lower limb ischemia


lower limb ischemia

Ischemia to one or both legs due either to chronic arterial obstruction caused by atherosclerosis or to acute obstruction caused by embolism.

Treatment

Treatment depends on the obstruction’s cause, location, and size. Mild chronic disease may be managed using supportive measures such as smoking cessation, hypertension control, and increased exercise. Medications that improve blood flow such as aspirin, pentoxifylline and cilostazol may improve symptoms in patients with intermittent claudication. Surgeries for arterial insufficiency in the limbs include arterectomy, balloon angioplasty, bypass grafting, and combinations of the above. Embolectomy, laser angioplasty, lumbar sympathectomy, patch grafting, stents, thromboendarterectomy, and thrombolytic therapy also may be required. Amputation becomes necessary with failure of reconstructive surgery or development of gangrene, persistent infection, or intractable pain.

Patient care

Patients with lower limb ischemia related to acute obstruction suffer severe to excruciating pain in the limb, leg pallor and coolness, and absence of palpable pulses below the arterial obstruction. Emergency intervention is required, using thrombolytic therapy, thromboendarterectomy, embolectomy, or other surgical intervention to restore circulation to the affected area. More gradual arterial occlusive disorders may be evidenced by intermittent claudication of the calves on exertion, reduced pulses in the ankles and feet, gradually increasing pallor, hair loss, coolness, pretrophic pain (heralding necrosis and ulceration), and, in the worst circumstances, gangrene of the extremity. Diagnosis is based largely on the patient’s history and physical examination, followed by supportive diagnostic studies such as Doppler ultrasonography and plethysmography, and arteriography.

Patient teaching should include explanations of diagnostic tests and procedures and prescribed exercise and medication regimens, proper foot care, and smoking cessation programs. For patients undergoing surgery, fluid and electrolyte balance is assessed and the patient prepared emotionally and physically. Postoperatively, vital signs and circulation are monitored, comparing the operative to the unoperated limb for color, temperature, and pulses, and the patient is closely observed for hemorrhage (hypotension and tachycardia), chest pain, or other vascular complications. Early ambulation is encouraged. When ischemic limbs or digits need amputation, the stump is checked for drainage and the amount and color recorded. The stump is elevated based on the surgeon’s or agency’s protocol, and pain is carefully assessed and relieved, with phantom limb pain explained to the patient. Discharge teaching should include plans for rehabilitation (in a rehabilitation center or as an outpatient), signs to report that could indicate graft occlusion or occlusion at another site, desired and adverse effects related to any medications prescribed, and the importance of scheduled follow-up visits.

See also: ischemia