The ankle-brachial index (ABI) calculator
The ankle-brachial index (ABI) is a simple, reliable means for diagnosing PAD in 5 minutes . Blood pressure measurements are taken at the arms and ankles using a pencil
shaped ultrasound device called a Doppler. A Doppler instrument produces sound waves (not x-rays) and is considered noninvasive because it does not require the use of needles or catheters. The ABI test is simple enough to be performed in any doctor's office or vascular laboratory. Not only is the ABI one of the most reliable tests for PAD, it is also the least expensive.
With the patient in a supine position, the physician takes blood pressure readings from both arms; he then takes blood pressure readings from both ankles with a sphygmomanometer and Doppler device. After determining the posterior tibial artery systolic pressures, the ABI value is calculated by dividing the higher systolic pressure in each leg by the higher systolic brachial pressure.
Ankle-Brachial Index (ABI) Worksheet
ABI scores should be interpreted as follows:
- Greater than 0.90 = normal
- 0.71 – 0.90 = mild obstruction
- 0.41 – 0.70 = moderate obstruction
- Less than 0.40 = severe obstruction
The posterior tibial pressure is measured to provide a complete assessment of the extent of PAD in each limb. Some patients may have a congenitally absent dorsal pedis pulse, whereas others (especially the elderly or those with diabetes) have arterial calcification that may prevent occlusion of flow by the pressure cuff, causing an abnormally high reading. An ABI value greater than 1.30 is considered abnormal; these patients should be referred to a vascular laboratory for further testing.
Is this exam reliable?
Although the ABI is reliable, this test may not be accurate in all patients. Some patients with diabetes, kidney disease, or some elderly patients, may have rigid blood vessels. These may be difficult to compress with the blood pressure cuff and, in these patients, the ABI reading may not be accurate.
An other exams will work?
For patients with rigid ankle blood vessels toe pressure measurements can be taken since toe arteries are rarely rigid. This examination is called a toe brachial index (TBI)
What causes periphery artery disease?
The commonest cause in peripheral artery disease is vasculitis, this happens in older people, young women, diabetics and makes the blood vessels rigid. The disease is due to inflammation and changing to a anti-inflammatory diet helps in overall issue.
User-friendly resources that familiarize professionals with the ABI calculator are available to encourage the widespread and routine use of this test in the primary care setting.
Can I test at home ?
Not everyone has to undergo this test as many people can actually feel their pulses in their feet.
You can place a finger of the pulse points and feel the pulses. It only takes a minute and you know that blood is flowing.
If peripheral circulation is poor you will see hair growing weakly in that area , the skin color turns blue. The skin when pressed color does not return.
Are there alternatives to peripheral artery disease treatment?
Many alternative treatments are available, among them chelating, homeopathic, herbal have completely reversed peripheral artery disease. In inflammatory conditions like vasculits anti-inflammatory treatments are helping reverse the disease without need of surgery.