“Our findings suggest either device can be used to accurately measure blood pressure,” Dr. Amy S. Shah from Cincinnati Children’s Hospital, University of Cincinnati College of Medicine, Cincinnati, Ohio told Reuters Health in an email. “When compared to mercury sphygmomanometers, the differences are small and are unlikely to be clinically significant.”
Aneroid sphygmomanometers are rapidly replacing mercury-filled devices for blood pressure measurement as a result of safety and environmental concerns about mercury, but few studies have compared the two devices.
Dr. Shah and colleagues compared mercury and aneroid systolic and diastolic blood pressure measurements in 193 youth (aged 3.9 to 18.9 years) who had a mean duration of diabetes of 9.2 months. Their findings appear in the April 16 online issue of Pediatrics.
Overall, there was a 94% correlation between mercury and aneroid measurements of systolic blood pressure and an 82% correlation for diastolic blood pressure.
Among individuals under age 10 years, there was no significant difference in systolic and diastolic blood pressure measurements with the two types of sphygmomanometer.
Among individuals between 10 and 18 years old, there was no significant difference in systolic blood pressures, but the diastolic blood pressure averaged 1.8 mm Hg lower with aneroid devices than with mercury devices.
“Thus,” the researchers note, “to equate blood pressures between devices a correction factor of +1.8 could be added to an aneroid blood pressure measurement in individuals 10 years and older.”
Diastolic blood pressures were slightly higher in nonwhites and in children with increasing body mass index z score, but in fully adjusted models, no predictors explained the difference in the diastolic blood pressure measures with the two devices.
“Our findings suggest, despite mercury sphygmomanometers being the gold standard, aneroid devices are an accurate alternative,” Dr. Shah concluded. “There is little clinical variation between blood pressures taken between the two devices, suggesting either device could be used in a research or clinical setting.”