[<< wikibooks] Emergency Medicine/Arterial
== Acute Arterial Occlusion ==
It happens when a embolus, most often from cardiac source, impacts in the arterial tree or when there is a local thrombosis, usually at the site of a atherosclerotic plaque or in patients with coagulation disturbance.

== Signs and Symptoms ==
The main symptom is pain on the affected limb, it usually has a sudden onset, but may become worse with time. In patients with previously stenosis the first symptom may be only a worse or new onset of claudication.
The affected limb is also cold, pulseless e pallor. Peripheral nerves injury is usually an early manifestation, starting with numbness evolving to completely motor and sensitive deficit.
Patients who are seen very soon may complain of pain localized where the occlusion occurred, it may helps in the therapeutic approach.

== Diagnosis ==
The diagnosis is usually made in clinical basis only. Image exams help to localize the site of obstruction, the extent of thrombosis and the source of embolus.
The main differential diagnosis are severe deep venous thrombosis (Phlegmasia) and compartimental syndrome.

== Classification ==
Acute arterial occlusion is classified in clinical basis only.
Class I: Minor symptoms, limb is warm and no neurologic damage has occurred.
Class II: Classic symptoms of acute limb ischemia, some neurologic damage, the limb must be viable.
Class III: Complete neurologic damage, extensive skin necrosis. The limb is not viable.

== Treatment ==
Except in cases where aortic dissection is a possibility, the initial treatment is anticoagulation. It helps to prevent clot propagation and lets internal fibrinolitic system acts.
Class I: No urgent treatment is necessary, the patient may be treated as a cladicant.
Class II: Urgent revascularization is necessary.
Class III: Amputation is the only treatment to be considered.