Scientists from Ohio State University decided to check how the value of measured pressure changes depending on how and on what the patient sits. The differences turned out to be significant for the possible diagnosis of hypertension.
According to the guidelines of scientific societies (including the American Heart Association), blood pressure should always be measured in the appropriate position. The patient should sit upright in a chair, with his feet on the ground, his back supported, and his arm with the blood pressure cuff resting on the level of his heart. It turns out, however, that even in medical offices this is not always observed and the blood pressure is measured in patients who, for example, are sitting on treatment tables with their legs hanging down freely. That’s why scientists did an experiment that showed that the right position is crucial for correct measurement.
How does position affect the blood pressure result?
Researchers from Ohio State University measured blood pressure in the same volunteers sitting in various positions – including on a table and in a chair. It turned out that the place of measurement is so important for the result that it may cause an incorrect diagnosis.
When readings were taken on an examination table, the systolic blood pressure (top number) was 7 mm Hg higher and the mean diastolic blood pressure (bottom number) was 4.5 mm Hg higher compared to readings taken while sitting and maintaining the recommended position.
“We weren’t surprised there was a difference. We were surprised that it was so large,” said Dr. Randy Wexler, one of the study’s authors. The researchers concluded that the difference in the measurements was so significant that they believed it could cause millions of people to be misclassified as having high blood pressure.
An important appeal from scientists regarding blood pressure measurement
The authors of the study pointed out that medical services admit so many patients every day that there is often no time to think about the recommended position when measuring blood pressure. However, scientific experiment shows that this should not be underestimated and care should be taken to ensure that the pressure is actually measured in the position specified in the guidelines.