healing perspectivesA C L I N I CA L PAT H WAY TO S U C C E SSVOLUME 3 NO. 2 SPRING 2006 A PUBLICATION OF NATIONAL HEALING CORPORATION

wound

CRITICAL LIMB ISCHEMIA

Uncover the underlying causes Critical limb ischemia:Peripheral arterial disease results in the manifestation of many serious conditions, including critical limb ischemia (CLI). CLI is the end-stage of lower extremity PAD in which severe obstruction of blood flow results in ischemic rest pain, ulcers and a significant risk for limb loss. National Healing Corporations evidence-based Clinical Pathway ensures that the appropriate processes and procedures are put into place to identify nonhealing wounds caused by CLI. Appropriate diagnosis and care is crucial, especially given the variety of complications that can occur with chronic wounds. This edition of Wound Healing Perspectives is dedicated to covering the various etiologies and underlying causes associated with CLI, including diabetes, PAD, cigarette smoking, hypertension, hypercholesterolemia, family history, and lifestyle. We also review non-invasive treatments for CLI, diabetic foot ulcers, hyperbaric oxygen therapy for CLI patients, and prevention strategies for amputation. As always, we appreciate the opportunity to bring you interesting and informative insights. We hope you enjoy this installment of Wound Healing Perspectives.

Overview and treatment optionsCritical limb ischemia (CLI) is the term used for patients with chronic ischemic rest pain, ulcers, or gangrene attributed to inadequate blood flow or arterial occlusive disease. It is the progressive evolution and clinical manifestation of peripheral arterial disease (PAD). CLI differs from acute limb ischemia, which generally follows arterial thrombosis or peripheral thromboembolism. Patients with CLI often suffer from severe pain caused by ischemia, tissue loss, ischemic neuropathy, or a combination of these factors. The pain typically occurs at night when the patient is resting, and the episodes can last hours. Controlling the pain of CLI patients, therefore, is very important and is often achieved through reperfusion of the affected limb or administering large doses of analgesics (e.g. acetaminophen) on a regular basis, nonsteroidal antiinflammatory drugs, narcotics, or opiates (Diehm and Diehm, 2004). Physicians should assess the severity of a patients pain through use of pain scales or visual scales. (See Leriche-

CLI PATIENTS ARE AT A HIGH RISK OF MYOCARDIAL INFARCTION, STROKE, AND VASCULAR DEATH.

Fontaine classifications on page 2). A large percentage of patients with CLI have coexisting diseases, such as cardiovascular and renal disorders. Furthermore, since many CLI patients are (continued on page 2)

HIGHLIGHTS INSIDECLI non-invasive treatments...........................2-3 PAD: The forgotten risk factor ...............................4 Advise for CLI patients ..........4 Diagnosing PAD .....................5 Cost of diabetic foot ulcers ...5 Chronic kidney disease and diabetes...........................6 HBO and CLI patients ............7 Working with a Wound Healing Center ..........8

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Katy Rowland SVP Clinical Services, National Healing Corporation

6400 Congress Avenue Suite 2200 Boca Raton, FL 33487 561.994.1174

Critical limb ischemia (continued from page 1)smokers, lung diseases such as chronic bronchitis and bronchial carcinoma also are prevalent in this population (Diehm et al, 2004). CLI patients also are at high risk for myocardial infarction, stroke, and vascular death. Therefore, prompt referral to a specialized vascular center improves the success of their treatment and reduces the systemic risk in this population (Diehm et al, 2004). Leg revascularization procedures work well for patients with CLI (or those with disabling claudication) by providing sufficient blood flow to relieve rest pain and heal skin lesions. If not revascularized, patients with CLI can lose limbs or acquire other potentially fatal complications due to gangrene progression or sepsis (Novo, Coppola and Milio, 2004). For patients suffering from high-grade stenoses or short arterial occlusions, percutaneous transluminal angioplasty (PTA) is typically recommended as the first form of treatment. In those patients where amputation is not required and vascular reperfusion is not possible when using thrombolysis, angioplasty, or surgical reconstruction, medical treatment to improve microcirculatory blood flow should be considered (Diehm et al, 2004). Surgical procedures preferably endovascular techniquesare second on the list, offering patients a lower morbidity and mortality risk compared to open surgical revascularizations (Novo et al, 2004). In fact, advances in vascular and endovascular procedures in recent years provide a much better chance of limb salvage for many patients. As a result, patients who are at risk for CLI should be diagnosed early and treated promptly. Approximately 20-30% of CLI patients are not considered candidates for vascular or endovascular procedures, and therefore, amputation is often the only option. Primary amputation also is considered when there is an absence of distal vessels, especially in the case of advanced distal ischemia associated with a low Ankle-Brachial Index (ABI) value ( 200 m Pain-free walking distance < 200 m Rest pain, ankle arterial pressure > 50 mm Hg Rest pain, ankle arterial pressure < 50 mm Hg Trophic lesions, necrosis or gangrene PATHOPHYSIOLOGY Relative hypoxia Relative hypoxia Relative hypoxia Cutaneous hypoxia, tissue acidosis, ischemic neuritis Cutaneous hypoxia, tissue acidosis, ischemic neuritis Cutaneous hypoxia, tissue acidosis, necrosis PATHOPHYSIOLOGY CLASSIFICATIONS Silent arteriopathy Stabilized arteriopathy, non-invalidant claudication Instable arteriopathy, invalidant claudication Instable arteriopathy, invalidant claudication Instable arteriopathy, invalidant claudication

