Why the Peripheral Vascular Exam Matters
Peripheral arterial disease (PAD) affects over 1 in 5 people over 60 in the UK. The peripheral vascular examination assesses the arterial and venous supply to the limbs — a skill you will use every week as a junior doctor reviewing leg ulcers, assessing post-operative limbs, and investigating claudication. In OSCEs it appears both as a pure examination station and as part of broader surgical stations.
The key distinction you must demonstrate to the examiner is the difference between arterial and venous disease — they look different, feel different, and have completely different management.
💡 Tip
Opening move: After washing hands and introducing yourself, expose both legs fully from groin to feet. Position the patient lying flat. Say: "I'd like to start by looking at both legs together before examining each in turn."
The Peripheral Vascular Examination: Systematic Approach
1. General Inspection (From the End of the Bed)
Look at the patient's general appearance:
- Complexion: Pale, mottled (arterial), or rubor (dependent redness from PAD)
- Body habitus: Obesity, signs of diabetes (acanthosis nigricans, insulin injection sites)
- Tar staining on fingers — smoking is the biggest risk factor for PAD
Then look at the legs:
- Skin changes: Shiny, hairless, thin skin (arterial); lipodermatosclerosis, haemosiderin staining, varicose eczema (venous)
- Ulcers: Note site, edge, base, depth, surrounding skin
- Colour: Pallor or cyanosis; rubor on dependency
- Swelling: Unilateral (DVT, lymphoedema, venous) vs bilateral (heart failure, hypoalbuminaemia)
- Amputations or surgical scars
💎 Clinical Pearl
Arterial vs Venous Ulcer — the key differences:
| Feature | Arterial Ulcer | Venous Ulcer |
|---|---|---|
| Site | Pressure points, toes, heel | Gaiter area (medial malleolus) |
| Edge | Punched out, well-defined | Sloping, irregular |
| Base | Pale, necrotic, painful | Granulating, sloughy |
| Surrounding skin | Shiny, hairless, cold | Haemosiderin, lipodermatosclerosis |
| Pain | Severe (worse at night, relieved hanging leg out) | Mild–moderate (relieved by elevation) |
| Pulses | Absent | Present |
2. Temperature
Using the back of your hand, compare temperature at equivalent levels of both legs moving from distal to proximal. A demarcation line (sudden transition from cold to warm) indicates the level of arterial occlusion.
3. Capillary Refill Time
Press on a nail bed for 5 seconds and release. Normal refill ≤2 seconds. Prolonged refill indicates poor perfusion.
4. Pulses
Palpate all peripheral pulses systematically and compare sides:
| Pulse | Location | Technique |
|---|---|---|
| Femoral | Midpoint of inguinal ligament (ASIS to pubic tubercle) | Two fingers, firm pressure |
| Popliteal | Popliteal fossa, knee slightly flexed | Thumbs anteriorly, fingers in fossa |
| Posterior tibial | Behind medial malleolus | Two fingers |
| Dorsalis pedis | Between 1st and 2nd metatarsals on dorsum | Two fingers |
⚠️ Red Flag
The popliteal pulse is the hardest to feel — flex the knee to ~30°, place both hands around the knee with fingers deep in the popliteal fossa. Roll gently. A bounding popliteal pulse in an older patient suggests a popliteal aneurysm — mention this to the examiner.
Grade pulses as: 0 (absent), 1+ (diminished), 2+ (normal), 3+ (bounding).
5. Buerger's Test
This tests for severe arterial insufficiency:
- 1Lift the leg to 45° and hold for 1–2 minutes. Look at the plantar surface of the foot.
- Normal: remains pink
- Abnormal: pallor (arterial insufficiency — blood drains away and cannot be replenished)
- 1Sit the patient up and hang the leg dependently over the side of the bed.
- Normal: foot pinks up immediately
- Abnormal: reactive hyperaemia (rubor) — the foot turns brick red/dusky as blood floods back into maximally vasodilated vessels
A positive Buerger's test (pallor on elevation, rubor on dependency) indicates severe PAD. Buerger's angle is the angle at which pallor appears — less than 20° indicates critical ischaemia.
🧠 Mnemonic
Buerger's = "Pale Up, Red Down"
Elevate → Pale (arterial blood can't reach the foot against gravity)
Depend → Red (reactive hyperaemia as ischaemic vessels maximally dilate)
6. Auscultation
Listen over the femoral arteries and aorta (midline umbilicus) for bruits — turbulent flow indicating stenosis or aneurysmal disease.
