Recent from talks
Ankle–brachial pressure index
Knowledge base stats:
Talk channels stats:
Members stats:
Ankle–brachial pressure index
The ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachium). Compared to the arm, lower blood pressure in the leg suggests blocked arteries due to peripheral artery disease (PAD). The ABPI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm.
The patient must be placed supine, without the head or any extremities dangling over the edge of the table. Measuring ankle blood pressures while seated can overestimate the ABI by approximately 0.3.
A Doppler ultrasound blood flow detector, commonly called Doppler wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually used. The blood pressure cuff is inflated proximal to the artery in question. Measured by the Doppler wand, the inflation continues until the pulse in the artery ceases. The blood pressure cuff is then slowly deflated. When the artery's pulse is re-detected through the Doppler probe the pressure in the cuff at that moment indicates the systolic pressure of that artery.[citation needed]
The use of ordinary, readily available, oscillometric blood pressure meters to measure ankle blood pressure has been evaluated, using a cuff sized for the arm. The oscillometric ABI (OABI) was found to be feasible, shows reasonable correlation with the 'gold standard' Doppler ABI (DABI), and to detect DABI lower than 0.9 with moderate sensitivity and good specificity. Authors of a study concluded that "a patient with OABI lower than 0.9 is likely to have significant PAD and should be aggressively treated. The OABI is less useful in patients with absent peripheral pulses on physical examination", and commented that "Few physicians measure ABI because it is technically challenging and time consuming. Oscillometric blood pressure monitors are readily available and easy to use."
The higher systolic reading of the left and right arm brachial artery is generally used in the assessment. The pressures in each foot's posterior tibial artery and dorsalis pedis artery are measured with the higher of the two values used as the ABI for that leg.
The ABPI test is a popular tool for the non-invasive assessment of Peripheral vascular disease (PVD). Studies have shown the sensitivity of ABPI is 90% with a corresponding 98% specificity for detecting hemodynamically significant (stenosis of more than 50%) in major leg arteries, defined by angiogram.
However, ABPI has known issues:
When performed in an accredited diagnostic laboratory, the ABI is a fast, accurate, and painless exam, however these issues have rendered ABI unpopular in primary care offices and symptomatic patients are often referred to specialty clinics due to the perceived difficulties. Technology is emerging that allows for the oscillometric calculation of ABI, in which simultaneous readings of blood pressure at the levels of the ankle and upper arm are taken using specially calibrated oscillometric machines.[citation needed]
Hub AI
Ankle–brachial pressure index AI simulator
(@Ankle–brachial pressure index_simulator)
Ankle–brachial pressure index
The ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachium). Compared to the arm, lower blood pressure in the leg suggests blocked arteries due to peripheral artery disease (PAD). The ABPI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm.
The patient must be placed supine, without the head or any extremities dangling over the edge of the table. Measuring ankle blood pressures while seated can overestimate the ABI by approximately 0.3.
A Doppler ultrasound blood flow detector, commonly called Doppler wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually used. The blood pressure cuff is inflated proximal to the artery in question. Measured by the Doppler wand, the inflation continues until the pulse in the artery ceases. The blood pressure cuff is then slowly deflated. When the artery's pulse is re-detected through the Doppler probe the pressure in the cuff at that moment indicates the systolic pressure of that artery.[citation needed]
The use of ordinary, readily available, oscillometric blood pressure meters to measure ankle blood pressure has been evaluated, using a cuff sized for the arm. The oscillometric ABI (OABI) was found to be feasible, shows reasonable correlation with the 'gold standard' Doppler ABI (DABI), and to detect DABI lower than 0.9 with moderate sensitivity and good specificity. Authors of a study concluded that "a patient with OABI lower than 0.9 is likely to have significant PAD and should be aggressively treated. The OABI is less useful in patients with absent peripheral pulses on physical examination", and commented that "Few physicians measure ABI because it is technically challenging and time consuming. Oscillometric blood pressure monitors are readily available and easy to use."
The higher systolic reading of the left and right arm brachial artery is generally used in the assessment. The pressures in each foot's posterior tibial artery and dorsalis pedis artery are measured with the higher of the two values used as the ABI for that leg.
The ABPI test is a popular tool for the non-invasive assessment of Peripheral vascular disease (PVD). Studies have shown the sensitivity of ABPI is 90% with a corresponding 98% specificity for detecting hemodynamically significant (stenosis of more than 50%) in major leg arteries, defined by angiogram.
However, ABPI has known issues:
When performed in an accredited diagnostic laboratory, the ABI is a fast, accurate, and painless exam, however these issues have rendered ABI unpopular in primary care offices and symptomatic patients are often referred to specialty clinics due to the perceived difficulties. Technology is emerging that allows for the oscillometric calculation of ABI, in which simultaneous readings of blood pressure at the levels of the ankle and upper arm are taken using specially calibrated oscillometric machines.[citation needed]
Recent media