News - Hypertension Week of Jan. 11, 2004/ Vol. 3 No. 02

Study: Arm Position Matters in Accurately Measuring Blood Pressure

Arm position matters when it comes to getting an accurate blood pressure reading, according to University of California at San Diego medical researchers.

The right way to measure blood pressure is to have patients bend their elbow at a right angle to the body with the elbow flexed at heart level, according to a study reported in the January 6 issue of the Annals of Internal Medicine.

Researchers found that blood pressure readings taken on arms parallel or extended in the same direction as the body are up to 10 percent higher.

They added that a previously published study found that 73 percent of health care workers failed to use proper arm and blood pressure cuff positions.

Lead researcher Dr. David Guss, a University of California at San Diego professor of medicine, and his colleagues measured blood pressure in 100 emergency room patients between the ages of 18 to 88 who were being seen for a primary symptom unlikely to be associated with cardiovascular instability.

The patients' blood pressure was measured six times -- with the elbow bent at a right angle to the body or parallel to the body while laying, sitting and standing. The proportion of seated patients classified with high blood pressure was 22 percent with the arm perpendicular and 41 percent with the arm parallel to the body.

"In every body position, the systolic and diastolic blood pressure measured with the arm perpendicular to the body was significantly lower than with the arm in a parallel position," the researchers said.

Other sources: UCSD