Peripheral Arterial Disease

Procedure

Palpate the femoral, popliteal, posterior tibial and dorsalis pedis pulses on both sides and grade each as normal, reduced or absent. Listen over each femoral artery in the groin with a stethoscope.

Positive Finding

Reduced or absent pulses, or a whooshing sound (bruit) over the femoral artery.

Sensitivity / Specificity

Reference: Boyko EJ, Ahroni JH, Davignon D, Stensel V, Prigeon RL, Smith DG. Diagnostic utility of the history and physical examination for peripheral vascular disease among patients with diabetes mellitus. J Clin Epidemiol. 1997;50(6):659-68. Khan NA, Rahim SA, Anand SS, Simel DL, Panju A. Does the clinical examination predict lower extremity peripheral arterial disease?. JAMA. 2006;295(5):536-46.

Interpretation

Abnormal foot pulses or a femoral bruit make arterial disease more likely, and the first level at which a pulse is reduced suggests where the narrowing is. The dorsalis pedis pulse is absent in a small number of healthy people, so judge it together with the posterior tibial pulse and the other leg. Confirm with an ABI. From 631 people with diabetes attending a general medical clinic (Boyko 1997), with severe arterial disease (ABI 0.5 or below, 90 legs) as the reference. Accuracy for milder disease, or in people without diabetes, is likely to be lower. The figures are for diminished or absent foot pulses. For the bruit, a 2006 review (Khan et al.) found a femoral bruit raised the likelihood of arterial disease in people without symptoms (likelihood ratio 4.8). In people with leg symptoms, at least one bruit gave 5.6, no bruit at all lowered it (0.39), and normal pulses lowered it (0.38).

Procedure

Patient lying on their back. Raise the legs to about 45° for 1 minute to drain the veins, then ask the patient to sit up and hang the legs over the side of the bed. Time how long the veins on the top of the foot take to refill.

Positive Finding

Foot veins taking more than 20 seconds to refill.

Sensitivity / Specificity

Reference: Boyko EJ, Ahroni JH, Davignon D, Stensel V, Prigeon RL, Smith DG. Diagnostic utility of the history and physical examination for peripheral vascular disease among patients with diabetes mellitus. J Clin Epidemiol. 1997;50(6):659-68.

Interpretation

Slow refilling means reduced arterial inflow and makes significant arterial disease more likely. The test does not work in a leg with varicose veins, because the veins refill backwards from above. Confirm with an ABI. From 631 people with diabetes attending a general medical clinic (Boyko 1997), with severe arterial disease (ABI 0.5 or below, 90 legs) as the reference. Accuracy for milder disease, or in people without diabetes, is likely to be lower. A positive result (foot veins taking more than 20 seconds to refill after the legs are lowered) makes severe arterial disease more likely, but most people with severe disease test negative, so a normal result does not rule it out.

Procedure

Patient rests lying down for 5–10 minutes. Using a blood-pressure cuff and hand-held Doppler, measure the systolic pressure in both arms and at both ankles (posterior tibial and dorsalis pedis arteries). For each leg, divide the higher ankle pressure by the higher arm pressure.

Positive Finding

An ABI of 0.90 or below. A very high reading means the arteries are too stiff to compress, and the result cannot be trusted.

Sensitivity / Specificity

Interpretation

An ABI of 0.90 or below supports peripheral arterial disease; the lower the value, the more severe the disease. In older people and people with diabetes or kidney disease, stiff arteries can give a falsely normal or high reading, so toe pressures or a duplex scan may be needed. Usually done by a GP, practice nurse or vascular laboratory. From a 2010 review of 8 studies with 2,043 patients or legs (Xu et al.; abstract read), for an ABI of 0.90 or below against 50% or more narrowing on imaging. Sensitivity varied widely and was lowest in older people and in people with diabetes, whose stiff arteries can give falsely normal readings, so a normal ABI does not rule arterial disease out in these groups. The review reported specificity of 83–99%, but who made up the comparison groups could not be checked from the abstract, so specificity is not shown. The 95% / 100% previously stored was not supported.

Procedure

Ask the patient to walk at a steady pace on a flat surface (or on a treadmill in a vascular laboratory). Record the distance at which leg pain starts and the distance at which they have to stop.

Positive Finding

Cramping or aching in the calf, thigh or buttock that comes on with walking, at a similar distance each time, and eases within a few minutes of standing still.

Interpretation

Describes the pattern and severity of intermittent claudication and gives a baseline to track change. Vascular claudication eases on standing still; neurogenic claudication from lumbar spinal stenosis usually needs sitting or bending forward, and is often eased by leaning on a shopping trolley. Check foot pulses and ABI to confirm an arterial cause. This measures how far the patient can walk before leg pain starts. It is used to grade severity and track change over time, not to diagnose arterial disease, so no accuracy figure applies. The figures previously stored here could not be matched to a study.

Procedure

Vascular laboratory test. Cuffs are placed at the upper thigh, lower thigh, below the knee and at the ankle, and the systolic pressure at each level is measured with Doppler and compared between levels and with the other leg.

Positive Finding

A clear drop in pressure between two neighbouring levels.

Interpretation

Shows roughly where along the leg the narrowing is (pelvic, thigh or calf arteries), which helps plan imaging. Stiff, calcified arteries can make the readings unreliable. Not done in osteopathic practice.

Procedure

Ultrasound scan of the leg arteries in a vascular laboratory. It shows the artery wall and measures the speed of blood flow with Doppler.

Positive Finding

A visible narrowing or blockage, with a sharp rise in flow speed across the narrowed segment.

Interpretation

Usually the first imaging test after an abnormal ABI. It shows where the narrowing is and how severe it is, and helps plan treatment. Results depend on the skill of the person scanning. Not done in osteopathic practice.