Stage III B

Stage IV

Evolutive arteriopathy

SOURCE: NOVO ET AL, 2004

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performed annually in the United States (Biamino, 2004). Contradictory studies on aggressive revascularization, however, do exist. Tunis et al (1991) reported that in the United States the increased use of interventional procedures (e.g. angioplasty, including stenting implant) between 19791989 did not result in fewer amputations. The rate of amputations, in fact, increased from 1 to 24 per 100,000 cases as did bypass surgery from

TO REDUCE THE RISK OF ADVERSE CARDIOVASCULAR EVENTS, OR EVEN DEATH, PATIENTS WITH CLI ARE URGED TO STOP SMOKING AS WELL AS SEEK PROPER TREATMENT FOR HYPERTENSION, DIABETES, AND HYPERLIPIDEMIA.

continued to smoke, versus 0 to 10% in those who refrained from smoking. In fact, even patients with severe end-stage PAD can benefit from smoking cessation (Diehm et al, 2004).

Risk factors for the development of CLI include age, smoking, Normal > 0.90 and diabetes Claudication 0.50-0.90 mellitus. Diabetic Rest Pain 0.21-0.49 patients are 10 times more likely Trophic lesions Tissue Loss necrosis or gangrene to need a major amputation than 32 to 65 per 100,000 non-diabetic PAD pacases. Conversely, Novo tients, so patients are et al (2004) reported that urged to aggressively a Swedish study revealed control their diabetes and that over an eight-year maintain fasting blood period there was a sugars below 120 mg/dL decrease from 42% to and post prandial sugars 27% in primary amputa< 180 mg/dL, according to tions associated with a Diehm et al. Chronic corresponding increase in management should aim revascularizations, at normalizing glycoheresulting in an overall moglobin levels to less decrease in amputation than 7% (Diehm et al, from 61% to 47%. 2004). Whats more, major amputation is Diehm et al (2004) also more frequent among reported that amputation PAD patients who smoke rates are highly correlatheavily. To reduce the risk ed with persistent cigaof adverse cardiovascular rette smoking. In two events, or even death, series, the amputation patients with CLI are rate was between 11% urged to stop smoking as and 23% in those whoANKLE-BRACHIAL INDEX VALUES AND CLINICAL CLASSIFICATION

well as seek proper treatment for hypertension, diabetes, and hyperlipidemia. Smoking cessation also improves the viability of graft patencies for both vein and prosthetic graft material (Diehm et al, 2004). Non-invasive tests to properly diagnose patients with PAD (as well as ascertain the severity of the limb ischemia) include measurement of the ankle/ brachial index or the ankle and toe Doppler pressures. The detection of transcutaneous PO2 and PCO2 and diagnostic imaging studies are also effective tests. It is important to note that diabetic patients often have falsely elevated ABI readings of over 1.3 (Seiman, 2000).

CLI noninvasive treatments(Continued)

arteries clogged with plaque so that patients can avoid or postpone amputation (Biamino, 2004). Pharmacotherapy (e.g. prostanoids): helps blood flow in CLI patients and could save 40% of lives and limbs. However, drugs will not replace surgery in CLI patients since surgery saves approximately 60% of limbs (Diehm et al, 2004). Topical therapies and hyperbaric oxygen treat ment: appropriate when revascularization has failed or is not technically possible. Reports on the use of hyperbaric oxygen in patients with early gangrene revealed that pain relief was obtained and amputations could be postponed.

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General advice for CLI patients

Peripheral arterial disease:

The forgotten risk factorPeripheral arterial disease (PAD) is atherosclerosis and artherothrombosis of the leg arteries. The primary symptom, known as intermittent claudication (IC), is pain in the calves on exertion caused by inadequate blood flow to the muscles due to narrowing or blockage of the arteries. Although seemingly innocuous, PAD is a serious clinical problem, potentially life-threatening and often goes undiagnosed since most patients are asymptomatic. Understanding the patients medical history combined with the use of non-invasive tests that measure the anklebrachial index (ABI) help in the diagnosis of PAD.