Check to make sure the aneroid manometer is calibrated correctly
When you look at the dial, make sure it is at the zero baseline before starting. If it isn’t, you need to calibrate it using a mercury manometer. Connect it with a Y connector, and once you move the dial over, check the pressure at several readings on both meters to make sure the aneroid manometer matches the mercury manometer.
Pick a cuff that is an appropriate size
Larger patients will need larger cuffs; otherwise, their blood pressure will read higher than it actually is. Similarly, smaller patients will need smaller cuffs; otherwise, their blood pressure will read lower than it actually is.
Wrap the cuff around the patient’s arm
Wrap the cuff of the manometer snugly around the patient’s exposed upper arm. The bottom edge of the cuff should be approximately one inch above the bend of the elbow.
Pump air into the cuff.
This step should be done quickly. You should let the cuff reach a point where you can’t feel the radial pulse anymore. Note the pressure in mmHg. That pressure is a general guide for the systolic pressure.
Take the air out of the cuff.
Release the air from the cuff. Add 30 mmHg to your previous reading. That is, if you lost the pulse at 120 mmHg, add 30 to reach 150 mmHg.
Place the stethoscope bell on the brachial artery
You should hold the bell of the stethoscope on the patient’s skin just below the edge of the cuff. It should center on the brachial artery so that you can hear the blood flow.
Re-inflate the cuff.
Add air into the cuff rapidly, until it reaches the number you found by adding 30 mmHg. Once you’ve hit that number, stop adding air.
Slowly let the air out
Let the air deflate from the cuff at a rate of 2 to 3 mmHg a second. While it is deflating, make sure you are listening in the stethoscope.
Record the measurements.
Write down the high and low numbers, as well as what size cuff you used. Also, write what arm was used and the position the patient was in.