Managing gunshot wounds requires a working knowledge of several mechanisms. Understanding the anatomy and physiology of the body is imperative; the severity of the damage and impacted body structures must be quickly assessed. This assessment also requires knowledge of bullet mechanics as it travels through the human body. Gunshot wounds present different problems for prehospital providers depending on how many bullets made an impact, what part of the body the bullet traveled through, and what type of bullet the firearm ejected.
A bullet from a gun has a certain amount of kinetic energy. Kinetic energy is (0.5)(m)(v2), where m is mass and v is velocity (Woodford, 2018). The more mass and velocity the bullet has, the more kinetic energy it will have. Velocity has a larger effect on kinetic energy than mass; although bullets are small, the sheer velocity they travel at results in large amounts of kinetic energy (Woodford, 2018). This kinetic energy is transferred to the body, which in turn causes injury. This energy transfer displaces tissue as the bullet moves through the body (Stefanopoulos et al, 2014). Pathway expansion occurs when tissue is displaced due to the sonic pressure waves that travel through tissue. This expansion results in cavitation, where tissue is pushed away from the bullet and tissue are compressed (Stefanopoulos et al, 2014). Bullets can fragment upon impact to the body, as well as tumble through tissue (Stefanopoulos et al, 2014).
There are three types of firearm designs: shotguns, rifles, and handguns (Pilbery & Caroline, 2014). Shotguns fire round pellets that are not stabilized in flight by spin (Pilbery & Caroline, 2014). Shotguns will have large entry and exit wounds (Pilbery & Caroline, 2014). Rifles fire a single projectile at very high velocities (Kolata & Chivers, 2018). There are typically small entrance holes and large exit wounds (Kolata & Chivers, 2018). Handguns consist of revolvers and pistols and fire at lower velocities than rifles (Pilbery & Caroline, 2014). Bullet velocities range from low to high velocity (Klatt, 2018). Low-velocity bullets travel at 1,000 feet per second (Klatt, 2018). Medium velocity bullets travel between 1,000 and 2,000 feet per second (Klatt, 2018). High-velocity bullets travel at speeds greater than 2,000 feet per second (Klatt, 2018).
Gunshot wounds can be a result of criminal activity, suicidal intentions, or accidental discharge. Thus, scene safety is imperative when managing gunshot wounds. Approximately sixty-three percent of gunshot wounds are sustained from assaults (Cimino-Fiallos, 2018). Depending on the situation, emergency medical providers need to be aware of their state’s mandatory reporting laws. If abuse or neglect is suspected in a child, elder, or other individuals, emergency medical providers are legally obligated to make a report (Oregon DHS, 2018). Creating a safe scene is the first step to managing gunshot wounds because it ensures all parties are not at risk.
There are several pieces of information to obtain when dealing with gunshot injuries. Determine the type of weapon and its caliber (Pilbery & Caroline, 2014). Also determine what range the weapon was fired at and what type of bullet was used (Pilbery & Caroline, 2014). General management of a gunshot wound revolves around a rapid trauma assessment and ensuring that airway, breathing, and circulation are secure(Pilbery & Caroline, 2014). Remember that controlling life-threatening hemorrhages takes precedence over managing the airway initially (Pilbery & Caroline, 2014). Tourniquet application may be required. Look for powder residue around the wound, as well as entry and exit holes during your assessment (Pilbery & Caroline, 2014). Ensure the patient is treated for shock, and fluid resuscitation is titrated to keep the mean arterial pressure above 60mmHg (Pilbery & Caroline, 2014).
Be aware that penetrating injuries to the chest can cause a tension pneumothorax or sucking chest wound (Pilbery & Caroline, 2014). Both of these require swift intervention; sucking chest wounds must have occlusive dressings placed over them, and a needle decompression must be done to resolve a tension pneumothorax (Pilbery & Caroline, 2014). Hemostatic gauze may be used to pack bleeding wounds in areas where a tourniquet cannot be placed Splint fractures, particularly pelvic fractures, to help control bleeding in the injured area (Pilbery & Caroline, 2014).