ABSTRACT
Objective To explore pathological changes of the dog lungs after underwater blast injury. Methods Lungs from 37 adult dogs were taken after different underwater blast explosions, and observed with gross examination, light microscopy (LM) and electron microscopy (EM). Results Pulmonary hemorrhage and edema were the main morphological changes. Under LM the alveolus space was seen to be filled with edematous fluid and bloody components. Part of alveolus walls were ruptured and fused into bigger cavities while under EM the mitochondria of alveolar epithelium were vacuolated and some of the capillary predominant endothelium were broken. Hemorrhage was the pathological feature of intestinal tract. Conclusion Severe pulmonary hemorrhage and edema may be the main cause of early death of dogs with underwater blast injury.
ABSTRACT
With the continuous improvement in weaponry, especially explosive weapons, blast injury has become one of the most common war injuries. Underwater blast injury is a common war injury during combat around islands or fighting for beach-head. The wounding effects of underwater blast wave and the characteristics of underblast injury are quite different from that produced in air due to special physical features of water and the underwater pressure. We have investigated the injurious effects of underwater blast wave and its dose-effect relationship. In addition, some protective measures have been tested to prevent or alleviate underwater blast injury. All of these primary results have provided both experimental and theoretical foundation evidence for further researches in respect to the diagnosis, emergency care and protection against underwater blast injury.
ABSTRACT
Objective To study the dose-effects relationship of underwater blast injury. Methods Sixty-one adult mongrel dogs were exposed to underwater explosion of 200g, 500g, and 1 000g of TNT, respectively. The physical parameters of blast wave were recorded by PCB pressure transducers (USA). Survival or death was observed 6 hours after injury. Correspondingly, the relationship between the physical parameters and injury severity was analyzed. Results Twenty-three among 61 dogs died after injury, the mortality rate was 37.70% (23/61). The main reasons of death were severe lung bleeding, lung edema, perforation of gastrointestinal tract, and rupture of liver and spleen. Half lethal (5/10) impulse of underwater blast wave was 337.7?14.3kPa?ms. The impulses resulting in mild, moderate, severe, and critical underwater blast injuries were 140.46?34.2, 199.2?25.2, 247.8?69.6, and 478.7?183.8kPa?ms, respectively. Conclusion The physical parameters were well related to the injury severity in underwater blast. The early main treatment consist of active and effective management of severe lung injuries, perforation of gastrointestinal tract, and rupture of liver and spleen.
ABSTRACT
Objective To compare the propagation speed and physical parameters between underwater blast wave and air blast wave. Methods The physical parameters of blast wave were measured by PCB pressure transducers (USA) during underwater and air explosions of 200g, 500g and 1000g TNT respectively. Consequently, the propagation speed, peak overpressure value, positive duration and impulse of blast wave were analyzed. Results Underwater blast wave was characterized by high propagation speed, high peak overpressure value, great impulse, however, short duration. Compared with air blast wave, the propagation speed of underwater blast wave was 3.70-4.30 times higher than that of air blast wave, the peak overpressure value was 227.15-247.86 times higher, and the impulse was 8.48-11.80 times greater than that of air blast wave. Conclusion Underwater blast wave propagates faster than that air blast wave. Meanwhile, it also peoduces higher peak overpressure value and impulse. This result is helpful for the evaluation of injury severity and treatment of underwater blast injury.
ABSTRACT
Objective To observe effect of the pulmonary injury and the dynamic changes of the blood gas index on the mortality rate of the dogs suffered from underwater blast injury. Methods 38 adult dogs were brought out underwater blast injury by TNT. The dogs that died on the spot were anatomized immediately, while the survivors were anatomized after 6 hours; the blood samples were taken before the explosions, 30min and 6 hours after them to analyze the blood gas index by i-STAT. Results Most of the lung injuries were pulmonary hemorrhage and edema; the positive impulse of the blast wave and the severity of the lung injury were closely related to the mortality rate; the frequency of the respiratory and the blood oxygen and the carbon dioxide pressure can roughly exhibit how severe the lungs were injured. Conclusions The severe hypoxia induced by lung injury is the main cause of the early death; correlation between the severity of the injury and the positive impulse of blast wave is very obvious.
ABSTRACT
Objective To explore the possibility for preventing the underwater blast injuries. Methods Fifty rabbits were divided into two groups: protection and control groups. The animals were placed at the rang of 5.0m to 17.5m far from the explosion point. 0.2kg of TNT Explosives was placed 3 meters under water. Physical parameters of blast wave were measured using pressure transducers. At 6 hours after injury, the mortality rate and morphological alternations were observed. Results The safe devices were shown to be effective against underwater blast injuries. Most of the animals had no or mild pulmonary and intestinal injuries. The whole injury severity was reduced by 2 to 3 degrees with our own made device. Conclusion Our safe device could be used to protect against underwater blast injueirs.