Injury
Warning signs on physical exam
Indications for operating
Arterial laceration
Pulselessness and pallor distally; worsening pain
Inadequate collateral circulation; impending ischemia, uncontrolled bleeding
Venous laceration/degloving
Congestion; swelling; worsening pain; tense compartments; contamination
Insufficient venous outflow; compartment syndrome; impending infection
Crush injury
Congestion; worsening pain (especially with motion); tense compartments
Compartment syndrome; injury to adjacent structures
Injection injury
Pain; crepitus; pallor; presence of foreign body
Tissue necrosis; acute arterial insufficiency; foreign body reaction
Cannulation injury
Pallor; pain; enlarging mass; thrill/bruits
Arterial insufficiency; enlarging aneurism; AV fistula
Take a Thorough History
Once a time-sensitive, limb-compromising injury has been ruled out, a thorough history can point the physician to the cause of a vascular disorder before examination of the upper extremity. A history of trauma is the most common cause of an acquired vascular problem in childhood. The patient’s history is usually positive for a recent injury, such as contact with sharp object, a car accident, a crush injury, or a recent hospitalization during which time arterial or venous access was used. Less commonly, chronic repetitive minor insults can culminate in a vascular problem. If no obvious injury is elucidated in the history, ask about daily activities, sports, and playing musical instruments, any of which may cause repetitive small insults.
More chronic vascular disorders may come with a variety of symptoms, such as pain, swelling, deformity, asymmetry, numbness, or any combination of these. All five of these should be addressed in the history. Ask about the chronicity of each of these symptoms and whether these are constant, intermittent, waxing/waning, or associated with any particular activities or arm position. Seek out alleviating and aggravating factors. Also of importance are hand dominance and a history of prior injuries or surgery on the affected extremity.
A patient’s full medical history should be reviewed. Multiple comorbidities may contribute to or complicate a vascular disorder. These include coagulopathies, cold sensitivity, Raynaud’s phenomenon, rheumatoid arthritis, and drug or tobacco use. The presence of comorbidities will help guide treatment options. Finally, any suspicion of abuse should be reported immediately.
Perform a Detailed Physical Exam
The vascular exam begins with evaluating the hand for warmth, color, and capillary refill. Brachial, radial, and ulnar pulses should be palpable at their usual landmarks at the antecubital crease, radial wrist, and ulnar wrist, respectively. Because of backflow and collateral flow, the ulnar and radial arteries should be isolated on exam to ensure patency; this can be done by occluding the ulnar artery while the radial artery is palpated, and vice versa. Allen’s test helps determine the patency of the palmar arches and the ability of the hand to be perfused adequately on either the ulnar artery or the radial artery alone (Koman et al. 1999; Zhongyu et al. 2010).
Allen’s test consists of elevating the hand while the patient makes a fist for at least 30 s. Manual pressure is used to occlude both the ulnar and radial arteries. After 30 s, the hand is opened, appearing pale from lack of blood flow. Pressure over the ulnar artery is released, and return of color to the entire hand is anticipated within 5–7 s. If color return is sluggish or absent (particularly in the index or thumb), then the ulnar artery cannot sufficiently supply the entire hand, and the radial artery should not be placed at risk (e.g., with an arterial line or radial forearm flap). Likewise, the radial artery is tested by repeating the above test, except that one should release the radial artery while maintaining occlusion of the ulnar artery. Color return within 5 s is considered normal (Zhongyu et al. 2010).
When pulses are not palpable, one should evaluate the presence of a dopplerable signal with a handheld Doppler. This device can also detect flow in the palmar arches and the digital arteries, which are normally not palpable.
More chronic vascular problems may reveal more subtle physical exam findings. The fingertips should be examined closely for any signs of ulceration, indicating insufficient blood flow or collagen vascular disease. Likewise the nails should be examined for splinter hemorrhages, indicating systemic cardiovascular problems. The turgor, color, and health of the skin, as well as the presence of scars, should be noted.
Because the vascular structures travel in close proximity with nerves, it is difficult to injure one without the other. A full motor and sensory exam should be included in every vascular evaluation.
If there is any sign of vascular insufficiency (cold, pale digits; ulceration of tips; etc.), the presence and quality of the pulses proximal to the abnormality should be evaluated. Additionally, the compartments of the hand, forearm, and arm should be examined for tenseness; substantial swelling can secondarily occlude blood flow distally. Compartment syndrome should be suspected in cases of swollen extremities with unremitting pain that worsens during range of motion. Additional signs in children are anxiousness and agitation.
The vascularity of an extremity is dependent on the health of the entire cardiovascular system, which is in turn dependent on overall clinical health. Systemic problems may manifest as a presumed isolated limb problem. Vascular workup in the extremities should include auscultation of the heart and cardiac workup as necessary.
