Use of one-size cuff tied to major inaccuracy in BP readings across varying arm sizes

Accurate blood pressure (BP) measurement is crucial for diagnosing and managing hypertension, a significant risk factor for cardiovascular disease. Clinical guidelines recommend selecting an appropriately sized BP cuff based on mid-arm circumference to ensure accurate readings. However, the impact of using an incorrect cuff size with automated BP devices has not been thoroughly studied. A recent randomized crossover trial published in JAMA Internal Medicine by Junichi Ishigami and a team of researchers aimed to quantify the effect of miscuffing on BP measurements.

Conducted between March 16 and October 25, 2021, in Baltimore, Maryland, the study enrolled 195 community-dwelling adults with varying mid-arm circumferences. Participants underwent four sets of triplicate BP measurements, with three sets using a regular, too-small, or too-large BP cuff in random order, and the fourth set using an appropriate cuff. The primary outcome was the difference in mean BP between regular and appropriate cuff sizes, and the secondary outcome assessed the impact of using incorrectly sized cuffs across all sizes.

● Out of the 195 participants (mean age: 54 [SD 16] years; 67 [34%] male; 132 [68%] Black; 100 [51%] with hypertension), 24,815 (33.4%) had metabolic syndrome (MetS), and 2,032 (2.7%) had kidney stones.

● Among those requiring a small cuff, using a regular cuff yielded a statistically significant lower systolic BP reading (mean difference: -3.6 [95% CI, -5.6 to -1.7] mm Hg).

● Individuals requiring large or extra-large cuffs experienced significantly higher systolic BP readings with a regular cuff (mean difference: 4.8 [95% CI, 3.0-6.6] mm Hg and 19.5 [95% CI, 16.1-22.9] mm Hg, respectively).

● Stratified analyses revealed consistent trends by systolic BP and BMI categories.

● In terms of secondary outcomes, overcuffing and undercuffing by one or two cuff sizes had a more pronounced impact on BP readings among participants requiring larger cuffs.

● When compared with the reference quartile (median steps/day 3967), higher quartiles of steps/day (Q1 = 3982, Q2 = 6661, and Q3 = 10,413) exhibited a linear association with reduced risk of cardiovascular (CV) mortality (16, 49, and 77%; P < 0.05, for all).

The study's results underscore the substantial influence of cuff size on the accuracy of BP measurements. Using an appropriately sized BP cuff is crucial to ensure reliable and precise readings. These findings call for a reevaluation of cuff sizing practices in clinical settings, emphasizing the importance of individualized cuff selection for accurate BP assessment, proper hypertension diagnosis, and effective management.

Reference:

Ishigami, J., Charleston, J., Miller, E. R., III, Matsushita, K., Appel, L. J., & Brady, T. M. (2023). Effects of cuff size on the accuracy of blood pressure readings: The cuff(SZ) randomized crossover trial. JAMA Internal Medicine. https://doi.org/10.1001/jamainternmed.2023.3264