冲击波负压对大鼠肺致伤效应的初步观察

观察了不同的冲击波负压峰值对大鼠肺的影响。各种条件下的冲击波负压值可由负压发生装置来模拟调节,这种装置可满足化爆、核爆和爆炸性减压下负压参数的一般要求,参数稳定,重复性好。冲击波负压峰值范围为-13～-90kPa,下降时间为1～90ms,持续时间为14～2 000ms。6组Wistar系大鼠,分别暴露在-47.2～-84.0kPa的冲击波负压环境中,伤后立即解剖动物,重点观察肺伤情。实验结果显示,在上述冲击波负压环境中,肺可出现从无伤至极重度伤;出血、充血以及肺表面压痕酷似肺冲击伤的病理表现。随着冲击波负压峰值的变化,各组肺伤情亦随着变化,冲击波负压峰值(△P)和减压倍数(P_i/P_a)分别与肺出血面积和动物死亡率相关显著或非常显著。本实验提示,一定条件下的冲击波负压具有明显的致伤作用,且伤情变化范围与超压所致肺伤情变化范围相同,超压和冲击波负压在一定条件下可通过伤情指标等效。

PRELIMINARY OBSERVATION OF THE UNDERPRESSURE EFFECTS ON RAT LUNGS

The experiment was designed to clarify the effects of peak underpressure on the lungs. An underpressure generator was established to simulate various underpressure parameters in some environments, such as chemical explosion, nuclear explosion and explosive decompression. The peak underpressure, the time required to decrease to the peak underpressure and the duration of the underpressure ranged from -13 to -90 kPa, 1 to 90 ms and 14 to 2000 ms respectively. These parameters were well repeatable. Fifty rats were exposed to the underpressure at the mean peak level of-47.2 , -58.6, -65.8 , -76.1 and -84.0 kPa respectively. The other ten rats served as the control group. All animals were sacrificed within 30 minutes after exposure. The changes of the lungs, weight of the wet lungs and the bleeding surface area of the lungs were observed. The results showed that the lung injury varied from mild to extremely severe degrees, and manifested as congestion, bleeding, edema and appearance of strip markings on the surface of the lungs, exactly like those found in the lung blast injury. The bleeding surface area of the lung and the death rate of the rats were positively related to the peak underpressure values (AP) and decompression ratio (Pi/ Pa). It is concluded that the underpressure as a component of the blast wave has definite injurious effect on the lungs, and the Pi / Pa may be an important index for evaluating the effect of the overpressure of the blast wave equivalent to that of the underpressure on the lungs.