A blood pressure cuff is otherwise known as sphygmomanometer. It is an instrument that measures the blood pressure by holding up the flow of blood in the artery for a few seconds. Blood pressure (BP) is the force exerted by the blood upon the walls of the blood vessels especially the arteries. The usual location to where blood pressure is measured is at the brachial artery located at the medial side of the cubital fossa (shallow crease between the forearm and upper arm). The normal blood pressure is 120/80, where 120 serves as the systolic pressure, and 80 as the diastolic pressure.Systolic blood pressure is the highest arterial pressure of the cardiac cycle, when the heart is pumping blood to the body; while diastolic blood pressure is the lowest arterial blood pressure, when the heart is at rest. Measuring your blood pressure with a blood pressure cuff is a convenient way to do it, especially at home. Its use is essential to monitor the stableness of your blood pressure and overall health.
Prepare your instruments prior to starting he actual procedure. Completely deflate the cuff before using it again. Clean the ear pieces with an alcohol wipe if you are using somebody else’s stethoscope. A stethoscope is an instrument used to auscultate or detect sounds produced by the body (such as heartbeat and pulse).
Ask the patient to sit or lie comfortably, with one arm properly resting on the table or bed side. Let the patient supinate (palms and arms facing upward) to expose the brachial artery situated on the medial side or inner side of the cubital fossa (shallow crease between the forearm and upper arm).
Wrap the cuff around the upper arm of the patient just slightly above the elbow or cubital fossa. Make sure to leave an inch of space above the level of the cubital fossa. Close the Velcro strap around the upper arm to secure the cuff. Fit it snugly--snug enough that you can slip one finger in between the cuff and the upper arm. Position the dial gauge in an area where you can clearly see its pointer if you are using an aneroid sphygmomanometer.
Place the ear pieces of the stethoscope in your ears, and position the disk of the stethoscope on the inner or medial side of the arm, slightly above the cubital fossa. Secure the disk in place by holding it firmly with your thumb.
Use your other hand to grip on to the inflating or rubber bulb of the sphygmomanometer; hold it firmly on your palm so that your fingers can easily maneuver its air control valve as you inflate and deflate the cuff during the process.
Squeeze the rubber bulb rapidly to inflate the cuff. Keep an eye on the pointer of the dial gauge. Watch it closely as it moves clockwise and then stop squeezing when it reaches 150. Remember to do a brisk squeeze of the bulb to ensure an accurate measurement. If you are taking the blood pressure of the same person, you can squeeze the bulb up to 30 points higher than her last systolic reading. When measuring a child’s blood pressure, there is no need to squeeze the bulb up to 150.
Set your fingers to turn and loosen the valve to allow some air out of the cuff. It is important to not let the air out too suddenly or you may end up not getting the right blood pressure of the patient. Do it gradually but not really too slow either. Deflate the valve for about two to three millimeters per second.
Pay attention to the sound in your stethoscope. As you go on deflating the cuff, listen very carefully to the first sound in your stethoscope and get your eyes fixed on the pointer of the dial gauge as it falls counterclockwise. When you hear the first sound, you will also see the pointer of the dial gauge jerk slightly on a certain number at the same time. This number serves as the systolic pressure.
Continue deflating the cuff and keep your eyes fixed on the dial gauge. The sound is still there until it stops. Now take note of the number to where the pointer is leveled, after hearing the last sound or the point where you stop hearing the heartbeat--this last sound will be the diastolic pressure.
Open the valve completely to allow the remaining air out of the cuff. And then record the patient's blood pressure, putting the systolic pressure over the diastolic pressure. For example: BP 120/80.
If you want to repeat your measurement on the same person, wait at least three minutes before doing the procedure again. As much as possible, allow the patient to rest for a few minutes before taking her blood pressure in order to ensure an accurate result. If it is quite impossible to take the blood pressure on the arms, you can use the leg to measure it. The usual site on the leg is at the popliteal fossa (the space at the back of the knee) to where the popliteal artery is situated.