Projectile injuries commonly present as gunshot wounds or fragmentation injuries. All missiles destroy tissue through tearing a hole called the permanent cavity. Injury also occurs by displacing, or stretching, tissue away from the projectile path much the way water moves away from a rock thrown in it; it’s a temporary cavitation effect. Can they be treated with the simple supplies available in an austere situation?
The Mechanics of a Projectile Injury
There has been much research trying to predict the degree of injury caused by the temporary cavity beyond the obvious permanent cavity. It is clear that tissue which has been displaced due to the temporary cavity can be severely damaged. Due to many various factors, such as bullet type, bullet velocity, bullet weight, firearm, intervening debris, type of tissue struck, bullet yaw or fragmentation, etc., then prediction of the degree of tissue destruction beyond the permanent cavity is exceedingly difficult. Therefore the wound itself, not the type of firearm or bullet, is what is treated. Most explosive fragments are not streamlined, do not have spin stability as a rifle bullet does, and are usually less dense than bullets. All these factors cause them to lose velocity much more rapidly than bullets, and typically this results in less tissue penetration compared to bullets and with less temporary cavitation effects.
Most projectiles follow a relatively straight course from entrance to exit wound or point of termination within the body. This allows for some anticipation of possible injuries. Debridement (removal) of obviously dead tissue would be indicated and looking for evidence of bowel, vascular, or neurological injury should be entertained depending on the course of the missile. Aggressive attempts at removing the missile is not indicated in most injuries, due to risks of worsening the injuries (unlike cowboy movies, where removal of the bullet assures that the patient will survive; this is absolute hogwash and should not be performed).
Can a Projectile Injury be Treated in an Austere Environment?
With extremity injuries, constricting items such as rings should be removed because swelling from the injury may occur and cause the jewelry to dig into tissue causing further injury. Nerve injury may be anticipated if there is loss of certain muscular functions or touch sensation. Nerve repair in primitive environments is not usually possible, and would usually need operative repair. A cold extremity which is pulseless (no radial artery, dorsalis pedis or posterior tibial pulse) would suggest the possibility of a major vascular injury. which is usually not a reasonably treated injury in a primitive environment. That would usually need operative repair to prevent death of the extremity.
Injuries involving the abdomen (from whatever cause) with exposed bowel are not reasonably treated in a primitive environment; a moist clean dressing should be applied until operative repair is available. An abdomen which is rigid (has tightly contracted abdominal muscles) or has generalized severe abdominal tenderness (peritoneal signs) are also suggestions of a severe intra-abdominal process most likely needing surgery and not well managed in primitive settings.
All bleeding wounds may be initially treated with pressure which can stop bleeding from almost any vascular injury if applied for a long enough period of time and with adequate force. If application of pressure fails to offer bleeding control, inspection of the wound to look for a bleeding vessel may be performed. Visibility of the vessel causing the bleeding may be difficult due to pooling of blood within the wound. Clearing the wound of this blood pool with gauze may be needed or application of an inflated blood pressure cuff or tourniquet closer to the trunk may decrease blood flow enough to allow visualization of the bleeding vessel. The vessel may be tied off with a suture (ligated), with the understanding that tied large arteries can result in limb loss. Blind application of sutures or hemostats is a treatment of last resort, since it may worsen injury to a larger artery which might have stopped with simple pressure, and runs the risk of injuring additional structures such as nerves.
F250Doc is a board certified surgeon who seeks to help others prepare for a variety of situations.