View source for 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===
[[File:Bullet.png|thumb]]
====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===
*[[Head Trauma (Main)]]
*[[Penetrating neck trauma]]
*[[Cardiac Trauma]]
**[[Pericardial effusion and tamponade]]
*[[Diaphragm Injury]]
*[[Abdominal Trauma]]
*[[Open Fracture]]
*[[Spinal Trauma (Main)]]

==Evaluation==
[[File:PMC3369416 crg-0006-0243-g03.png|thumb|For intra-articular retained bullet, consider risk of developing [[lead poisoning]].]]
*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<ref>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.</ref>

===Prophylactic Antibiotics===
*Infection after gunshot injury is a rare complication
*No prophylactic antibiotics for:<ref>Hot bullet, Dirty Wound? http://wueverydayebm.blogspot.com/2015/02/hot-bullet-dirty-wound.html</ref>
**Soft tissue gun shot wounds
**Non-operative fractures caused by gun shot wounds 
*Give prophylactic  for:<ref>Simpson, B. M., Wilson, R. H., & Grant, R. E. (2003). Antibiotic therapy in gunshot wound injuries. Clinical orthopaedics and related research, 408, 82-85.</ref>
**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)<ref>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.</ref>

==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<ref>Sandjadi, Javid. Expedited treatment of lower extremity gunshot wounds.</ref>

==See Also==
*[[Missile embolus]]
*[[Wound ballistics]]
*[[Trauma (main)]]

==References==
<references/>

[[Category:Trauma]]