Establishment of a model of explosive open chest injury and seawater immersion and study on results of early treatment

Objective: To establish a model of explosive chest injury and seawater immersion and study on results of early treatment. Methods: Twenty health dogs were divided into two groups: explosive chest injury group and simple open pneumothorax group. A explosive model of open chest injury was established with lower dose of TNT. The animals in both groups were immersed into seawater after chest injury. Blood samples were taken at eight different time intervals for assessing blood gas, serum osmotic pressure and serum electrolytes. The hemodynamic and respiratory changes were recorded. At the end of study lung was harvested for pathologic examination. Results: Post trauma condition in explosive chest injury group was more serious than that in simple open pneumothorax group. After acute treatment survival time in both groups were significantly longer, especically in simple open pneumothorax group. Conclusion: The results of this study indicates that the explosive model of chest injury is practicable and can be repeated well. The physiopathologic changes of hemodynamic and respiratory system are similar to that of humen chest injury. These risky factors appear to be associated with severe serum normal saline metablism imbalance and higher osmotic pressure which resulting from seawater immersion in both groups. But the higher risky in explosive group may related to severe acute lung injury.