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KembaraXtra – Emergency & Acute Medicine – Peripheral Vascular Disease
Peripheral vascular disease (PVD), also known as peripheral artery disease (PAD), refers to obstruction of one or more peripheral arteries due to atherosclerosis, thrombosis, or embolism. Many patients also have coexisting coronary artery disease and cerebrovascular disease. Major risk factors include age, smoking, diabetes mellitus, hyperlipidemia, and hypertension. PVD is associated with significant morbidity and mortality related to systemic atherosclerosis. Complications include aneurysm formation, thrombosis, ulceration, limb loss, and progression to critical limb ischemia.
Chronic arterial insufficiency (CAI) results from progressive atherosclerotic narrowing that produces subacute ischemia and claudication. About 10% of patients progress to critical limb ischemia. Acute arterial insufficiency (AAI) is caused by arterial thrombosis (approximately 50%) or embolism and produces acute limb ischemia characterized by the “6 Ps.” Atheroembolism occurs when rupture or disruption of an atherosclerotic plaque in the aorta, iliac, or femoral arteries releases cholesterol emboli that obstruct small vessels. It is often precipitated by invasive arterial procedures such as cardiac catheterization.
Etiologies include atherosclerotic plaque obstruction, arterial thrombosis, cardiac emboli (commonly from atrial fibrillation, valvular disease, or cardiomyopathy), aneurysm, infection, tumor, vasculitis, foreign body, thrombosis superimposed on chronic disease, and atheroembolism.
Patients with CAI typically report claudication—aching calf pain in femoropopliteal disease or buttock and thigh pain in aortoiliac disease—brought on by exertion and relieved with rest or dependent positioning. Severe disease presents with rest pain, usually beginning in the foot, or rapidly progressive claudication and ulceration. Acute arterial insufficiency presents with sudden extremity pain that increases in severity, often beginning distally and progressing proximally. Pain may decrease once sensory loss occurs. Atheroembolism presents with cold, painful digits and may involve multiple organs including kidneys, mesentery, and skin, especially following recent vascular procedures.
On examination, sudden onset of pain and pallor in an extremity is limb- and life-threatening. In CAI, findings include diminished or absent peripheral pulses, delayed capillary refill, cool skin, prolonged venous filling time, bruits, pallor with elevation and dependent rubor, muscle and skin atrophy, thickened nails, hair loss, and toe or heel ulcerations. Acute arterial insufficiency presents with the 6 Ps: pain, pallor, pulselessness, poikilothermia, paresthesias, and paralysis. Identifying a potential embolic source such as atrial fibrillation is essential. Atheroembolism may show painful ischemic digits, “blue toe syndrome,” and livedo reticularis.
The ankle–brachial index (ABI) is an important bedside test in chronic disease. An ABI <0.9 is abnormal and <0.4-0.5 indicates severe disease. in patients with diabetes, calcified vessels may produce falsely elevated values (>1.3). Acute arterial insufficiency is primarily a clinical diagnosis based on the 6 Ps. Patients with acute-on-chronic disease may tolerate ischemia better due to collateral circulation. Atheroembolism is diagnosed clinically, with further evaluation to identify the embolic source.
Laboratory evaluation includes CBC, platelets, electrolytes, renal function, glucose, coagulation studies, and creatine phosphokinase to assess muscle ischemia. Additional studies may include inflammatory markers for vasculitis, blood cultures for suspected endocarditis, and hypercoagulable testing when indicated.
Doppler ultrasound is commonly used to identify the level of arterial occlusion and detect thrombosis or aneurysm. CT angiography is widely used as a first-line diagnostic tool and guides decisions for operative or endovascular intervention. Angiography allows simultaneous diagnosis and treatment with angioplasty, atherectomy, or thrombolysis. MRI is sensitive but less practical in emergency settings.
Differential diagnoses include acute thrombosis or embolism, arterial dissection, deep venous thrombosis, venous insufficiency, compartment syndrome, Buerger disease, spinal stenosis, neuropathy, bursitis, arthritis, and reflex sympathetic dystrophy.
Prehospital care includes maintaining hemodynamic stability, placing the limb at rest in a dependent position, providing oxygen when needed, and cardiac monitoring. In the emergency department, management includes IV fluids for hypotension, cardiac monitoring, supplemental oxygen, adequate analgesia, and avoidance of temperature extremes.
Management of chronic arterial insufficiency includes antiplatelet therapy with aspirin (75–325 mg daily) or clopidogrel (75 mg daily). Cilostazol, pentoxifylline, or dipyridamole may be used in selected patients. Risk-factor modification is essential and includes smoking cessation, lipid and blood pressure control, diabetes management, and structured exercise therapy. Revascularization options include balloon angioplasty, atherectomy, or bypass grafting depending on anatomy and severity.
Acute arterial insufficiency requires immediate IV heparin (80 U/kg bolus followed by infusion at 18 U/kg/hr), unless aortic dissection or aneurysm is suspected. Emergent consultation with vascular surgery or interventional radiology is mandatory. Revascularization must occur within 4–6 hours of symptom onset to prevent irreversible ischemia. Treatment options include thrombectomy, embolectomy, angioplasty, thrombolysis, or bypass grafting. Complications include compartment syndrome, irreversible limb ischemia requiring amputation, rhabdomyolysis, renal failure, and electrolyte disturbances.
Atheroembolism is managed conservatively when tissue involvement is limited and renal function preserved. Treatment is supportive with wound care and analgesia. Vascular surgery referral within 12–24 hours is recommended, and evaluation to prevent further embolic events is essential. Amputation may be required for irreversibly necrotic tissue.
All patients with acute arterial insufficiency require hospital admission for evaluation and revascularization. Patients with chronic disease should be admitted if they develop rapidly progressive claudication or ischemic rest pain. Atheroembolism warrants admission if there is significant tissue involvement, infection, pain, or renal compromise. Stable patients with mild chronic disease or limited atheroembolism may be discharged with close follow-up.
Early recognition of acute limb ischemia is critical, as time to reperfusion determines limb salvage and survival.
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