Helping Patients Select Blood Pressure Monitors

Author: Yvette C. Terrie, BSPharm, RPh

Pharmacists are in a unique position to inform patients about the various features and proper use of blood pressure monitors.
In the United States, an estimated 74.5 million individuals, or 1 of 3 individuals aged 20 years and older, are considered to have hypertension.1,2 Among the patient population diagnosed with hypertension, only an estimated 77.6% are currently being treated. Of those receiving treatment, only 44.1% have their blood pressure (BP) under control. 1 Furthermore, an estimated 25% of American adults are classified as being prehypertensive.2

Hypertension is often referred to as the “silent killer,” because, if left untreated or uncontrolled, elevated BP can ultimately lead to strokes, myocardial infarctions, heart failure, renal failure, and increased risk of morbidity and mortality.3,4 The mortality rate related to hypertension between 1996 and 2006 increased 25.2%, and the actual number of deaths increased 48.1%.1

The risk factors associated with hypertension can be classified as modifiable or nonmodifiable. Patients with hypertension or those at risk for hypertension should be encouraged to discuss these factors (Table 1) and recommended BP levels with their primary health care provider.5,6

Table 1

A reliable and accurate monitor is an essential tool for keeping track of one’s BP. Pharmacists are likely to encounter patients seeking guidance regarding the selection of BP monitors. They are also in a pivotal position to inform patients about the specific features of the various models of BP monitors available and ensure that patients are adequately counseled on the proper use of these devices.

At-home monitoring of BP may be especially beneficial for the following patient populations6:
• Patients initiating therapy with antihypertensive agents, to determine effectiveness of therapy
• Patients requiring closer monitoring than intermittent physician office visits (ie, patients with coronary heart disease, diabetes, and/or renal disease)
• Pregnant women, since preeclampsia or pregnancy-induced hypertension can develop rapidly
• Patients who have some elevated BP readings at the doctor’s office, to rule out “white-coat syndrome” and confirm true high BP
• Elderly patients, because the whitecoat effect increases progressively with age
• Patients suspected of having masked hypertension
• Patients with risk factors associated with hypertension

Types of At-Home BP Monitors

There are 3 types of BP monitors: mercury column, aneroid, and digital.4  Aneroid and digital monitors are the 2 types of monitors most commonly used for athome monitoring of BP.1,4

Aneroid monitors are light, portable, and considered to be very affordable. It is imperative that patients are educated on the use of these more traditional manual monitors and clearly understand the testing procedure in order to obtain accurate results.4 Many aneroid monitors come with a stethoscope attached to the cuff, which frees the patient from having to hold the bell of the stethoscope in place.4 A few monitors also have the gauge attached to the inflation bulb, which allows for easier handling.4

The accuracy of readings with standard aneroid monitors is dependent upon various factors, such as good eyesight, hearing, and dexterity.4 For those patients with decreased vision, there are aneroid meters available with large print on the face of the gauge for easier reading.4 Patients electing to use aneroid meters should be informed that when a cuff is completely deflated and lying on a table, the needle of the gauge should rest in the box. If the needle lies outside the box, the gauge needs to be recalibrated. In that case, they should contact the manufacturer of the device for instructions on recalibration or contact their primary health care provider.4,6

Digital monitors are very popular among consumers because of their ease of use and are available for the upper arm or the wrist. When recommending an arm monitor, pharmacists should stress the importance of selecting a device with the proper cuff size to accommodate the circumference of the upper arm in order to obtain accurate results.4,6 Many arm monitors are available in a variety of cuff sizes.

Although wrists monitors are compact and portable, some studies suggest that wrist monitors may not be as accurate as upper arm monitors, and errors may occur due to differences in the positioning of the wrist relative to the heart when measuring.4,6 The American Heart Association recommends an automatic cuff-style upper arm monitor and does not recommend wrist monitors, because the brachial artery in the upper arm gives a more reliable reading than the artery in the wrist.4,6,7

Factors that may be considered in the selection of a home BP monitor include cost, cuff size, ease of use, patient preference, memory features, large digital display, reliability, and accuracy.2,4 Some monitors have cuffs that inflate and deflate by the push of a button, although manual BP monitors are still available. Many monitors have the ability to store several readings, large display screens for easy reading of the results, the ability to print out results, irregular heartbeat detectors, and pressure rating detection.

Ensuring Proper Use

During counseling, pharmacists can convey to patients that monitoring BP can be easily incorporated into one’s daily routine and that regular monitoring is crucial for the overall control of their BP. Pharmacists can further assist patients by ensuring that they clearly understand the proper protocol for utilizing these monitors, as well as factors that may affect the accuracy of results, such as stress, smoking, and the use of beverages containing caffeine.2 Tips for self-monitoring of BP are presented in Table 2.

Table 2

During counseling, pharmacists should remind patients about the serious consequences associated with uncontrolled BP, as well as the importance of adhering to treatment protocol and the recommended BP levels.

Patients should be encouraged to always discuss the results of BP readings with their primary health care provider, especially if they obtain elevated readings. Patients should also immediately seek medical care if their BP readings are elevated and/or they are experiencing blurred vision, headaches, and dizziness. PT

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.