Amy M. Stubbs
EPIDEMIOLOGY
More than 50% of penetrating traumatic injuries involve the extremities. This accounts for up to 82% of vascular injuries to the extremities.
Penetrating injuries to the extremities result in amputation in <5% of cases.
Injuries to major nerves are the most likely to lead to long-term disability.
Gunshots and stab wounds account for the majority of penetrating extremity injuries.
PATHOPHYSIOLOGY
Injuries from stab wounds may be predicted based on the anatomy of the area.
Tissue damage from a missile or blast injury is variable and dependent upon multiple factors.
CLINICAL FEATURES
After the primary and secondary surveys are completed, including appropriate resuscitation, perform a thorough history, including the events surrounding the injury, type of weapon used, and any prior injuries to the affected limb.
A detailed examination should be performed on the affected extremity, quickly noting any “hard” signs of vascular injury that require immediate intervention. “Soft” signs of arterial injury should be noted as well (Table 170-1).
Wound characteristics, bony deformities, soft tissue defects, and location of pain should be evaluated and noted.
Examine range of motion, strength and sensation, adjacent joints, and the surrounding compartments; concerns for compartment syndrome, open joint, and arterial or nerve injury warrant emergent consultation with the appropriate specialist.
TABLE 170-1 Clinical Manifestations of Extremity I Vascular Trauma
DIAGNOSIS AND DIFFERENTIAL
Diagnosis of significant extremity injuries may require imaging and measurement of ankle-brachial indices (ABIs).
Plain radiographs of the affected limb and the joint above and below the injury are useful to diagnose bone and joint injuries, retained foreign bodies, and embolized bullet fragments.
Although traditional angiography is considered the gold standard for identifying vascular injuries, multide-tector CT (MDCT) angiography is rapid, noninvasive, sensitive, and specific for vascular injuries, as well as fractures and foreign bodies.
Duplex ultrasonography is rapid, safe, and accurate for the detection of vascular injury. It can also assist in identifying foreign bodies and may be the preferred imaging modality in some cases.
ABIs are performed by measuring the systolic blood pressure in all four extremities with the patient supine, using a manual blood pressure cuff and Doppler. An ABI is then calculated by dividing the ankle systolic blood pressure by the greater of the two systolic upper extremity systolic blood pressures.
An ABI ≥1.0 = normal, 0.5 to 0.9 = injury to a single arterial segment, <0.5 = severe arterial injury or injury to multiple segments of the artery.
ABIs have variable sensitivity and specificity for arterial injury, and may be affected by underlying conditions such as peripheral vascular disease and hypothermia.
ABIs are not reliable for detecting intimal flaps or psuedoaneurysms.
EMERGENCY DEPARTMENT CARE AND DISPOSITION
For patients with “hard” signs of arterial injury, immediate surgical intervention or expedient vascular imaging is required.
Vascular imaging in patients with “soft” signs of arterial injury is controversial. Most can be managed conservatively with admission for 24-hour observation and serial examinations, as incidence of significant injury in this group is low. Rapidly initiate intervention and/or imaging if signs of vascular compromise develop.
Control bleeding with direct pressure. Do not clamp or ligate blood vessels in the ED.
Open fractures or joints should be evaluated by an orthopedic surgeon. Fractures due to penetrating injury require surgical debridement and parenteral antibiotics (cephalosporin ± aminoglycoside).
General principles of wound management including irrigation, debridement, and tetanus prophylaxis apply. Copious irrigation with saline or tap water at high pressure is a key component.
Primary closure of low-risk wounds may be considered. Delayed primary closure (72-96 hours post injury) may be appropriate in some cases.
Prophylactic antibiotics are generally not indicated. Consider immunocompromised patients to have high-risk wounds.
If considering wound exploration for foreign body removal, the clinician should take into account size, location, material, and risk/benefit ratio to the patient.
Patients with no signs of significant injury, minimal tissue damage, and an unremarkable examination after an observation period may be safely discharged.
For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 263, “Penetrating Trauma to the Extremities,” by Roberta Capp and Richard D. Zane.