Gun shot wounds

Background

  • Bullets
    • Composed of a full or partial metal "jacket" around a lead alloy core
    • Shape depends on caliber and tip type (pointed, flat, hollow, soft)
  • General caliber classification
    • Small (.22, .25)
    • Medium (.32, .38, .357, 9mm)
    • Large (.40, .41, .44, .45, .50)
  • Common shotgun gauges
    • 12-gauge = bore diameter of .729 inches
    • 20-gauge = .615 inches
  • Shotgun pellets, small to large
    • Birdshot (shotshells) - many small pellets, large kill spread
    • Buckshot - fewer but larger pellets
    • Slug, sabots - single large solid slug

Types

Bullet.png

High Velocity Bullets

  • Examples: .223 or 30/06 Springfield
  • Very high kinetic energy
  • Little deformity when fired
  • Cavitation is principle mechanism of destruction, the dissipation of energy radially away from the bullet as it travels through tissue
  • Large zone of tissue injury even away from tract

Low Velocity Bullets

  • Examples: .22 long rifle or .45 pistol
  • Relatively low kinetic energy
  • Deform from friction
  • Crash injury is principle mechanism of damage given projectile tumbling and fragmentation

Shotgun

  • Very high kinetic energy at close range
  • Shells contain several to several hundred hundred pellets
  • Spread of pellets and rapid energy transfer makes these weapons dangerous at close range

Clinical Features

  • Assess for number of wounds to help determine if projectile may still present in body
    • Exit wound may not follow logical trajectory
    • Strongly consider not documenting "entrance" vs. "exit" given medicolegal implications if not completely sure
  • Entrance wound (typical features)
    • Round, punched out hole
    • Marginal abrasion or abrasion ring
    • +/- fouling (soot)
    • +/- stippling (punctate abrasions from gunpowder impact)
  • Exit wound (typical features)
    • Usually larger (except head)
    • Wound edges may be reapproximated
    • No marginal abrasion
    • Slit-like, stellate, circular
    • Irregular due to loss of kinetic energy, bullet deformation, yaw
  • Range of fire
    • Contact (< 12 inches) → fouling/soot, muzzle stamp (tight contact)
    • Intermediate (2.5-3.5 feet) → +/- fouling, stippling
    • Distant (>3.5 feet) → wound only
  • Shotgun extrance wounds
    • Marginal abrasion, fouling, stippling
    • Plastic wad may be found in body if range <5-10 feet
    • Close range (<12 inches) may have ~1 inch diameter single hole with fouling
    • 3 feet - round hole, scalloped edges, stippling
    • 4 feet - round hole, scalloping, satellites
    • Distant (>10 feet) - pellet spread

Region Specific Information

Evaluation

  • ATLS/FAST/Trauma Labs
  • CT Scan as needed depending on location
  • X-ray if bony injury suspected
  • CTA if vascular injury suspected

Management

  • Trauma consult depending on location and extent of wound
  • Ortho consult for bony injuries
  • Neuro/OMF/ENT as needed
  • Removal if intraarticular, with case reports of lead toxicity[1]

Prophylactic Antibiotics

  • Infection after gunshot injury is a rare complication
  • No prophylactic antibiotics for:[2]
    • Soft tissue gun shot wounds
    • Non-operative fractures caused by gun shot wounds
  • Give prophylactic for:[3]
    • Intra-articular fracture (any type of gun shot wound)
    • Fractures caused by high-velocity weapons or shotguns
    • Penetration through contaminated hollow viscous (passage through bowel)[4]

Disposition

  • To OR if significant injuries
  • Admission/Obs for less concerning injuries
  • Minor injuries may be discharged
  • GSW Protocol allows lower extremity wounds to be discharged from ED after 9 hours without invasive imaging if they have normal ABIs[5]

See Also

References

  1. Lu K et al. Approach to Management of Intravascular Missile Emboli: Review of the Literature and Case Report. West J Emerg Med. 2015 Jul; 16(4): 489–496.
  2. Hot bullet, Dirty Wound? http://wueverydayebm.blogspot.com/2015/02/hot-bullet-dirty-wound.html
  3. Simpson, B. M., Wilson, R. H., & Grant, R. E. (2003). Antibiotic therapy in gunshot wound injuries. Clinical orthopaedics and related research, 408, 82-85.
  4. Lu K et al. Approach to Management of Intravascular Missile Emboli: Review of the Literature and Case Report. West J Emerg Med. 2015 Jul; 16(4): 489–496.
  5. Sandjadi, Javid. Expedited treatment of lower extremity gunshot wounds.