Management Before Treatment

Diagnostics

Clinical Presentation

Acute arm ischemia is usually apparent on the basis of the physical examination. The symptoms are often relatively discreet, especially early after onset. The explanation for this is the well developed collateral system circumventing the brachial artery around the elbow, which is the most common site for embolic obstruction. The “six Ps” – pain, pallor, paresthesia, paralysis, pulselessness, poikilothermia – are applicable also for acute arm ischemia, but coldness and color changes are more prominent than for the legs. Accordingly, the most common findings in the physical examination are a cold arm with diminished strength and disturbed hand and finger motor functions. Tingling and numbness are also frequent. The radial pulse is usually absent but is pounding in the upper arm proximal to the obstruction. Gangrene and rest pain appear only when the obstruction is distal to the elbow and affects both of the paired arteries in a finger or in the lower arm. Ischemic signs or symptoms suggesting acute digital artery occlusion in only one or two fingers, imply microembolization.

Only the few patients with uncertain diagnosis, and those with a history and physical findings that indicates thrombosis, need additional work-up. Examples include patients with a history of chronic arm ischemia (arm fatigue, muscle atrophy, and microembolization) and bruits over proximal arteries. Angiography should then be performed to reveal the site of the causing lesion. Duplex ultrasound is rarely needed to diagnose acute arm ischemia but may occasionally be helpful.

Even though symptoms and examination findings may be so subtle that conservative treatment is tempting, surgical removal of the obstruction is almost always preferable. It has been suggested that in patients with a lower-arm blood pressure >60 mmHg embolectomy can be omitted, but such a strategy has not to our knowledge been evaluated systematically. In a patient series of nearly symptomless acute arm ischemia, which was left to resolve spontaneously or with anticoagulation as the only treatment, late symptoms developed in up to 45% of the cases. Surgical treatment is also fairly straightforward. It can be performed using local anesthesia and is associated with few complications. Very often an embolus is a manifestation of severe cardiac disease, so the patient’s cardiopulmonary function should be assessed and optimized as soon as possible. Preoperative preparations include an electrocardiogram (ECG) and laboratory tests to guide anticoagulation treatment. Heparin treatment is started perioperatively and continued postoperatively in most patients.

Дата добавления: 2014-12-23