EMPOWERING PHYSICIANS WITH EVIDENCE-BASED CONTENT
 

Home > Browse Topics

<< Ballistic Injuries In The Emergency Department (Trauma CME)

Management Of Gunshot Wounds To The Extremities

The most important factors to consider with a firearm injury to the extremities are the possibility of vascular and nerve injuries, compartment syndrome, fractures and knowledge of the type of weapon used. Artery and nerve injuries are the major causes of mortality and long-term morbidity in extremity gunshot wounds.108

Although low-velocity injuries from handguns account for the majority of extremity injures in the civilian population, high-velocity wounds and shotgun wounds have the greatest potential for devastating injury, largely because they have a higher percentage of kinetic energy transference, have a higher degree of wound contamination, have a higher risk for compartment syndrome, and more often have associated comminuted fractures with devitalized bony fragments.109,119 Shotgun injuries, overall, have been found to have twice the mortality rate of rifle or handgun wounds.

Wounds to the shoulder have been found to represent 9% of upper extremity gunshot wounds. Approximately 15% of these wounds are associated with a vascular injury and up to 25% involve injuries to the subclavian and axillary arteries.111 Forearm gunshot wounds have been found to account for up to 20% of gunshot wounds overall, of which pulse deficits of the radial and ulnar arteries have been reported to be as high as 86% and 83%, respectively.111,112 Furthermore, penetrating forearm injuries are the most common cause of upper-extremity compartment syndrome, with a rate of 10%.30,113

Lower-extremity ballistic injuries have the highest rate of fractures. The majority involve the femur (22%-49%); the tibia accounts for 11% to 14%.5 Injuries to the hip and bony pelvis carry significantly higher morbidity and mortality due to related injuries to the abdominal and pelvic organs.114 Thigh wounds carry significant potential for vascular injury with high risk of massive hemorrhage, especially when the injury involves the medial aspect of the thigh or when a severe femur fracture occurs.

Injuries to the leg, especially the tibia, can be especially devastating. Overall, the majority of compartment syndromes are found in tibial trauma from both blunt and penetrating injuries. Gonzalez showed that 60% of patients who developed compartment syndrome in penetrating lower extremity trauma had associated tibial fractures.115

Vascular Injuries Of Extremities

An extremity vascular injury can cause hemodynamic instability from significant exsanguination and can affect the viability of the injured limb. Neurovascular structures in the extremities travel closely together, from proximal to distal, while traversing compartments that are well-demarcated by fascia and muscle tissue. The fascial separations can play a critical role in injury patterns because they may act as a conduit for the transfer of kinetic energy from the projectile and can impart immediate injuries distal to the permanent cavity and late complications such as compartment syndrome. The timing of presentation for treatment is critical, as studies have shown that delays of greater than 6 to 8 hours have infection and complication rates that are significantly higher than in patients who present early after sustaining a firearm injury.112

A recent large review of the National Trauma Data Bank® from 2002-2005 looked at isolated lower-extremity trauma with an arterial component and found that penetrating trauma accounted for 66% of these injuries. The most commonly injured vessel is the superficial femoral artery, followed by the popliteal artery and the common femoral artery. The amputation rate from penetrating trauma is 5.1% and is most frequently associated with a popliteal artery injury.116

Gunshot wounds to the proximal aspect of the upper extremity warrant evaluation for brachial plexus injuries. One study noted that shotgun injuries to the shoulder carried a 50% chance of nerve transection.19 The more proximal the vessel injury, the higher the risk for significant injury. Additionally, patients with an underlying vascular disease are susceptible to more problematic injuries and merit a higher degree of clinical suspicion for associated vascular injury.

Traditionally, after physical examination, the gold standard for further assessment for a vascular injury has been conventional angiography.5,111 Historically, soft signs of vascular injury on physical examination were an indication to obtain angiography. However, other methods such as computed tomography angiography (CTA) have replaced conventional angiography in many circumstances. Conventional angiography’s advantage is that it has been consistently shown to have 99% sensitivity and 97% specificity.33,117 However, up to 95% of arteriograms are negative, they have a false-positive rate of 2%, they carry a complication rate of 1% to 3% (further arterial injury), and they often do not change management decisions.33 Prospective studies of CTA have shown sensitivities ranging from 99% to 100% and specificities of 87% to 100%.33,117,118 Duplex ultrasound offers some significant advantages to other study methods because it is readily available in many EDs, can be done at the bedside, is noninvasive, requires no radiation exposure or contrast material, and has a high degree of diagnostic accuracy in the experienced provider’s hands. Studies have shown sensitivities of 95% to 100%, with specificities of 97% to 98%.114,115

In the patient with equivocal signs of vascular injury, choosing the best diagnostic imaging test can be difficult. If no hard signs are found but there is still a concern for vascular injury, many institutions advocate admission and serial examinations along with some form of diagnostic testing such as duplex ultrasound or CTA.

