25

devices can be used for self measurement of blood pressure. At present, there are no published protocols or minimum standards for community-based evaluations of automated blood pressure measuring devices designed for community use (Lewis, Boyle, Magharious & Myers, 2002). Community-based automated devices are not recognized in the current diagnostic algorithm for hypertension nor are they included in the recommendations for self blood pressure monitoring. The Vita-Stat 90550, an automated device located in approximately 3,000 Canadian community settings, did not meet the BHS or AAMI criteria for accuracy during testing in a research study (Lewis et al., 2002). Other potential problems with community based devices are that the cuff size (22 x 33 cm) is inadequate for clients with large arms and the devices are not labeled to show when and if there has been recent maintenance and revalidation of the device’s performance (Pickering et al., 2005). Further research is needed to validate these devices before they will be endorsed for diagnosis and monitoring of blood pressure in routine practice. Nursing Best Practice Guideline Nursing Management of Hypertension 36 Figure 3: Important points about self/home blood pressure monitoring Considerations when purchasing a monitor: ■ The cost of the monitor is usually between $80-140. ■ Choose a device that meets the standards of the Association for Advancement of Medical Instrumentation (AAMI), the British Hypertension Society (BHS) or International Protocol (IP). Look for this trademark symbol* on the package. *Endorsed by the Canadian Coalition for the Prevention and Control of Hypertension ■ Choose the right cuff size – the bladder of the cuff should cover 80% of the upper arm. ■ To increase the reliability of reported self/home blood pressure values, purchase devices that automatically record data. ■ Ask a healthcare professional if you require assistance. Important points about measuring blood pressure at home: ■ Clients should read the instructions that come with the monitor carefully. ■ Clients should be observed to ensure that blood pressure is measured correctly. Inform clients of the following: ■ No smoking or nicotine 15-30 minutes before taking blood pressure. ■ No caffeinated beverages one hour before taking blood pressure. ■ Rest for 5 minutes before taking blood pressure. ■ Sit up straight with the back supported. The arm should be supported so the elbow is just below heart level. ■ Never cross the legs when measuring blood pressure. ■ Do not talk while measuring blood pressure. ■ Check blood pressure twice in the morning (before taking medications) and twice in the evening for seven consecutive days. ■ Bring blood pressure device and record with you to your next appointment. ■ Stable, normotensive clients should check blood pressures for a one-week period every 3 months. Persons with diabetes, or clients having difficulty following a treatment plan, should check their blood pressure more frequently. ■ Home monitors should be checked annually against a device of known calibration. This would require a visit to the clinic to have a blood pressure check using the home equipment and calibrated clinic equipment for the purposes of comparison.