12 tips to ensure you get the most accurate BP measurement
There’s a lot to taking a blood pressure measurement properly, according to a 90-page scientific statement just released by the American Heart Association.
Here are 12 tips from their statement titled Measurement of Blood Pressure in Humans.
- Use an automated oscillatory sphygmomanometer over the traditional auscultatory technique – it’s more accurate. Ideally use one that allows multiple readings with one activation.
- Make sure the patient has emptied their bladder.
- Leave the patient sitting quietly in a chair for 3-5 minutes before taking their BP
- Use a cuff with a length equal to 75-100% of the patient’s upper arm circumference (which is measured halfway between the olecranon and the acromium). Using too small a cuff in a large person is the most frequent mistake measuring BP in the office, leading to elevated readings.
- Put the cuff on bare skin.
- Avoid rolling up short sleeves as it can produce a tourniquet effect.
- Better results are obtained if the patient is alone with the machine. If someone is with the patient, there should be no conversation while the measurements are being taken.
- Sitting on an examination table can increase systolic BP by 5-15mmHg because the patient has no back support.
- If the patient has their legs crossed, their systolic BP may be raised by 5-8 mmHg.
- For a first reading, measure BP in both arms and then use the arm that had the higher measurement for subsequent measurements. Arms can often differ by 10mmHg, a clinically significant amount.
- Take at least two measurements at a visit. Use an average of measurements from at least two visits to determine the patient’s BP.
- Tell the patient their BP, explain what it means, and write it down for them.
More information: Hypertension 2019.