Gunshot Wounds - Types, Complications, and Management

Introduction

Gunshot wounds or GSWs are injuries caused due to a piercing bullet or shrapnel into the body with a high potential to cause fatality. The injury induces severe bleeding, intense damage to tissues and organs, fractures, infections, paralysis, and even death. Gunshot wounds to the abdomen and head and neck are prone to more serious complications than injuries to the appendages.

How Many Gunshot Wounds Are Recorded?

GSWs are the second most common cause of injury and death in the United States behind road traffic accidents. Over 80 % of injuries were inflicted by handguns, 8 % by shotguns, and 5 % by rifles. Over 93 % of cases were males aged between 18 and 30 years. Over 83 % of the injuries are self-inflicted and isolated in 89 % of the cases. 55 % of patients report digit injury, 35 % with metacarpal, and 74 % of the injuries occur on the left hand. 45 % of cases were inflicted by BB (ball bearing) or pellet guns and 33 % from handguns out of which 65 % of injuries were accidental while cleaning or loading. Just over 35 % of the patient required surgical intervention.

Over a million injuries occur from interpersonal gun violence resulting in more than 250,000 deaths per annum. 64 % of the deaths were resultant of an assault, 27 % were suicides, and 9 % were accidental. The highest number of deaths from firearm discharge occurs in Brazil, the United States, Mexico, Colombia, Venezuela, Guatemala, and South Africa accounting for over 50 % of the global load. El Salvador, Venezuela, and Guatemala have recorded the highest per capita gun violence. The USA has 10 times the number of gun violence deaths than the next four countries combined in the GDP (gross domestic product) list.

What Are the Types of Gunshot Wounds?

Gunshot wounds are categorized on the basis of the velocity with which it penetrates the body.

Low Velocity

1. Muzzle velocity less than 350 meters per sec.

2. Most handguns (except magnums).

3. Wounds similar to Gustillo-Anderson Type I or II.

Intermediate Velocity

1. Muzzle velocity 350-650 meters per sec.

2. Shotgun blasts:

• Highly variable depending on the distance from the target.

• It can reflect the wounding potential of high-velocity firearms from close range (less than or multiple low-velocity weapons).

• Wound contamination or infection with close-range injuries due to shotgun wadding.

The wounding potential depends on three factors:

• Shot pattern.

• Size of the individual pellets.

• Distance from the target.

High Velocity

• Muzzle velocity more than 600 meters per sec.

• Military assault and hunting rifles.

• Wounds comparable to Gustillo-Anderson Type III regardless of size.

• High risk of infection.

• Secondary to a wide zone of injury and devitalized tissue.

Based on the distance between the firearm and the victim:

• Type 0: Range between 18 to 36 meters with negligible damage.

• Type I: Greater than 6.4 m range where multiple pellets penetrate.

• Type II: 2.7 to 6.4 m range where the risk of amputation stands between 20 and 50 %.

• Type III: Point blank range with wadding lodgement.

What Factors Influence the Severity of Gunshot Wounds?

Factors that affect the severity of gunshot wounds are:

• The velocity of the bullet.

• Mass of the bullet.

• Size of the bullet.

• Drag and retardation.

• Composition and shape of the bullet.

• The extent of penetration.

• The extent of deviation of the bullet.

What Is the Pathology and Mechanism of Gunshot Wounds?

The first bullet hits straight and spins the victim and subsequent bullets penetrate at one or multiple angles causing progressive anatomic structural damage.

To determine the forensics of any gunshot wound first the velocity of the bullet must be considered, which requires the determination of the distance and type of the discharged firearm. The projectile carries kinetic energy which gets transferred to the tissues determining the severity of the damage. The bigger or faster the bullets, the higher the damage. A lodged bullet causes more damage than one which has an exit wound.

Low-velocity bullets (less than 350 meters per sec and less than 230 g) cause less damage, and high-velocity bullets (more than 600 meters per sec and less than 150 g) are highly destructive. A shotgun (366 meters per sec and up to 870 g) is very hazardous at close range carrying a spray of multiple projectiles.

Next, forensics takes into account the zone of penetration, bullet size, and bullet deformity. Furthermore, if the projectile flattens out on impact, it then injures a larger surface area. Deviating from the original path (yawing) after penetration creates a wider area of destruction. Jacketed bullets deform while non-jacketed ones defragment which changes the type of structural damage to the tissues.

Even the thickness and structure of the tissue at the site of penetration affect the extent of the tissue damage.

Other factors affecting the tissue damage from a projectile penetration are:

• Crush and Laceration: Tissue in the path of the bullet is either crushed or lacerated.

• Secondary Missiles: Fragments from metal helmets or from crushed bones can be erratic and unpredictable.

• Cavitation: Permanent and temporary cavity around the path of the projectile through the body.

• Shockwave: Bullets produce a pressure wave that causes remote neural damage, subtle damage in neural tissues, and rapid incapacitating effects.

How Do Gunshot Wounds Present?

The trauma from gunshots is highly variable and presents with extreme interpretations depending on several external and internal factors.