Nerve Injuries In Extremity Trauma

Peripheral nerve injuries due to trauma are rare, accounting for only 2% to 3% of all traumatic injuries.121 Noble et al found that gunshot wounds accounted for 7.4% of peripheral nerve injuries overall (and as high as 84% in developing countries).122 Neurologic injuries are associated with a concomitant vascular injury in approximately 10% to 16% of cases.116,123

Nerve injuries are notoriously difficult to assess in the immediate setting, and there is considerable controversy as to the best management of these injuries. If the injury is neuropraxic (the nerve remains intact but is transiently nonfunctional) or axonometric (axon alone is severed), these patients will usually regain function. Nearly 70% of individuals with a documented peripheral nerve injury go on to make complete recovery.123 Focal neurologic findings have been suggested as risk factors for unrecognized vascular injury because of their proximity. Frequent reassessments of neurologic status are important because changes can also indicate development of compartment syndrome.

Management Of Bone And Joint Injuries

Bone and joint injuries are often grossly visible on examination and should be stabilized as soon as possible Realignment can provide hemostasis, reduce pain, and prevent further injury, such as compartment syndrome. Initial stabilization includes fracture reduction with the best possible anatomic realignment, soft tissue wound care, and appropriate splinting, with care to avoid constrictive dressings. Always reassess neurovascular status after these measures. If wounds are large, obviously contaminated, or involve the joints, IV antibiotics are indicated. Imaging of the injured area as well as the anatomic area above or below the wound should be performed.

A simple way to describe the fracture to an orthopedic consultant is to use the mnemonic NOLARD: Neurovascular status, Open versus closed, Location, Angulation/Alignment/Articular involvement, Rotation, and Displacement.119 Always include the mechanism of injury and estimate the level of contamination as well. Definitive treatment of joint and bone injures often requires operative treatment, and bone injuries may need to be repaired to facilitate a vascular repair.

A study by Brown et al found that firearms-related injuries accounted for 15% of all fractures requirining surgery.124 Fractures can occur from direct injury caused by the projectile, but bony fragments can also act as secondary missiles and lead to concomitant neurovascular injuries. Fractures caused by gunshot wounds are classified similar to other blunt trauma fractures. Incomplete fractures typically involve the epiphysis and metaphysis and have 3 patterns: drill hole (seen in cancellous bone injury), unicortical (usually in long bone metaphysis), and chip fractures. Complete fractures frequently involve the diaphyseal bone and have a butterfly pattern.34,113

High-velocity gunshot wounds to the bone are the most significant because severe comminution and devitalized bone fragments are often present. Low-velocity gunshot wound fractures, however, often behave similarly to closed blunt-trauma fractures.

Ballistic injuries to the joints can have devastating short- and long-term sequelae. An isolated gunshot wound to a joint is rare but requires immediate operative evaluation and management. These types of injuries are a risk for severe posttraumatic arthritis, and if left in place, retained fragments can lead to plumbism.125

While arterial injuries are the greatest threats to life and limb, overall, skeletal muscle and soft tissue are the predominant tissue types injured in gunshot wounds. High-velocity and shotgun injuries are typically the most severe. Low-velocity wounds are not typically associated with significant tissue damage and are generally lower-risk for infection.125,126

 
Get More Content Like This!
Enter your email below to get evidence-based updates delivered to your inbox once a month.

 

 

Purchase a
subscription
$349
Emergency Medicine Practice
 
Sign up for a free trial
Free 48-hour trial
Emergency Medicine Practice
 

Related Links:

trauma 2 ballistic

 
About EB Medicine:
Products:
Accredited By:
ACCME ACCME
AMA AMA
ACEP ACEP
AAFP AAFP
AOA AOA
AAP AAP
Endorsed By:
AEMAA AEMAA
HONcode HONcode
STM STM

 

Last Modified: 08/16/2018
© EB Medicine