Interarm differences in blood pressure should be determined by measuring both arms simultaneously with an automatic oscillometric device

Objective To compare two methods for screening interarm difference (IAD) of blood pressure. Material and methods This study compared two methods for double-arm measurements: (i) conventional measurement (CM) and (ii) simultaneous automatic measurement (SAM). A total of 118 patients with two or more cardiovascular risk factors and a mean age of 59 +/- 17 years were referred to two internal clinics. CM was taken with a validated aneroid manometer in sitting position on the right and left arm subsequently and vice versa. SAM was taken three times in sitting position using a validated automatic oscillometric device equipped with two cuffs for simultaneous double-arm measurements. Results The average absolute IAD of the conventional systolic value (4.9 mmHg) was significantly higher than the average absolute IAD of the SAM pressures averaged from two (3.7 mmHg; P < 0.03) and three measurements (3.8 mmHg; P < 0.05). The standard deviations of IADs were significantly higher (P < 0.05) for the conventional systolic and diastolic measurements (4.1/3.1 mmHg) than for SAM averaged from two and three (3.0/2.3 and 3.2/2.6 mmHg, respectively) measurements. Differences of more than 20 mmHg for systolic pressure and/or 10 mmHg for diastolic pressures averaged from two CMs, two SAMs, and three SAMs were seen in 10 (9%), four (3%), and six (5%) patients, respectively. Conclusion SAM provides smaller and more reproducible IADs than CM and therefore, most likely better estimates a patient's true IAD. Blood Press Monit 16:37-42 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.