Morphological changes in lung tissue in case of blunt abdominal trauma, massive blood loss, and ischemia-reperfusion of the limb
Authors: Fedoseeva O. V. 
Published: June 2021

Introduction. Combined trauma remains an urgent problem in medicine because it is the leading cause of death in victims of working age. Among the main causes of death in the prehospital stage among the injured is massive blood loss and further development of organ dysfunction, including lung. In recent years, significant progress has been made in providing assistance to victims of massive blood loss, but the impact of ischemia-reperfusion of the extremities in the development of systemic changes remains unresolved.Objective of the research: to study morphological changes in lung tissue in the model of combined abdominal trauma, massive blood loss and ischemia - reperfusion of the lower extremities.Materials and methods. To conduct the experimental study used 80 adult white male rats of the Wistar line weighing 190-220 g. The experimental animals were in the standard diet of vivarium.The experimental animals were divided into the following groups: control and 3 experimental (8 animals in each group). In animals of the first experimental group under thiopental-sodium disorder (40 mg kg-1) proximal to the lower limbs was imposed hemostatic plait for a period of 120 min. In the second experimental group, a combined injury of the abdominal organs was simulated by applying two metered blows to the abdominal area; hypovolemic shock was modeled by blood flow from 20 to 22% of circulating blood volume from the femoral vessels. In the third experimental group, the combined injury of the abdominal organs, massive blood loss and reperfusion of the extremities was modeled. Animals in the control group were administered only in anesthesia.The animals of the experimental groups were removed from the experiment under conditions of thiopental sodium anesthesia by total blood flow from the heart after 1, 3 and 7 days after modeling trauma. Pulmonary tissue was collected for the study.For histological examination, the lower lobe of the right lung was removed, which was fixed in 10% formalin solution, after which the macrodrug was compacted in paraffin. Sections were obtained on a microtome followed by staining with hematoxylin eosin. After fixation of sections on individual slides studied the structure of the lungs in the study groups. Used equipment: LOMO Biolam I microscope; system of digital display of images of histological preparations. Particular attention in the study was paid to changes in the parenchyma and the main structural components of the lungs.Results and Discussion. In the simulation of ischemia-reperfusion in the early periods in animals, changes were visualized from the first day in the form of endothelial lesions, increased perivascular edema, and cellular infiltration with signs of acute inflammation up to 3 days of experiment and formation of dyslectases up to 7 days of the experiment. When modeling closed abdominal trauma and massive blood loss in the lungs, structural changes increase from the first day of the experiment in the form of a sharp decrease in blood supply, lymphoplasmic infiltration of the stroma of the interalveolar septa, and the appearance of segmental leukocytes from 1 day of the experiment. After 3 days in the lumen of the vessels appear manifestations of erythrocyte aggregation and the formation of small parietal thrombi and pronounced dystrophic-necrotic changes in pneumocytes. After 7 days of the experiment, the acute manifestations are somewhat reduced, but there are pronounced dystrophic changes of the epithelium and pronounced lympho-plasmacytic infiltration of the stroma of the interalveolar septa, dystelectasis.Closed abdominal trauma, massive blood loss, and ischemic-reperfusion syndrome in the early periods in the lungs were manifested by pronounced structural changes: thickening of the interalveolar septa due to intensive infiltration of lymphoplasmocytes, especially on day 3 of the experiment with a moderate inflammatory reaction. After 7 days of the experiment, the cellular and inflammatory infiltration of the stroma and dystrophic manifestations decreased slightly. The obtained data indicate the development of systemic changes in experimental animals and a significant increase in the possibility of developing multiple organ failure syndromes. This indicates the need for further study of the effects of reperfusion in the context of combined trauma and, accordingly, the development of effective means of correction.Conclusions. Ischemia-reperfusion of the extremities alone and in combination with other injuries causes changes in lung tissue from the first day, progression to the third day of observation and a slight decrease in manifestations up to 7 days of the experiment. The results of the study suggest that ischemia-reperfusion is an important traumatic component in combined trauma.