Establishment of the swine model of abdominal war injury coupled with seawater immersion

Abstract

Objective To establish the stable and reproducible swine model of abdominal war injury coupled with seawater immersion. Methods Twenty Obama miniature swine were randomly divided into the seawater group and the ground group, each consisting of 10 swine. The animals in the seawater group were injured by the home-made type 81-1 rifle shot at the McIntosh point of the left abdomen from a distance of 10 m, when they were half floated in the seawater. They were salvaged following 60 min of seawater immersion. The animals in the ground group were injured in the same way, but without seawater immersion. With the salvage time out of water as the reference time point (60-min seawater immersion for the animals of the seawater group and also the same length of time for the animals of the ground group), the body temperature, heart rate, respiration and blood pressure indexes in 120 min were detected for the animals of the 2 groups, and the death rate of the 2 groups was also statistically analyzed. One hundred and twenty minutes after salvage from the water, exploratory laparotomy was performed to detect the injuries of the abdominal organs in animals of the 2 groups. Then, liver, lung and intestine samples were collected through laparotomy, and pathological changes were observed under light microscopy. Results One hundred and twenty minutes after salvage, respiratory frequency of the 2 groups all increased with the extension of time, and statistical significance could be noted when comparisons were made between the same time points(P<0.05). Heart rate of the seawater group was first elevated, and then was decreased, while no significant changes in the ground group was noticed, and no statistical significance could be seen in heart rate when comparisons were made between the 2 groups(P<0.05). Body temperature of the seawater group all increased with the extension of time, while no significant changes could be seen in the ground group, and statistical significance could be found in body temperature when comparisons were made between the same time points(P<0.05). Blood pressure of the seawater group first increased and then decreased with the extension of time, while no significant changes could be seen in the ground group, and no statistical significance could be seen in blood pressure. No significant changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) could be noted for both groups(P<0.05). No statistical significance could be seen in the differences of organ injury and the number of intestinal perforation, when comparisons were made between the 2 groups(P<0.05). From the analysis of the injured intestine, statistical significance could be observed, when comparisons were made in the diameters of the intestinal outlet and intestinal inlet for the 2 groups(P<0.05). Mortality rates of the seawater group and the ground group were respectively 30% and 10%, and no statistical significance could be noticed, when comparisons were made between the 2 groups(P<0.05). Various pathological organ injury data indicated that inflammation and edema levels of the seawater group were obvious severer than those of the ground group. Conclusions The swine model of abdominal gunshot injury coupled with seawater immersion realistically simulated the pattern of gunshot injury encountered in littoral war, which fully mixed with the two factors (seawater immersion and gunshot injury), and was applicable to related researches on the medical treatment of abdominal war injury encountered in the littoral war. Key words: Gunshot injury; Littoral; Establishment of the model