Upper Extremity Gunshot Wounds

Alex C. Lesiak

John R. Fowler

INTRODUCTION

Mechanism of injury
- Penetration of the upper extremity by a bullet or other missile projected by a firearm
Pathoanatomy
- Small entrance wound and larger exit wound
- Tissue damage occurs due to the passage of the bullet/missile through the tissue, a secondary shock wave, and the cavitation created by the missile.
- The injury can cause blood vessel, bone, muscle, and other soft-tissue damage.
- Extent of injury is determined by the type of firearm, projectile velocity, and projectile mass.
Epidemiology
- 33 599 deaths from firearms in 2014 (63.5% from suicide and 32.6% from homicide)
- 11 101 firearm-related homicides in 2011
- 70% to 80% of firearm homicides and 90% of nonfatal firearm victimizations were committed with a handgun from 1993 to 2011.

EVALUATION

History
- Type of firearm when known
- Timing of injury
- Injuries to other extremities or organ systems
- Associated symptoms
  - Pain
  - Numbness and/or tingling
Physical examination
- Inspection—identify entrance and exit wounds
- Assess for wound contamination (clothing, or other debris that may have entered the wound)
- Detailed neurovascular examination
  - If concern for vascular injury: perform an Allen test and consider use of a doppler machine to evaluate vasculature
- Evaluate bony stability to assess for fracture/dislo cation
Diagnostic data
- Radiographs of the involved area as well as the joint above and below zone of injury
- CT scan or saline injection challenge can assist in determining intra-articular involvement if suspected
- Vascular injury suspected
  - Doppler ultrasonography
  - Arteriography—CTA versus intraoperative angiogram depending on situation and injury
- EMG/nerve conduction velocity cannot distinguish between neuropraxia and transection in the early postinjury period
Classification
- Low velocity (<2 000 ft/s)
- High velocity (>2 000 ft/s)
- Shotgun (Type 0 to Type III)
  - 0: ≥20 yards away and causes very minimal damage
  - I: ≥7 yards and often does not produce major soft-tissue injury due to pellet scatter
  - II: <3 to 7 yards
  - III: <3 yards
    - Types II and III associated with high rates of associated injury
      - ▲ 32% to 48% comminuted fractures
      - ▲ 43% to 59% major soft-tissue disruption
      - ▲ 23% to 45% vascular injury
      - ▲ 21% to 58% peripheral nerve damage

ACUTE MANAGEMENT

Initial trauma evaluation: check airway, breathing, and ciculation (ABCs)
Thorough history and physical examination
Tetanus prophylaxis (Table 58.1)
May consider initial dose of antibiotics (1 g cefazolin)
Initial debridement
- Cleanse wounds with povidone/normal saline and debride in emergency department (E.D).
- Apply sterile dressing
- Splint/cast

TABLE 58.1 Tetanus Prophylaxis Recommendations for Gunshot Wound Patients

Number of Previous Tetanus Vaccinations	Give Td	Give TIG
Uncertain	Yes	Yes
Less than 3	Yes	Yes
3 or more	No	No
Adults and children 7 years of age or older: Td preferred to tetanus toxoid alone. Children less than 7 years of age: diphtheria, tetanus, pertussis (DTP; DT, if pertussis vaccine is contraindicated) is preferred to tetanus toxoid alone. If only three doses of fluid toxoid have been received: give a fourth dose of toxoid, preferably an adsorbed toxoid. If greater than 5 years since last dose: give a booster. Abbreviations: Td, adult-type tetanus and diphtheria toxoid; TIG, tetanus immune globulin.
Adapted from Centers for Disease Control and Prevention. Diptheria, tetanus, and pertussis: recommendations for vaccine use and other preventive measures: recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR Morb Mortal Wkly Rep. 1991;40(RR-10):1-28.