The upper limb (usually the right upper limb) is exposed, the elbow should be at the same height as the heart, and the upper arm should be straight and slightly abduction. The cuff balloon part is aligned with the brachial artery,
Close to the skin, tied to the upper arm, the lower edge of the cuff should be 2-3 cm away from the elbow bend. The examiner knows the brachial artery pulse in front of the cubital fossa,
Then put the chest radiograph of the stethoscope on the brachial artery at the cubital fossa, and gently press the chest radiograph of the stethoscope to make it closely contact with the skin, without too much force or touching the cuff.
Never put it under the cuff. Then, inflate the cuff and auscultate while inflating until the brachial artery pulse disappears.
After the mercury column rises by 2.6-4.0 kPa (20-30 mmHg), it begins to deflate slowly, and the mercury column in both eyes slowly drops. According to Korotkoff staging method,
When you hear the first sound, the mercury column value is systolic blood pressure (L phase). As the mercury drops, the sound gradually increases (the second stage), and then there is a blowing sound.
(Stage 3), then the sound suddenly becomes smaller and deeper (Stage 4), and finally the sound disappears (Stage 5). Mercury column value is the diastolic pressure when the sound disappears.
Some diseases (coarctation of aorta, Takayasu arteritis, etc. ) you also need to measure blood pressure of lower limbs; The method of measuring blood pressure of lower limbs is the same as that of measuring blood pressure of upper limbs.
However, the patient should take a prone position, choose a wide cuff, tie it 3 ~ 4 cm above the popliteal fossa, and put the stethoscope on the artery at the popliteal fossa.
The method of measuring systolic blood pressure and diastolic blood pressure is the same as above. The upper limb blood pressure of normal people is slightly different, and the difference between the two sides is 0.66-1.3 kpa (5-10 mmhg).
When the blood pressure of upper and lower limbs is measured by cuff method, the blood pressure of lower limbs is about 2.6 ~ 5.3 kPa (20 ~ 40 mmHg) higher than that of upper limbs.
However, there was no significant difference in direct measurement of arterial puncture or intubation.