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The Experimental Study On The Characteristics Of Wound Tract And Its Systemic Influences After Gunshot Wound In A Simulated War Environment At High Altitude

Posted on:2006-02-15Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z M YinFull Text:PDF
GTID:1104360155473962Subject:Surgery
Abstract/Summary:PDF Full Text Request
Because of poor understanding to the plateau firearm wound, for high altitude war wound, the therapeutic principle at low level altitude for war wound has been used in the past, which delayed the best treatment time, resulted in a high infection rate, disability rate and death rate. The issues of border dispute and long lasting separation movement makes the high altitude region may be the hot-place of future war in our country. So the research on the characteristics of firearm wound at high altitude and their management principle and echelon treatment protocol is badly in need. Up to now, there are no related research at home and abroad. For this, we studied the characteristics of wound track and the its influences on body after gunshot wound in the 3 658m high altitude, and in a simulated wartime environment. The objective of the present study is to provide the theoretical basis and experiment evidence for making therapeutic principle and echelon treatment protocol for war wound management at high altitude. Main research contents and methods The experiments were divided into two parts. Part I: Study on the pathophysiological characteristics of wound tract after gunshot wound of pig limbs at cold high altitude in a normal or war environment. 24 pigs, divided into normal environment low altitude group(PP, n=8), normal environment high altitude (GP, n=8),and war environment high altitude group(GZ, n=8). The pigs at awake status were shot at posterior limbs in 20m distance with 7.62mm bullet. The tissue injury, inflammation response, infection, energy metabolism and blood perfusion in muscular tissues of the wound tract were measured at different time points. Part II: Study on the systemic influences after gunshot wound of pig limbs at high altitude in a normal or war environment. The groups and animal model were the same as Part I. The systemic stress reaction, inflammation response, metabolism, lipid peroxidation and indexes reflecting important organ function in plasma were measured at different time points. Main results and conclusions 1. Clarified the pathophysiological characteristics of wound tract after gunshot wound of pig limbs in a normal environment at high and cold altitude. The result indicated that the bullet speed in the plateau was quicker than the low altitude region, the bullet energy released to the tissue was also higher than that in plain. Compared with PP group, the scope of wound tract was larger, the tissue blood perfusion was lower, the injury degree of tissue was more heavy. The storage of energy and enzyme vitality in muscular tissue of wound tract was lower, and the disorder of energy metabolism in wound tissue was heavier than PP group. But the inflammation response and tissue edema of the wound tract in GP group was lighter than the PP group. The occurrenc of wound infection was postponed at 48-72 hours after wound, and the critical quantity of the bacteria to cause infection was 107 cfu/gram wet-tissue. 2. Clarified the systemic influences of gunshot wound in pig limbs in normal environment at high altitude. Compared with PP group, the stress reaction after gunshot in normal environment at high altitude was more heavy and lasted for a longer time. IL-1β,TNFα, NO in plasma was increased in the early stage and IL-4, IL-10 was increased in late stage. The anti-oxidation ability was significantly decreased after gunshot. The principle of the change of the blood sugar(BS), lactic acid(LA), free fatty acids(FFA),and the total free amino acid(TAA) in plasma was similar to the PP group, but more severe and lasting for a longer time. The slight hypomagnesemia was found at 6h-3d after wound, the hyponatremia and hypochloraemia was found at 7d after wound. After gunshot wound, the pigs in GP group had a higher energy expenditure which lasted a longer time, the material storage and the enzyme vitality of energy metabolism in normal muscular tissue were lower than PP group. After injury the cardiac output was decreased, the respiratory alkalosis and metabolic acidosis was appeared. The hepatic enzymogram and the kidney function changes were also heavier than that in the plain region. 3. Clarified the pathophysiological characteristics of wound tract after gunshot wound of pig limbs in the plateau, high cold and war environment.As compared to GP group, the anti-oxidation ability and oxygen-derived free radicals clearance abilities of the muscular tissue in GZ group were lightly decrease before gunshot wound. As compared with the GP group, the anti-oxidation and tissue damage in the muscular tissue of wound tract in war environment at high altitude were significantly decrease after gunshot wound, the inflammatory response and tissue edema of the wound tract are slightly severe than GP group. The infection time of wound tract was at 24-36 hours, and the critical quantity of the bacteria to cause infection was 106 cfu/gram wet-tissue. The formation of the thrombosis in the wound tract tissue was earlier and more severe than GP group. The storage of energy and enzyme vitality in muscular tissue of wound tract was lower than GP group, and the energy metabolism disorder in wound tract tissue was heavier than GP group. 4. Clarified the systemic influences of gunshot wound of the pig limbs in the plateau , high cold and war environment As compared to GP group, the anti-oxidation ability of animal in GZ group were decreased to some extent, and the FFA and TAA were increased, and the stress reaction, the inflammation response, the hypoglycemia and hyperlactacidemia were appeared before gunshot wound. At the same time the activity of LDH, CK and Na+-K+-ATPase in the normal muscular tissue were decreased, and the muscle glycogen and Pi3+ had a little decreased. After gunshot wound, the stress reaction was very strong, and lasted for a longer time. IL-1β,TNFα, NO in plasma appeared in the early stage and IL-4, IL-10 in plasma appeared in the late stage were significantly higher than the GP group, and lasting time was longer than the GP group. The plasma endotoxin appeared earlier and higher than the GP group. As compared with the GP group, the anti-oxidation ability of the body was significantly decreased, and the lipid peroxidation was severe, and the blood was in a hypercoagulabale state after gunshot wound. The level of BS, LA, FFA and TAA in plasma were higher than the GP group, and kept higher level more than 7d after injury. The severe hypomagnesemia was found at 6h-3d after wound, and the severe hyponatremia and hypochloraemia were found at 5d-14d after wound. The pigs in GZ group had a higher energy expenditure and kept a longer time after injury, the material storage and the enzyme vitality of energy metabolism in normal muscular tissue were lower than the GP group, and the energymetabolism disorder in the tissue appeared earlier than the GP group. Serious respiratory alkalosis and hypoxemia existed after wound. The hepatic enzymogram and the kidney function were damaged heavier than that in GP group. In conclusion, the results of all the GP and PP groups in the present study suggested that the plateau environment could cause the pathophysiological change of the multiple organs of whole body. The function of the vital organs are lower than that in lower altitude region. Based on this, the homeostasis could be easily disturbed and the organ function could be injured after gunshot. But the inflammation response and the tissue edema of the wound tract was attenuated, the time of the wound tract infection was delayed. Under the influence of the plateau and war environment, pigs in the GZ group showed much more changes in the partial tissue and the multiple organs before injury. After injury, the changes was more severe and more permanent, and the homeostasis and the organ function disorder were more apparent.
Keywords/Search Tags:Plateau, Bullet wound, War wound, Firearm wound, Cold, Lipid peroxidation, Wartime, Inflammatory response, Infection, Hepatic enzymogram, Stress reaction, Inflammatory mediator, Endotoxin, Cardiac function, Kidney function, Anti-oxidation ability
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