7. Ankle-Brachial Pressure Index (ABPI)
In an OSCE you may be asked to describe or calculate the ABPI rather than perform it:
- Use a handheld Doppler probe and a sphygmomanometer
- Measure systolic BP in the brachial artery (both arms — use the higher)
- Measure systolic BP at the posterior tibial and dorsalis pedis of each ankle (use the higher ankle pressure)
- ABPI = ankle systolic BP ÷ brachial systolic BP
| ABPI | Interpretation |
|---|---|
| > 1.3 | Falsely elevated (calcified, non-compressible vessels — common in diabetes) |
| 0.9–1.3 | Normal |
| 0.5–0.9 | Mild–moderate PAD (claudication) |
| < 0.5 | Severe PAD (rest pain likely) |
| < 0.3 | Critical limb ischaemia |
💡 Tip
ABPI > 1.3 with diabetes: Medial artery calcification makes vessels non-compressible, giving falsely high readings. In these patients, use toe pressures or duplex ultrasound instead. Never apply compression bandaging (for venous ulcers) without confirming an ABPI ≥0.8.
The 6 Ps of Acute Limb Ischaemia
If you encounter a cold, pale, pulseless leg, think acute limb ischaemia — this is a vascular emergency. Recognise it by the 6 Ps:
| P | Sign |
|---|---|
| Pain | Severe, sudden onset |
| Pallor | White/mottled limb |
| Paresthaesia | Pins and needles — nerve ischaemia |
| Paralysis | Cannot move the foot — late, sinister sign |
| Pulselessness | Absent distal pulses |
| Perishing cold | Cold to touch |
⚠️ Red Flag
Paraesthesia and paralysis indicate imminent irreversible muscle death. A limb with these features needs emergency vascular surgery within hours. This is not a "refer tomorrow" situation — call the vascular registrar immediately.
How to Present Your Findings
"On examination of the lower limbs, there was bilateral loss of body hair and shiny, thin skin to mid-calf level bilaterally. There was a 2 cm punched-out ulcer over the right first metatarsal head with a necrotic base and no surrounding cellulitis. The limbs were cold to the level of both knees. Capillary refill was 4 seconds bilaterally. Femoral pulses were present and equal; the right popliteal, posterior tibial, and dorsalis pedis were absent; the left popliteal was diminished and distal pulses absent. Buerger's test was positive on the right at 20°. These findings are consistent with severe bilateral peripheral arterial disease, with critical ischaemia on the right. I would like to complete the examination by measuring the ABPI and referring urgently to the vascular surgery team."
Common Examiner Follow-Up Questions
"What is the difference between intermittent claudication and rest pain?"
"Intermittent claudication is cramping pain in the calf — or buttock in aorto-iliac disease — that comes on with exercise and is reliably relieved by rest within a few minutes. It occurs because muscle oxygen demand during walking exceeds the supply from stenosed vessels. Rest pain is a more severe symptom — constant burning pain in the foot and toes that is worse at night and when supine (as gravity no longer assists perfusion), relieved by hanging the leg out of bed or dependency. Rest pain indicates critical ischaemia and is an indication for urgent vascular intervention."
"What investigations would you arrange for a patient with suspected PAD?"
"First-line: ABPI and arterial duplex ultrasound to characterise the level and severity of disease. Bloods including FBC, U&Es, HbA1c, fasting lipids, and coagulation. ECG and echocardiogram — PAD is a marker of generalised atherosclerosis so cardiac assessment is essential. If intervention is planned, CT angiography or MR angiography to map the anatomy prior to surgery or endovascular treatment."
"What is the medical management of peripheral arterial disease?"
"The cornerstone is aggressive cardiovascular risk factor modification: smoking cessation (the single most important intervention), antiplatelet therapy with aspirin or clopidogrel, high-dose statin therapy, tight blood pressure and glucose control in diabetics, and supervised exercise rehabilitation for claudication. ACE inhibitors are recommended to reduce cardiovascular events. Revascularisation — endovascular (angioplasty ± stenting) or surgical bypass — is reserved for critical ischaemia, rest pain, or severely limiting claudication not responding to conservative management."