72 year-old female presents to your emergency room for excruciating, “10/10” left leg pain. Patient states that pain awoke her from sleep two days ago, but she never went to the emergency department because she hates doctors. She states she’s having trouble moving her left leg now, and family members noticed it looks different than her right leg.
What do you think is going on?
This patient is most likely experiencing acute limb ischemia. The most common causes of acute limb ischemia are thrombotic occlusion. The second most likely cause is embolic occlusion. The difference between thrombotic and embolic occlusion can be difficult to distinguish. Some clues in the history and physical exam that favor embolic occlusion include acute onset and normal exam in the contralateral side. Embolic occlusion is usually an acute process, whereas thrombotic disease is usually a gradual process.
Let’s say our patient has an embolic occlusion….
What can you anticipate about her medical history?
This patient will likely have some pro-thrombotic process and is not properly anticoagulated. Most emboli originate in the heart. The most common cardiac cause of embolus formation is atrial fibrillation. Other sources include recent myocardial infarction causing abnormal cardiac wall motion, mechanical valves, cardiac myxomas, and vegetations (sometimes due to endocarditis leading to mycotic emboli). Noncardiac embolic sources are less common. They include aneurysms and atheroemboli from plaques that break off and travel within the circulation.
The infamous 6 Ps- Can you name them all?
Pain, pallor, paralysis, pulselessness, paresthesias, and polar/ poikilothermia (for cold)
What are some physical exam findings that will help you clinch the diagnosis?
Keep in mind that for patients with a more chronic disease course, physical exam findings may not be as dramatic and acute as in this case.
- Pain is usually the first symptom which can evolve into hypoesthesia/paresthesias.
- Skin changes appear first as pallor eventually evolving to blotching, mottling, and cyanosis (as in our patient). In severe cases, you may find skin necrosis.
- Pulse difference between two extremities is a sign of acute ischemia.
- Ankle-brachial index may also help determine the severity of disease.
Could a deep vein thrombosis present the same way?
Phlegmasia alba dolens and phlegmasia cerulea dolens describe a severe form of deep vein thrombosis that may present acutely and dramatically similar to an acute arterial emboli. Phelgmasia alba dolens and phlegmasia cerulea dolens are different spectrums of the same disease process.
In phlegmasia alba dolens, collateral veins are spared, the limb appears white (hence “alba”) but not cyanotic. Phlegmasia cerulea dolens also affects the collateral veins causing severe venous congestion. If left untreated, phlegmasia cerulean dolens can lead to gangrene and limb loss.
Phlegmasia alba dolens has been described in pregnant women in their third trimesters when the uterus was large enough to compress the common iliac vein. However, both phlegmasia alba dolens and phlegmasia ceulea dolens are most commonly associated with malignant process. Ultrasonography will help differentiate between venous thrombosis and arterial process.
What labs or imaging would you acquire in the ED?
- ECG to make sure patient is not in atrial fibrillation (which could also be assessed with a good cardiac exam) and to screen for signs of recent MI
- Coagulation panels
- Cardiac markers
- Creatine kinase and lactate levels will also be important. Limb ischemia can have systemic effects aside from the effects on the extremity.
- Doppler ultrasonography
How would you treat this patient in the ED?
- Anticoagulation: Give full dose 325mg aspirin and start with 80 units/kg bolus of heparin and initiate 18 units/kg heparin drip.
- Pain control: Remember to provide adequate analgesia for these patients.
How would you disposition this patient?
This patient needs emergent vascular consult and possible surgery to re-vascularize the limb. If the patient is not a candidate for revascularization, the patient should be admitted for anticoagulation.
Chopra, Anil, and David Carr.. “Chapter 64. Occlusive Arterial Disease.” Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. Eds. Judith E. Tintinalli, et al. New York, NY: McGraw-Hill, 2011, http://accessmedicine.mhmedical.com.newproxy.downstate.edu/content.aspx?bookid=348&Sectionid=40381529.
Remember, what we do in practice may not always be the right answer on the exam. Frustrating, I know, but don’t lose a leg over it.
Special thanks to Dr. Silverberg and Dr. deSouza