Ankle brachial pressure index
The ankle-brachial index (English scientific term: ankle -brachial index ( ABI) ), Doppler index, even tibio - brachial ratio ( TBQ ), cruro - brachial ratio ( CBQ ), or called wedge pressure measurement, blood pressure measurement and Doppler sonography detected. The determination of the ankle - brachial index is carried out for the estimation of total cardiovascular risk and in patients with peripheral arterial occlusive disease for the diagnosis and assessment of hemodynamic compensation and to follow the course.
Implementation
The patient must be placed in a recumbent position ( head can be supported with pillows ). Wait time before measurement 10 min. Then, in succession, a blood pressure cuff is applied far down on both lower legs and on both upper arms and measured the systolic pressure: Using the Doppler probe of the blood pressure cuff is on a vessel distally determined at reducing the pressure from when blood flows again. Alternatively, the measurement can be carried out by means of special devices. These devices simultaneously measure the blood pressure in all extremities, causing blood pressure fluctuations, the measurement result can not influence.
Evaluation
The ankle - brachial index is the ratio of the measured to the lower leg and upper arm systolic blood pressure ( RR systolic ankle / arm systolic RR ). A ratio of 0.9 to 1.2 is considered normal. The smaller the ratio is, the greater the extent of the blood circulation disorder. Values below 0.9 define the PAD. Values below 0.5 imply mostly been a clinical ischemia with very high necrosis and Ulkusgefahr. Values significantly above 1.3 indicate a particular type of vascular calcification through ( medial sclerosis ).
As per leg on two different vessels each, a value is measured (ABI value), it is currently in conformity with guidelines, to diagnosis, in forming the quotient to use the higher of the two ankle pressures. In the arms of the average of the measured pressures on both arms will be used. For systolic blood pressures after RR 200, this test is contraindicated and returns incorrect values .
Measurement Example
Measurement on the upper arm to 100 mm Hg, measured on the lower leg 50 or 60 mmHg. The ankle - brachial index is then 0.6, which corresponds to a PAD ( peripheral arterial disease ) in stage III -IV would correspond.