To improve clinic efficiency, blood pressure (BP) kiosks have been installed in the clinic waiting room. After check-in, patients are instructed to self-measure their BP at the kiosk and present a printout of the BP result to the clinician.
A 25-year-old man with class 3 obesity and type 2 diabetes mellitus obtains a reading of 152/87 mm Hg in the waiting room. He has never had a BP that high in the past and denies any symptoms.
He is concerned because his father died at 50 years of age of a myocardial infarction. He requests initiation of an antihypertensive medication.
Initiation of an antihypertensive medication is warranted due to the severity of his BP elevation, risk factors, and family history.
Show Answer
The correct answer is: Fiction
Although kiosk devices have many potential advantages, such as improving access to care, low cost, and convenience, there are limitations to these devices that should be kept in mind. By design, these devices are typically "arm-in" devices, meaning that they have one cuff designed to accommodate a specific mid upper arm size, surrounded by a hard casing. BP measurements are often self-obtained: the patient sits in front of the device, puts their arm in the cuff, and pushes a button to obtain a measurement.
For kiosk BP measurements to be optimally accurate, patients should rest for 3-5 min before measurement, they should be seated in a chair that supports their back and allows both feet to be placed on the ground, and the kiosk device should be positioned so the middle of the cuff is at mid heart level.1 Ensuring that the cuff is appropriately sized for the patient and that the patient inserts their arm fully to allow the device to compress their brachial artery without any interference by their elbow being inserted in the cuff are also essential.
Public-use kiosks may not allow for proper positioning in all patients (i.e., short or tall individuals may have the cuff positioned above or below their mid heart level), and many have narrow cuff sizes (commonly 22-42 cm, with some only accommodating arms that are 22-38 cm in circumference).2,3 This limitation can lead to miscuffing and measurement error in a significant number of adults in the United States. Recent National Health and Nutrition Examination Survey (NHANES) data revealed that 0.3% (800,000) US adults have arm circumference <22 cm and 6.4% (15.8 million) have arm circumference >42 cm.4 Kiosk devices with narrow cuff ranges would not be appropriate for use in these individuals: those with arm circumferences <22 cm could obtain a reading that underestimates their BP by 3.6/1.3 mm Hg, and those with arm circumference >42 cm could obtain a reading that overestimates their BP by up to 19.5/7.4 mm Hg.5
Further, the public setting (e.g., a clinic waiting room) does not typically allow for 3-5 min of rest and does not often offer a quiet environment. Resting for >3 min is particularly important for measurement accuracy for patients with high BP.6
Therefore, for this individual, BP should be remeasured with a validated device that has a cuff appropriately sized for his measured mid arm circumference prior to clinical decision making.
This patient case quiz is part of the larger Overcoming Challenges in Hypertension Management grant. Educational grant support is provided by Medtronic. To visit the Overcoming Challenges in Hypertension Management grant page and access additional educational activities on this topic, click here.
References
Muntner P, Einhorn PT, Cushman WC, et al.; 2017 National Heart, Lung, and Blood Institute Working Group. Blood pressure assessment in adults in clinical practice and clinic-based research: JACC scientific expert panel. J Am Coll Cardiol 2019;73:317-35.
Stride BP. Validated blood pressure monitors (Stride BP website). 2024. Available at: https://stridebp.org/bp-monitors. Accessed 03/01/2024.
Alpert BS. Validation of the Pharma-Smart PS-2000 public use blood pressure monitor. Blood Press Monit 2004;9:19-23.
Jackson SL, Gillespie C, Shimbo D, Rakotz M, Wall HK. Blood pressure cuff sizes for adults in the United States: National Health and Nutrition Examination Survey, 2015-2020. Am J Hypertens 2022;35:923-8.
Ishigami J, Charleston J, Miller ER 3rd, Matsushita K, Appel LJ, Brady TM. Effects of cuff size on the accuracy of blood pressure readings: the Cuff(SZ) randomized crossover trial. JAMA Intern Med 2023;183:1061-8.
Brady TM, Charleston J, Ishigami J, Miller ER 3rd, Matsushita K, Appel LJ. Effects of different rest period durations prior to blood pressure measurement: the Best Rest trial. Hypertension 2021;78:1511-9.