Gunshot Wounds Of Lower Limb Soft Tissue Induced Far-reaching Effects Of Pig

BackgroundWith the development of military technology, significantly enhance the bullet woundforce, the ratio of bullet wound in the wounded limb gradually increased. Besides thedirect ballistic injury caused by bullets, injury of distant organs may also occur, that isfar-reaching effect. Research suggests that the gunshot wound caused by far-reaching effect ismainly due to the body’s stress response caused[1]. In recent years, although the injurymechanism of far-reaching effect had some reports, the characteristics of damage in thenon-adjacent distant organs caused by primary injury, especially the characteristics ofdamage and progress on the examination of image has not been investigated. In recentyears, on the basis of the experiment in this group always study, in order to furtherobserve the lower limb soft tissue bullets through wound induced by physiological andbiochemical changes and lung injury; observation before shooting injury caused by drugintervention (intravenous drip and0.9%sodium chloride injection100ml, vitamin C 2.0mg, dexamethasone2.0mg, carbazochrome10mg) for lower limb soft tissue throughremote organs lung injury and the effect of screening for the future prevention and earlydiagnosis of limb bullet injury to the lungs as far as valid indicators of effect damage. Thisstudy intends to adopt64-slice CT to analysis of lower limb soft tissue bullets wound earlylung injury as far as efect imaging changes and characteristics. At the same time, bloodplasma endothelin (ET) and corticosteroid (COR) were in examined by the biochemicalmethods at different time point, clear these indicators change and damage the relationshipbetween the shootings, and find the mechanism of far-reaching effect. To effectivelymonitor, prevent and reduce the lower limb soft tissue bullets through injury caused bylung injury as far as effect to provide reliable experimental basis.ObjectivesTo explore the64-slice CT manifestation changes in far-reaching effects caused bygunshot on pig lower limb soft tissue, and to discuss characteristics of lung injury and themechanism of far-reaching effect, and to observe the protecting effect of the use ofanti-injury drug on lung remote effect injury of gunshot wound in pig lower limb softtissue, in order to provide the theory basis for the diagnosis and treatment, to study themechanism and prevention of remote effect injury.MethodsPart1. Gunshot wounds of lower limb soft tissue induced far-reaching effect of pig.Select12plain pig, pig aged from9to12months, weight between45～55kg,provided by the Fourth Military Medical University Experimental Animal Center. Afteranimal anesthesia, use the domestically produced81-1type semi-automatic rifle and thebullet diameter is7.62mm to shot pig lower limb at1.0cm front of femoral artery outsideof50cm distance．Before and after injury, chest VCT scan was performed, and thecharacteristics of VCT images and pathological results were analyzed. At the same time,blood plasma ET and COR concentrations were checked before and after shooting. After the operation, put to death animals with10%potassium chloride10mg heart injections,immediate thoracotomy, cut big blood vessel bleeding, complete remove lung, part of thelung specimens in the formalin fixed, part of the lung specimens of imaging showed areasof organization for pathologic examination.Part2. The protection of anti-injury drugs to the far-reaching effects induced bygunshot wounds24pigs were randomly divided into protective and experimental group. In protectivegroup, anti-injury drugs (intravenous drip and0.9%sodium chloride injection100ml,vitamin C2.0mg, dexamethasone2mg, carbazochrome10mg) were given3daysbefore gunshot. In experimental group, the same amount of sodium chloride injection wasgiven. After animal anesthesia, the domestical81-1type semi-automatic rifle with7.62mm bullet was used to shot pig lower limb soft tissue at1.0cm front of femoral arteryoutside of50cm distance．Before and after injury, chest VCT scan was performed, and thecharacteristics of VCT images and pathological results were analyzed. At the same time,blood plasma ET and COR concentrations were checked before and after shooting. Afterthe operation, put to death animals and use the methods with the experimental one topathologic examination.Results1. Gunshot on pig lower limb soft tissue can cause lung far-reaching injury. VCT scanshowed different size and extent of sheet or cord-like high-density shadow with theobscure edge and nonuniform density. The reduction in light transmission andground-glass change were found in the surrounding lung. All animals had noatelectasis and hemopneumothorax. Pulmonary vascular and bronchial diameter hadno significant changes．2. After gunshot, dark red or bright red patchy and large areas of hemorrhagicmanifestations were found in pig lung specimens by naked eye; visceral pleura andlung rupture were not observed. After use of anti-injury drug before gunshot, scattereddark red or bright red patchy and small areas of hemorrhagic manifestations were found in pig lung specimens by naked eye. Under microscope find that expansionpulmonary microvascular, bleeding, broken capillaries, alveolar hemorrhage andedema. Meanwhile, honeycomb change occurred in thickening, congestive andhydropic alveolar septa. Alveolar cavity filled with a large number of red blood cells,cellulose-like substance and leukocyte. After use of anti-injury drug before gunshot,little alveolar hemorrhage, cellulose-like substances and inflammatory exudate couldbe found under microscope.3. After gunshot, blood plasma ET and COR levels increased significantly after theshooting, especially at10minutes after the shooting(P<0.05)．After use of anti-injurydrug before gunshot, blood plasma ET level has no statistical differences(P>0.05),blood plasma COR level increased at10minutes after the shooting, it has statisticaldifferences(P<0.05)．Conclusion1. Lung remote effects can be induced by shooting at pig lower limb soft tissue, whichcan be discovered by chest VCT performance and pathology manifestation. And VCTperformance and pathology manifestation were consistent with each other.2. Pathology observation and biochemical research suggests that stress response may beinvolved in the early occurrence of the remote effects.3. Use of anti-injury drug before shooting could reduce lung remote effects induced byshooting at pig lower limb soft tissue.