Many patients may not understand the numbers provided in a blood pressure reading. The pharmacist should educate the patient about what these numbers mean, not just the goal ranges. The pharmacist should explain that blood is carried from the heart to all parts of the body in arteries and veins. Blood pressure is the force of the blood pushing against the walls of the arteries at different times during the heartbeat. Each time the heart contracts, the blood is pushed out of the heart and into the arteries. When the heart is contracted, the pressure against the artery walls is the highest. This is called the systolic blood pressure. When the heart relaxes to allow the blood to refill the heart, the pressure against the arteries is lowest. This is called the diastolic blood pressure. Typically this cycle occurs 60 to 70 times a minute, unless the individual is moving, and then the rate is higher.

When we read a blood pressure, two numbers are provided—the systolic and diastolic pressures. Typically they are written one number above or before the other, such as 120/80 mmHg. Often the units of mmHg are omitted but are understood to be the units that we are measuring. The top, or first, number is the systolic blood pressure. The bottom, or second, number is the diastolic blood pressure. When reading the numbers, they are read as “120 over 80.”

Before taking a blood pressure reading, the person should be seated quietly for at least five minutes. Ideally, the patient should avoid smoking or drinking caffeinated beverages for 30 minutes prior to the blood pressure reading. The person’s feet should be on the floor. The arm used for the reading should be supported and at heart level. The patient should not be holding the arm at this level, rather it should be resting on a table or other support. The patient’s efforts to hold up the arm can falsely raise the reading. If the arm is much lower than heart level, blood pressure readings appear falsely elevated.

An appropriate-sized cuff should be used to ensure accuracy. The width of the inflatable bladder of the cuff should be approximately 40 percent of the upper arm cir-

cumference, approximately 12 to 14 centimeters in the average adult. The length of the cuff bladder should encircle at least 80 percent of the arm, almost long enough to encircle the arm. Cuffs that are too short or too narrow may give falsely elevated readings. The use of a regular-size cuff on an obese arm may lead to a false diagnosis of hypertension or misclassification of the stage of hypertension.

 

STRESSING THE IMPORTANCE

OF HOME MONITORING

Unfortunately, many patients with hypertension do not consider regular blood pressure monitoring to be a routine part of controlling hypertension. However, studies show that home blood pressure monitoring can improve blood pressure control. ¹⁷

In a study of 430 patients, the patients who performed self-monitoring were more likely to reach blood pressures that allowed them to stop their antihypertensive medications or that allowed treatment to remain stable. Those who performed home monitoring, on average, used one drug or one drug less than those who did not perform home monitoring. The cost of medicine in the home monitoring patients was more than $1,000 less per 100 patients for one month of treatment. Although this study found that these patients had no more organ damage than those whose pressures only were measured in the physician’s office, other studies have shown that home monitoring can reduce the risk of organ damage or heart complications.

A Joint Scientific Statement from the American Heart Association, the American Society of Hypertension and the Preventative Cardiovascular Nurses Association expressed strong support for home blood pressure monitoring. Recommendations included home blood pressure monitoring becoming a routine component of blood pressure measurement in the majority of patients with known or suspected hypertension and that home blood pressure monitoring is indicated in patients with newly diagnosed or suspected hypertension, patients with perhypertension. It is also considered to be useful in the elderly as well as patients with diabetes and kidney disease. ²³

Self-monitoring of blood pressures allows patients to play an active role in their care. They can feel empow-

ered to maintain lifestyle modifications and to adhere to medication therapy. The opportunity for patients to be involved in this manner is relatively new. Historically, blood pressure measurement was limited to the doctor’s office. Technological advances, however, have enabled the development of instruments that can be used at home easily.

The mercury sphygmomanometer has long been considered the “gold standard” for measurement of blood pressure. However, for many reasons, including risks of mercury contamination, the mercury sphygmomanometer is becoming less prevalent even in doctors’ offices. Automated oscillometric blood pressure devices are among those devices being used in medical offices instead of mercury sphygmomanometers. Most home blood pressure monitors also use a type of automated oscillometric measurement. However, one company has introduced home monitoring technology that uses the auscultatory method, in which a built-in microphone listens to sounds in the arterial wall.

Most pharmacies now sell automated and semi-automated blood

pressure machines. While it is possible to purchase models with a pump for manual inflation of the cuff, fully automated models are very popular due to their ease of use. When using one of these models, the patient simply puts on the cuff, presses a button and waits for the reading. These devices usually provide a large read-out display for easy reading of the measurement. Indeed, products currently on the market offer a wide variety of features. The pharmacists should be prepared to help the patient understand the various features and assist in the selection of a product that best meets the individual’s needs.

As mentioned already, many monitors display results in large numbers. Of course, some patients may not be interested in large numbers and instead prefer a monitor that takes up the smallest amount of space possible for easy storage. Preference for wrist versus arm monitor also is an individual choice. Some prefer the arm models, perhaps because they look more like the ones patients have seen in the doctor’s office. Regardless of whether an arm or

PATIENT SCENARIO 4

Patient Case

Mrs. Smith, the 60-year-old patient who was discussed in a previous case, approaches the pharmacy counter and informs the technician that she has an appointment with the pharmacist to review her medication therapy. When the pharmacist and Mrs. Smith move to the counseling room, the pharmacist begins to review her medication profile and medical history. Mrs. Smith has a history of diabetes, obesity and hypertension. Mrs. Smith offers her log of blood glucose readings to the pharmacist for review. She proudly reports that her glucose readings have been improved since her last visit. The pharmacist asks her if she has a log of blood pressure readings as well. Mrs. Smith appearing confused asks the pharmacist, “Why would I check my blood pressure? I go to the doctor’s office every six months, and he always checks it.”

Discussion

For patients with diabetes, checking blood glucose readings multiple times a day is routine. Patients recognize the importance of controlling glucose levels in the prevention of long-term complications, such as kidney disease, nephropathy, cardiovascular disease, retinopathy and neuropathy. These glucose readings are utilized to determine the need for extra doses of insulin throughout the day or to adjust overall therapy.

For patients with asthma, the routine checking of peak flow readings also is standard practice. The evaluation of peak flow readings allows the patient to notice declines in lung function before symptoms develop. At the beginning of therapy, “green zones,” “yellow zones” and “red zones” are established based on the patient’s own lung capacity. Even though the patient may not yet notice a decline in lung function, a drop in function into the yellow or red zones requires alterations in the treatment plan until lung function improves.

Most patients with high blood pressure do not consider routine testing of blood pressure to be as essential. The pharmacist can play a critical role in correcting this misconception.