0.05). Especially there was significant difference between the groups of 15mg/kg and the control (P<0.01). The conclusion was made that tolerance dose of free hemoglobin in normal animals was between 20 mg/kg and 25mg/kg. When the concentration was less than 20mg/kg, the solution might be safe for animals; the tolerance dose of free hemoglobin in hemorrhagic shock animals was between 10mg/kg and 15mg/kg.During the third part, pathological changes of organs were investigated in hemorrhagic shock animals. 24 healthy pigs were divided into four groups and were given different doses of FHb (0, 5mg/kg, 10mg/kg, 15mg/kg); 48 hours later, the animals were killed and the organs such as heart, liver, lung and kidney are rapidly dedicated for pathological examination. The hemorrhage,edema and inflammation could be observed in the sections of hemorrhagic shock animals, but microstructures of organs remained normal. There was statistical significance between the group with concentration of 5mg/kg and simple hemorrhagic shock group in the pathological changes (P<0.05); There was significant difference between the group with concentration of 10mg/kg and the group with simple hemorrhagic shock in the pathological changes of organs (P<0.01), so did the group with concentration of 15mg/kg. The conclusion could be made that damage of the microstructures resulted in the changes of organ functions. Along with the concentration of hemoglobin rising, the harmful impacts increased. It might increase the incidence of MODS in hemorrhagic shock.