Undiagnosed OSA increases the risk of high blood pressure

Obstructive Sleep Apnoea (OSA) is a sleep related breathing disorder which occurs if airflow through the nose and mouth is obstructed. Having undiagnosed OSA increases the risk of high blood pressure, and is associated with other serious conditions such as strokes and heart attacks, type II diabetes and depression as well as traffic collisions. OSA affects men, women and children.

A growing amount of evidence suggests that OSA is the most common type of secondary hypertension, however, an estimated 70-90 percent of cases are undiagnosed.

The Meditech apneABP is ideal as an opportunistic outpatient screening tool for OSA and can help diagnose at risk patients prior to referral to specialist sleep labs.

Blood pressure is recorded automatically at pre-set intervals and SP02 data is recorded continuously.

The easy to use CardioVisions software displays 24-hr blood pressure chart, histogram, correlations, blood pressure statistics, oxygen saturation overview, plethysmograph pulse wave, pulse oximetry statistics and activity.

As a result, apneABP gives information not only about blood pressure and general pulse oximetry data, but also about the condition of the arterial system through plethysmograph and pulse wave.

The apneABP e will allow CCGs and GPs to take an active role in OSA screening and referral pathways which is beneficial to the patient, the GP and the sleep clinic.

PMS algorithm for blood pressure measurement

The CG127 2011 NICE Hypertension guidelines includes generic guidance on the measurement of blood pressure, including the key recommendation that 24 hour ambulatory blood pressure measurement be used before anti-hypertensive treatment is initiated. However out of the entire 317 page document, there is only one 6 page section on measuring blood pressure.

This section focuses on the different ways and methods of measuring blood pressure and the different types of devices available. The question is could the selection of the latest devices       streamline the blood pressure measurement process and save time, as well as clinical resources?

Is there a case for developing a suggested PMS algorithm for blood pressure measurement and what form should this take?

Step One Use a Waiting Room BP Monitor

Monitors like the TM-2655P waiting room monitor for patient self-measurement have been available for some time. They are convenient, easy to use and cost effective. They can be effective opportunistic screening devices and may identify patients with undiagnosed Hypertension.

Many also provide additional clinical information such as whether an Irregular Heartbeat is present. Many GP practices utilize them as part of a drop in service as they allow patients to monitor their own BP without making an appointment. This frees up clinicians for other duties. As with any BP monitor, it is important to check the monitor is listed on the BHS web site (www.bhsoc.org). Monitors that measure from the upper arm are recommended.

Step 2 Confirmation with a manual measurement

If it is felt that a reading from a waiting room blood pressure monitor needs clarification, an additional measurement should be taken. The BHS provide “best practice” guidance on the correct way to record blood pressure using an automatic or manual device. Most clinicians will rely on a clinically validated automatic monitor.

Most of these low cost devices like the UA-1010 feature an irregular heartbeat indicator and some have a “Tricheck” feature, which will automatically repeat a measurement three times, in accordance with BHS recommendations.

For patients identified with an irregular heartbeat, non-Mercury manual devices like the UM-101 are available.

Step 3 Use ABPM – The Gold Standard

The cost of ambulatory blood pressure monitors has fallen considerably over the last few years.  Like spirometers and ECG machines, the latest models such as the Meditech ABPM-05 feature software that provides automatic analysis of the results for consistent, time saving reporting to NICE Guidelines.

No More New Mercury Sphygmomanometers

The confusion that has surrounded the use of Mercury in medical devices has been rumbling on for several years. It’s use was restricted in thermometers some years ago but 2014 now finally sees the banning of it in new Mercury sphygmomanometers for environmental reasons.

The sale of Mercury Sphygmomanometers is now banned under EU directive no 847/2012 which also bans the use of Mercury strain gauges.

Alternatives to the Mercury sphygmomanometer and Mercury strain gauge are widely available, in the case of strain gauges they now use Indium Gallium.

The highly popular validated A&D UM-102A offers Auscultatory manual blood pressure measurement without Mercury in a compact design it even looks like a Mercury sphygmomanometer! Hybrid automatic and manual sphygmomanometers like the A&D Medical  UM-211 are also available.

Interestingly enough the directive does allow the use of Mercury as a reference standard for the validation of new blood pressure monitors and for research. So the Gold Standard still lives on since it’s invention over 130 years ago in 1881!