The gunshot victim presents with intense pain and deformity at the site of injury. Some grievously injured patients are admitted unconscious and into hypovolemic shock due to intense blood loss. Devastating effects can arise from bullet penetration into vital organs like the heart, lungs, liver, brain, etc.

Fatality from gunshot wounds results from uncontrolled bleeding, hypoxia from pneumothorax, catastrophic injury to major blood vessels and the heart, and damage to the CNS (central nervous system) or the brain.

Non-fatal wounds may lead to disfigurement, paralysis, limb amputation, or permanent disability.

How to Manage Gunshot Wounds and Victims?

Primary Pre-hospitalization Management:

The first ten minutes after injury are the ‘platinum-10-minutes’. The EMT (emergency medical technician) should triage focussing on stabilizing the patient and the penetration wound. Primary ABCDE survey (airway, breathing, circulation, disability, exposure) should be done by the EMT at the site prepping for immediate transport.

1. The airway must be cleared from obstruction.

2. The patient must be breathing or breathing assistance must be provided.

3. The pulse should be checked, in the absence of which CPR must be initiated.

4. The patient’s ability to move must be assessed, a rigid cervical collar must be used to stabilize the cervical spine.

5. Detect any additional wounds and the presence of exit wounds.

6. Primary control of bleeding by pressure and packing.

7. Providing hemostatic support with pro-coagulant blood products, if necessary.

Hospital Care:

1. Secondary assessment of ABCDE.

2. Establish patient stabilization.

3. Airway management by endotracheal intubation, cricothyroidotomy, or tracheostomy.

4. Bleeding control by balloon catheters, IV coagulation factors, administration of TXA (Tranexamic acid), blood supplements, blood transfusion, and emergent surgery to stop bleeding.

5. Perform regular neurovascular with GCS (Glasgow coma scale) scale and cardiac examination.

6. Rule out and treat compartment syndrome (by fasciotomy) where excess pressure builds up in muscle spaces.

7. Rule out plumbism as bullets are frequently associated with lead toxicity.

8. Examine and document all soft tissue and hard tissue injuries.

9. When the patient stabilizes obtain imaging studies:

• Radiographs can show the location of the lodged bullet, bony involvement, and fracture pattern.

• CT (computed tomography) detect soft tissue injuries and their extent and identifies intra-articular missiles.

• Angiography is essential in high-risk trajectories.

• Any positive imaging findings warrant operative exploration.

10. Fractures require open and closed reduction followed by a bone-specific treatment regimen.

11. The wound must be debrided, irrigated, and disinfected.

12. Surgeries to remove the projectile is done only after primary stabilization is achieved.

13. Surgeries should be done to repair the damaged tissue and prevent further complications.

14. Abdominal GSWs often damage the spleen and splenectomy may be indicated.

Damage Control Surgeries:

In thoracic injuries:

• Swift emergency thoracotomy through the fifth intercostal space.

• Non-anatomical lung resections.

• Lobectomy or pneumonectomy.

• Closure of thoracic wall musculature.

• Temporary thoracic packing in the presence of diffuse bleeding.

• Vascular interventions (ligatures, shunts, or replacement).

• Temporary closure of thoracic wall defects.

In abdominal injuries:

• Massive bleeding: Aortic clamping.

• Bleeding from large vessels: Ligature or bypass.

• Injury to liver parenchyma: Packing or compression.

• Bowel lesions: Staple closure or stoma or no anastomoses.

• Injuries to arteries: Shunt.

• Injuries to veins: Ligature.

• Urinary bladder injury: Catheter or drainage.

• Pancreas injury: Drainage.

• Peritoneal contamination: Lavage followed by laparostomy.

• Abdominal compartment: Laparostomy.

Post-surgical Care

• The dressing area must be cleaned and kept dry.

• Antibiotic and analgesic therapy.

• Elevation of the wound to prevent swelling.

• Regular dressing change.

• Follow-up check-up in case of intense pain or swelling.

• GSWs often warrant longer hospitalization.

• Psychotherapy should be continued as patients often show PTSD (post-traumatic stress disorder) symptoms.

• Avoid sudden movements and exertions.

• Physiotherapy may be required to gain complete normal mobility.

What Is the Prognosis of Gunshot Wounds?

The overall survivability after a GSW stands at 42 % but less than 10 % in case of brain injuries. The prognosis is highly dependent on all the factors that determine the severity. Normal recovery can be expected for approximately 17 % of brain injuries.

What Are the Complications of Gunshot Wounds?

• Pneumothorax.

• Paralysis.

• Compartment syndrome.

• Trauma-induced coagulopathy.

• Coma.

• Multiple organ failure.

• Infection.

• Gangrene.

• PTSD (post-traumatic stress disorder).

• Sepsis.

• Brain damage.

• Disability.

• Lead poisoning.

• Death

Conclusion

Gunshot wounds have been extensively reported all over the world but have been a matter of concern, especially in the US due to liberal gun laws. Mass shootings and accidental injuries to children are being observed quite frequently. Even in developing countries, low-grade and locally manufactured firearms have been rampantly used in interpersonal violence and hooliganism. Stringent firearm laws with grassroots-level surveillance are necessary to reduce the number of victims. Adequate training for EMTs and trauma centers is necessary to bring down mortality.