Pathophysiological Process of Gunshot Wounds

"Gun shot wounds are caused when a bullet is shot and enters the body. This bullet can travel over 3,000 miles per hour. The extent of the tissue and organ trauma is determined on ballistics, which is determined by type of gun, velocity and mass". (Gunshot Injuries; Gunshot wounds (GSW) information. (n.d.). Simply owning a firearm puts an individual at risk. A gun in the home is a risk factor for gun-related homicide and suicide as well as unintentional injuries and death. Firearm injury is a can be an expensive injury to care for. "The average direct cost of medical care is about $17,000 per gunshot injury. Annually, lifetime medical costs are estimated at between $2 and $3 billion, with assaults accounting for $1.7 billion or 74% of the total costs. The rate of firearm related injury was seven times higher in males than females. The annual rate of fatal and non-fatal firearm injuries was highest in African American males 20-24." (Cook PJ, Lawrence BA, Ludwig J, Miller TR. 1999;281(5):447-454.)

Gun shot wounds are blunt force, intentional/unintentional cell injuries. They cause chemical mediators to release and do damage to capillary membrane to cause inflammation and damages membranes. Antibodies can interfere with cellular communication and cause damage.

According to Huether, S. E., McCance, K. L., & Parkinson, C. (2008), cellular injury caused by a gun shot is penetrating trauma. This is a mechanical injury to the body resulting in tearing, shearing and crushing of tissues. The placement and projectile path is the determinant of the injury These injuries can include severe bleeding, damage to tissues and organs, broken bones, wound infection and paralysis. Physical signs and symptoms will vary due to size of bullet and area affected. Gunshot wounds are most commonly to the small bowel, colon, and liver. Entrance wounds present with elastic tissue contraction around the wound. If the gun was in contact with the skin, the physician would see burn marks around the wound. Close range wounds have soot deposited around the wound. Long range wounds usually see an "abrasion collar" around the bullet hole. Exit wounds are not consistently larger than entrance wounds, however the skin is enverted outwards. Exit wounds do not have abrasion collars, soot or tattooing Gunshot wounds are particularly prone to anaerobic infection, especially tetanus and gas gangrene. "Medical staff should ensure tetanus cover is up-to-date, and intravenous antibiotic prophylaxis of 24-48 hours' duration is usual following fractures caused by high-velocity weapons or shotguns". (Antibiotic Therapy in Gunshot Wound Injuries.

Clinical Orthopaedics and Related Research,408, 82-85). "In the first 10 min after injury (the “platinum 10 minutes”), the victims are in danger of the typical, avoidable immediately life-threatening complications" (Wounded in action: the platinum ten minutes and the golden hour 2014 Sep; (788):14-5) Elapsed time between the trauma and the presentation greater than 6 hours, presence of shock upon admission to the hospital, surgery lasting more than 6 hours, PATI (penetrating abdominal trauma index) score higher than 25, presence of more than 2 injured intra-abdominal organs, presence of more than 2 extra-abdominally injured organs and administration of multiple blood transfusions are all risk factors that increase the complication rates in penetrating abdominal traumas.

As protocol, establishing airway, breathing and circulation are first and foremost. History and physical exam are usually brief and oriented to the injury. Laboratory tests are rarely ordered in the acute treatment of gun shot wounds. Hemoglobin and Hematocrit values and arterial blood gas determinations offer the most useful information, however, they are not typically ordered until the patient is stable. Computed Tomography is rapidly evolving as a primary diagnostic tool. E-FAST is a rapid bedside ultrasound examination performed by surgeons, emergency physicians and certain paramedics as a screening test for blood around the heart (pericardial effusion) or abdominal organs (hemoperitoneum) after trauma. These test can improve efficiency and expeditious treatment of the patient. They will enable the physician to determine location, severity and what standards of care must be taken.

While treating patients with acute wounds from gun shots, ABC's should be protocol. Injuries must be treated expeditiously as every hour counts to avoid more extension cellular injury and infection. There are new imaging tests that can be utilized at the bedside to determine area and severity and determine standard of care.