|Ankle Brachial Pressure Index|
What is it:
A Simple method of quantifying the severity of arterial occlusion in the leg.
How is it measured:
A vascular cuff is placed around the lower calf muscle above the ankle joint and a 8MHz (5 MHz in obese patients) doppler probe is placed over the dorsalis pedis artery and then posterior tibial artery. (or peroneal artery if no audible sould is heard from the other two)
The cuff is then inflated for each artery, the value taken is the maximum cuff pressure where the pulse is only just audible. This is then related to the peak systolic blood pressure measured at the brachial artery.
ABPI = Brachial Systolic BP / Ankle Systolic BP
What does it mean:
Peripheral arterial disease (PAD) is usually present if the ABPI is less than 0.95. Many patients with reduced ABPI are symptom free however the following table gives some idea of the symptoms associated with various severities of peripheral arterial disease:
Clinical status ABPI
Symptom free 1 or more
Intermittent claudication 0.95 - 0.5
Rest pain 0.5 - 0.3
Gangrene and ulceration <0.2