Образование Blue Toe Syndrome просмотров - 99
Acute Ischemia After Previous Vascular Reconstruction
A substantial number of patients have chronic leg ischemia and have undergone vascular reconstructions, so there is a high likelihood that emergency department physicians will have to take care of problems with postoperative acute leg ischemia in the operated leg. The clinical presentation of graft failure or occlusion is variable. An abrupt change in leg function and skin temperature accompanied by the onset of pain can occur any time after surgery, but especially within the first 6 months. Several years after the reconstruction it is slightly more common for progressive deterioration to occur and an eventual graft occlusion to pass unnoticed.
As discussed previously in this chapter the management principles are roughly the same as for primary acute leg ischemia. It is the status of the leg and the severity of ischemia that lead workup and management. Most patients will undergo angiography to establish diagnosis and to provide information about possibilities to restore blood flow. Thrombolysis is often the best treatment option because it exposes the underlying lesions that may have caused the occlusion. As for patients with acute ischemia, those with an immediately threatened leg after a reconstruction should be taken to the operating room and treated as fast as possible.
A toe that suddenly becomes cool, painful, and cyanotic, while pulses can be palpated in the foot, characterizes the classic presentation of blue toe syndrome. This has occasionally led to the assumption that the discoloration of the toe is not of vascular origin, and patients have been sent home without proper vascular assessment. Although coagulation disorders or vasculitis may contribute, such an assumption is dangerous. Atheroembolism is the main cause for blue toe syndrome and atheromatous plaques in the iliac or femoral arteries or thrombi in abdominal or popliteal aneurysms are the main sources. Blue toe syndrome can also present without palpable foot pulses. The presentation may then be less dramatic.
It is common that the patient does not notice the initial insult and wait to seek medical care until after several weeks. Ischemic ulceration at the tip of the toe may then be found in the examination. During the foot examination more signs of microembolization are usually found, including blue spots or patchy discoloration of the sole and heel. When both feet are affected it suggests an embolic source above the aortic bifurcation. The clinical examination should include assessing the aorta and all peripheral arteries, including pulses and auscultation for bruits. When pulses in the foot are not palpable, ankle blood pressure needs to be measured. In the search for aneurysms and stenoses patients need to be investigated with duplex ultrasound to verify examination findings. To prevent future embolization episodes lesions or aneurysms found should be treated as soon as possible.
Occasionally the pain is transient and the blue color will disappear within a few weeks. More common, however, is an extremely intense pain in the toe that is continuous and difficult to treat. Unfortunately, the pain often lasts several months until the toe is either amputated or healed.
The pain is best treated with oral opiates, and quite high doses are often required to ease the pain. A tricyclic antidepressant drug may be added to the regimen if analgesics are not enough.
While waiting for diagnostic studies and final treatment of the lesions, the patient is put on aspirin therapy. There is no scientific evidence for using other medications such as coumadin, steroids, or dipyramidole. Still, if suspicion for a popliteal aneurysm is high we recommend anticoagulation with low molecular weight heparin until the aneurysm is corrected.
Acute Ischemia After Previous Vascular Reconstruction A substantial number of patients have chronic leg ischemia and have undergone vascular reconstructions, so there is a high likelihood that emergency department physicians will have to take care of problems with postoperative acute leg ischemia in the operated leg. The clinical presentation of graft failure or occlusion is variable. An abrupt change in leg function and skin temperature accompanied by the onset of pain can occur any... [читать подробенее]