Clinical order sets (predefined templates) are one way to ensure patient safety and reduce risk. Creating order sets for the wound types seen in your department provides a common platform and support for clinical decisions related to a specific condition or medical procedure. Creating wound-specific laboratory values assist with the consistency of ordering and care. In this column, we discuss the clinical order sets for arterial ulcers.
Arterial insufficiency refers to impairment of arterial blood flow leading to tissue ischemia and, potentially, necrosis. Such impairment can occur acutely (eg, trauma, thrombosis) or chronically (eg, atherosclerosis). Both acute and chronic arterial insufficiency can lead to lower-extremity ulcers. Arterial insufficiency can occur at any level, from large arteries to arterioles and capillaries. Tissue ischemia that leads to leg ulcers tends to occur more as large vessel or mixed disease.
Obstruction of arterial flow can be classified as anatomic or functional. Anatomic causes of obstruction include thrombosis, emboli, atherosclerosis, and vasculitis. Functional impairment occurs with conditions such as Raynaud disease, where abnormal vasomotor function leads to reversible obstruction. Reversible ischemia tends to cause pain and infrequently results in ulceration. Aside from obstruction, other potential causes of impaired arterial flow include disruption (eg, trauma), fistulas, and aneurysms.
Ischemic ulcers tend to have a punched-out appearance; they are small and round and have smooth, well-demarcated borders. The wound base is typically pale and lacks granulation tissue. Wet or dry necrotic tissue may be present. Arterial ulcers tend to occur over the distal part of the leg, especially the lateral malleoli, dorsum of the feet, and the toes. They can be shallow or deep and are frequently painful. Typically, the patient complains of pain when the feet are elevated, especially at night, and states that the pain is reduced with leg dependence.
In addition to these common features, the physical examination may reveal a decrease in peripheral pulses; lack of hair over the distal leg; and cyanosis, pallor, and/or atrophy of the surrounding skin. Lifting the leg greater than 60 degrees can induce pallor in the ischemic limb. When dropped to a dependent position, the limb may become red (dependent rubor).
Revascularization is the key to the treatment of arterial ulcers secondary to peripheral arterial disease (PAD). Other measures may include topical therapy, conservative debridement, and pain control. Treatment is also directed at the pathogenic causes of arterial disease. For example, management of atherosclerosis includes exercise therapy, cholesterol reduction, smoking cessation, and control of blood pressure and blood glucose. Antiplatelet agents (aspirin, ticlopidine, clopidogrel) and xanthine derivatives (pentoxifylline) are commonly used to treat the symptoms associated with PAD. However, medical treatment alone has typically been of limited effectiveness for treatment of arterial ulcers.
To accurately manage the patient with an arterial ulcer, the clinician should obtain the following laboratory values:
* glucose
* lipids
* complete blood count
* eosinophils
* cryoglobulins
* antiphospholipid antibodies
* antinuclear antibody panel
* rheumatoid factor
The laboratory tests, in tandem with diagnostic tests, assist the clinician in making a more accurate and specific arterial diagnosis.
Additional diagnostic tests can be performed to assist in accurately diagnosing the patient's wound.
Angiography is considered the criterion standard for diagnosing arterial vascular disease. This procedure is indicated for patients who are candidates for revascularization procedures. The test has associated risks, including cholesterol plaque embolization, acute avascular occlusion, arterial damage, and contrast-induced nephropathy.
Magnetic resonance angiography is a noninvasive test to determine the presence and severity of arterial obstruction, such as PAD.
Transcutaneous oxygen pressure (TcPo2) measurement can assess for the presence of microvascular insufficiency. A measurement greater than 30 mm Hg indicates adequate perfusion; a value less than 20 mm Hg indicates disease. If the tissue surrounding an ulcer has a TcPo2 less than 20 mm Hg, the wound typically will not heal.
Remember, the clinical goal when evaluating a patient is confirmation of the diagnosis. Understanding the laboratory values and diagnostic tests that support the diagnosis is critical. No single assessment parameter confirms a diagnosis. Careful review of the patient's wound history, laboratory findings, diagnostic tests, and management modalities will support or place doubt on a tentative diagnosis that is based solely on case history data and clinical findings. Work with your medical director and staff to define the clinical order sets for your department.