The immediate circulatory response to high-velocity missiles.

The immediate hemodynamic response to a high-velocity missile wound was studied in the hind legs of dogs. A spherical missile of constant mass and velocity was used. The immediate effect after the shot was a marked transient peak flow, which may be due to the effects of the pressure wave on the vascular bed, with a release of constrictor tone. The subsequent more constant increase of blood flow in the traumatized leg is of the same character as that seen following extensive soft-tissue contusion trauma. In addition to these local changes there was also a generalized effect with decreased blood pressure without a compensating increase in hear rate. This may be explained by the specific character of the trauma that a high-velocity missile produces.