Effect of missile velocity on the pathophysiology of injuries.

The investigations were carried out on sheep weighing 55 kg on the average. Under general anaesthesia both hind legs were shot through from a distance of 15 m separately with missiles of high or medium initial velocity. For producing haemorrhagic shock in some animals rapid bloodletting was done with removal of 45% of the circulating blood volume. At definite time intervals the serum levels of adrenaline, noradrenaline, glucose, free fatty acids and insulin were determined in the arterial blood. The heart rate, pressure in the aorta and central venous pressure were measured. Following shots with high velocity missiles the observations were as follows: 1) signs of shock appeared earlier and were more dramatic, 2) the extent of exit wound was on the average threefold as large, 3) haemodynamic disturbances developed earlier, increased more sharply and were much greater, 4) the rise of catecholamines level was much more violent reaching many times higher values and persisting longer, 5) changes or glucose, insulin, free fatty acids and insulin were much more pronounced, developed earlier, and regressed after a longer time than after injuries caused by missiles of medium initial velocity.