How Do BP Cuffs affect Blood Pressure Monitoring
When taking blood pressure measurements, we usually emphasize how patients have to do to get an accurate reading. Seldomly, we talk about the cuff’s effect on the blood pressure reading. If we choose the wrong cuff size, it leads to the wrong BP level measurement.
What is Blood pressure cuff?
The blood pressure cuff is a vital part of blood pressure measurement. It is a sleeve with an air bladder that is inflatable in it. Wrapping it on the upper arm and pumping air into the bladder would compress the artery to complete the BP measurement.
Types of the blood pressure cuff
According to the cuff structure, we can divide the cuff into bladderless cuff (or one-piece cuff) and bladder cuff (also, we say cuff with inflation bag). The bladderless cuff puts the air bladder and cuff together, which is more compact in design and easy for carrying, while the bladder cuff has two pieces separately, the nylon cuff and PVC bladder. The bladder can be replaced when it is broken.
By how many patients use, there are reusable NIBP cuffs, and single patients use disposable cuffs. The reusable cuff is for different patients. Thus, we have to disinfection after use to prevent cross-inflection. The single patient uses cuff only for one patient in the hospital. We do not have to worry about cross-infection as it is discarded after one patient uses it. The disposable cuffs are usually for patients with poor immunity or easy to get infected, such as those in ICU, NICU, emergency room, etc.
Even though we have the cuffs in different types, they only help the medical staff to choose the proper cuff for patients. They have no affection on the measurement result.
How to get an accurate blood pressure reading?
The cuffs for the upper arm measurement provide the most precise blood pressure reading. To get the accurate measurement, we have to choose the right size of BP cuff and place it in the proper positioning.
How to choose NIBP cuff size?
Before choosing the blood pressure cuff size, we need to know our upper arm circumference because it is related to the cuff size. The wrong size cuff would lead to misreading.
To avoid the wrong size causing too high or low blood pressure reading, the length of the bladder is no less than 80% of the circumference, and the width is more than 40% of the circumference.
If the bladder is less than 80% of the upper arm circumference, it may lead to the bladder cannot cover the artery and an over-inflated bladder causes higher readings. And if a too large BP cuffs over the arm with overlapping, which is easier to compress the artery with smaller air in the bladder and cause a lower blood pressure reading. That is to say. With the same size BP cuff, for the thinner arm, less air in the bladder can stop the artery blood flow, which leads to lower blood pressure. And for the fatter arm, we need more air to stop it, and it causes higher blood pressure.
The AHA recommendation cuff size for blood pressure measurement
|
PATIENT |
RECOMMENDED CUFF SIZE（width*Length） |
|
Adults (by arm circumference) |
|
|
22 to 26 cm |
12 × 22 cm (small adult) |
|
27 to 34 cm |
16 × 30 cm (adult) |
|
35 to 44 cm |
16 × 36 cm (large adult) |
|
45 to 52 cm |
16 × 42 cm (adult thigh) |
|
Children (by age) * |
|
|
Newborns and premature infants |
4 × 8 cm |
|
Infants |
6 × 12 cm |
|
Older children |
9 × 18 cm |
The cuff tightness and positioning on blood pressure measurement
Right cuff size is the precondition to get an accurate blood pressure measurement. We also consider the proper tightness and suitable positioning if we want a precise BP reading.
When measuring blood pressure, the tightness of the cuff should be appropriate. It is better to leave space where allow one finger to insert in, and the position of the cuff should be 2-3cm to the elbow.
If the cuff is too tight, the measured blood pressure is lower than the actual blood pressure; if the cuff is too loose, the blood pressure measurement is higher. The principle is that when the airbag is too tight, less inflation (pressure in the cuff) can block the arterial blood flow, so the measured blood pressure is low. On the contrary, when the air bladder is too loose, it is inflated more than normal needed, and the blood pressure reading is higher than the actual blood pressure.
If the cuff position is too low, covering the elbow joint, the measured blood pressure is higher than the actual blood pressure. It is because of the low positioning, the air bladder that compresses the brachial artery becomes narrow. Thus, more inflation is needed to block the arterial blood flow, and the measured blood pressure is higher than the actual blood pressure.
Therefore, if we want to have accurate blood pressure reading, we have to choose the right-sized cuff and placing the cuff correctly.
NIBP
As the most famous manufacturer of patient monitoring accessories in China, Unimed Medical Supplies specializes in providing customers with one-stop solutions for monitoring accessories. Our flexible manufacturing method can quickly customize the products that customers need to serve hospitals and patients in all countries around the world.
If you are interested in our blood pressure cuffs or have any questions about unimed medical, feel free to contact our sales manager or email to sales@unimed.cn for more detailed information. Any of your business requirements will be highly appreciated.
Unimed Medical Supplies Inc.
Address: Bld#8, Nangang 3rd Industrial Park, Tangtou, Shiyan, Shenzhen, China,518108.
E-Mail: sales@unimed.cn
Website: http://www.unimed.cn
