Limb claudication MCQs

Whenever examining the lower limb ALWAYS check pedal pulses. The patient has chronic limb ischaemia, so there is likely to be atherosclerosis of the arteries of the right lower limb so it may be harder to palpate the pedal pulses. You should assess the capillary refill time as well; however, you will need to lie the patient down and raise his foot above the level of the heart, so you are truly measuring CRT and not venous reperfusion.

Other signs of limb ischaemia are:

• femoral bruits
• shiny, hairless skin
• cold peripheries and skin
• ulceration of feet

You may find AF in a patient with ischaemic limb pain, but this would more likely be acute than chronic. A distal inflamed right leg might indicate DVT and the dilated saphenous vein may indicate venous insufficiency, rather than an arterial disorder.

This is Buerger's test and the result showed a positive indication for peripheral artery disease. A normal limb would not go such a dark colour.

Allen's test is used to check for collateral circulation in the hands before doing an ABG. The Bainbridge reflex is a physiological rise in heart rate in a response to increased atrial pressure. Thomas' test examines hip flexion and Thompson's test is also known as the calf squeeze test and checks to see if the achilles tendon has ruptured.

The ankle-brachial pressure index is the first line investigation of choice. For each ankle, you take the highest systolic pedal pulse pressure and divide it by the highest systolic brachial pulse pressure. A score of 1-1.4 is 'normal', but still be suspicious of such a score if the patient is a diabetic. Note that, as of August 2024, the NICE guidelines are contradictory. Guidelines for peripheral arterial disease state that 1-1.4 is normal, but the guidelines for venous ulcers say that a level of 0.8-1.3 "... suggests no evidence of significant arterial disease." However, the latter is used to guide prescribing compression stockings for venous ulcers, not for the diagnosis of PAD.

The CT angiogram may be used to identify the location of any stenosis but is usually avoided for two reasons: patients are likely to have reduced kidney function due to renal artery stenosis so there is an increased risk of kidney damage from the contrast, and there is also a risk of dislodging emboli that then migrate to the feet causing 'trash foot'.

Tne ECG may be indicated if you were worried about heart failure, ischaemic damage to the heart or AF. Note that AF would more likely be associated with acute limb ischaemia. A lipid profile may be used in assessing his cardiovascular risk or monitoring and dietary interventions but has no indication here and we already know he is obese. Fasting blood glucose is of no relevance as we already know he is diabetic based on his HbA1c.

The Fontaine classification categorises ischaemic limb pain. Our patient would be level 2 - intermittent claudication. Pain at rest/nighttime (3) and necrosis/gangrene (4) are both signs of critical limb ischaemia and would need to be seen urgently by the vascular team.

The Rutherford classification is used to assess tissue viability.

The management of limb ischaemia includes:

• Modifying risk factors e.g. diabetes, hypertension, obesity...
• three month supervised exercise programme
• analgesia
• aspirin or clopidogrel

They might also be considered by angioplasty, stenting or a bypass graft.

Limb iscahemia affects the arteries so he is likely to develop an arterial ulcer caused by arterial insufficiency. Therefore the base of the ulcer may be dry and be slow to heal, or even necrotic. The other options described:

• A - pyoderma gangrenosum
• B - venous ulcer
• D - neuropathic ulcer e.g. secondary to diabetes
• E - grade 1 pressure ulcer
.

His diabetes puts him at an increased risk of a diabetic foot ulcer (D) but the question was specifically asking about the ulcer that could be causes by his vascular condition.

Check out some of our other questions about ulcers.

Remember the Rutherford classification is used to stratify how viable the limb is.

In a critical setting, heparin is initially given to all patients, even if they are expecting to receive surgery e.g. to insert a stent. Thrombolysis with tPA may be an option for definitive treatment but not initial treatment. Tranexamic acid would not be indicated here. Clopidogrel and aspirin may have a role to play in the future management of the patient, but not initially.

The patient will also need oxygen, analgesia and IV fluids. Analgesia will probably be paracetamol and opiates. Don't forget to prescribe laxatives and anti-emetics alongside the opiate.

Source: Royal College of Emergency Medicine.

The anterior tibial artery passes into the dorsum of the foot where it becomes the dorsalis pedis. This travels down to the first webspace and gives off deep branches into the sole of the foot.