Many people have minor anatomic variations. Always use the asymptomatic extremity as a comparison during an extremity exam. Many physicians advocate examining the unaffected hand first to obtain a baseline “normal,” with which to compare the affected extremity.
Finally, the vasculature is under considerable neurological, thermal, and chemical regulation with varying levels of stress. One normal exam does not rule out a vascular disorder. If stressors are known to aggravate symptoms, patients should be examined in the presence and absence of that stressor. For example, if cold intolerance is a symptom, patients should undergo exam before, during, and after a monitored cold stress test.
Use Adjunct Tests as Necessary
Where the physical exam is limited, there are numerous adjunct tests that can be used to assist with the workup. One of the most common and powerful tools is the Doppler ultrasound, which noninvasively evaluates the vasculature using sound waves. This device not only evaluates the location and patency of a vessel, but can also determine the direction, speed, and quality of the blood flow. Anatomic branching patterns, variants, and aneurysms can also be seen. Color duplex imaging is a combination of ultrasound and color-coded Doppler examination and is used to distinguish soft tissue masses from vascular anomalies such as aneurysms or pseudoaneurysms (Koman et al. 1999; Harkess 2000). It is also routinely used to evaluate for blood clots.
Skin temperature is an estimate of global systemic perfusion. When there is a suspected difference in perfusion within the hand or between the right and left hands, a skin temperature probe can be used to measure temperatures focally. These measurements are only accurate reflections of blood flow at temperatures between 20 °C and 30 °C. Surface temperature measurements and/or thermistors are also useful in cold stress testing of the autonomic system and vasomotor response. In the cold stress test, temperature and Doppler flow measurements in digits are recorded before, during, and after exposure to 5–8 °C air. This diagnostic test can be valuable in cases of suspected Raynaud’s phenomenon or collagen vascular disease.
If perfusion problems are suspected, pulse oximetry can be used to measure oxygenation of one digit compared to another or between hands. Pulse oximetry is noninvasive. Once taped to the skin, the probe sends light of two different wavelengths through the skin and measures the difference in absorption of these wavelengths, in order to determine the amount of oxygenated hemoglobin in pulsing arterial blood.
More extensive information requires more invasive testing. Magnetic resonance angiography (MRA) outlines the arterial and venous anatomy in three dimensions, localizing focal defects, occlusions, and watershed zones. This does require administration of an intravenous contrast agent. Formal contrast angiography requires vessel cannulation but provides detailed information of vascular architecture, timed direction of blood flow, collateral blood flow, and venous outflow (Koman et al. 1999). It also provides on-table access for intervention, such as lysis of clot. Downsides of formal angiogram include risk of vasospasm and intimal damage from the cannulation, contrast reactions, and embolic phenomenon. Both techniques have undergone noteworthy advancement as computer technology improves.
Other less commonly used vascular tests include digital plethysmography, segmental arterial pressures, capillaroscopy, and bone scans. Each has its own benefits and limitations.
Diagnosis and Treatment, by Type
Direct arterial Laceration
The arterial tree runs superficially in the upper extremity at many points along its course, making it extremely vulnerable in cases of sharp trauma. Pulsatile bleeding should be considered an arterial injury until proven otherwise; focal, direct pressure to the bleeding area using gauze should be applied immediately before and throughout the workup. Tourniquets are often applied in the field and should be taken off as soon as possible, as they contribute to global tissue ischemia and neuropraxia in all tissue distal to the level of injury. Irreversible tissue damage occurs when the tourniquet is on for more than 2h. The ATLS protocol should be initiated upon arrival to the hospital.
In addition to the general questions noted above (hand dominance, history of injuries, etc.), patients should be questioned on the mechanism of injury, sterility of injury setting, tetanus status, and risk of foreign object/glass in wound.
The physical exam should be approached with caution, in the event that a sharp foreign object remains embedded in the wound. Many advocate an x-ray before any wound inspection. First, the hand distal to the injury should be inspected for color, temperature, and capillary refill. If the distal extremity is pale and cold with weak or absent pulses, then the transection has likely occurred at a critical point in the anatomy with inadequate collateral flow. These injuries should be taken to the operating room immediately for repair. In some cases, collateral flow may continue to perfuse the distal extremity. Repair in this less critical situation is still advocated, especially in children. Because nerves travel with arteries in the upper extremity and because muscle and tendon tend to cover these structures, a complete sensory and motor exam distal to the injury should be performed. When inspecting the wound, small pieces of debris or glass may be removed with saline irrigation. Imbedded foreign bodies should not be dislodged until the patient is in a controlled operating room environment.
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