EBME Forums Forums Management Training Manual Blood Pressure Equipment

Having read this thread with interest I am going to throw my hat into the ring and offer my thoughts on this very important subject.

There are two well known and well documented methods of taking a non-invasive blood pressure measurement (NIBP).

1 – With an automatic digital blood pressure monitor (albeit some of which are clinically validated and some are not).

2 – With a manual sphygmomanometer (as above, some are clinically validated and some are not).

Gadget queen, your original question asked for information on the Greenlight v the UM-101 coupled with whether or not you should contemplate moving away from automatic devices to manual devices. With this in mind I am not going to elaborate on digital devices in this post or my post will be some 500 words longer than it is now and probably bore most of you to sleep. What I will do is try to impart my thoughts and opinions, for what they are worth.

With regard to manual blood pressure measurements, I’m sure that most of you know that you require peace and quiet, skill, time and patience. The person attempting to take a manual blood pressure measurement should have undergone training to recognise what is known as the Korotkoff sounds. The first sound being the onset of the systolic blood pressure and the cessation of the sounds is the diastolic blood pressure.

An accurate manual measurement also requires a stethoscope suitable for listening to the Korotkoff sounds, a suitably sized cuff and a manual sphygmomanometer that is accurate across the entire pressure range that the device is capable of measuring (typically 0 – 280mmHg).

Manual devices fall into 3 categories;

Mercury – which is what we are trying to avoid.

Aneroid – which are notorious for being unreliable and/or requiring frequent and regular calibration across the entire pressure range.

Electronic – These are being used more and more frequently and as far as I am aware there are only three independently clinically validated devices and one that is pending a validation;

The Greenlight has already been discussed and looks similar to an aneroid device save for the fact that it uses 2mm light segments as opposed to a needle to indicate the mmHg pressure.

The Omron 907 is a dual device capable of measuring blood pressure automatically or manually (given the cost restraints that most Trusts are working under this device is prohibitively expensive when compared to other manual devices).

Whilst the MANDAUS sphygmomanometer uses a falling display of numbers, much like the display on a calculator.

The device that is pending a validation is the device that was referred to in gadget queens original post; the UM-101 Mercury-Free Sphygmomanometer – this device looks like a mercury column and it is used in exactly the same way. The difference being is that it uses 2mm LCD segments on a column as opposed to a mercury filled column.

Given that these four devices are electronic they are still MANUAL devices and for all intents and purposes a clinical validation is, in my opinion, pretty much useless.

I know that this is a bold statement but consider the facts.

A manual device, be it mercury, aneroid or electronic, can be tested with a simple static pressure test across the entire range to prove that it is accurately reporting a known pressure value, or not as the case maybe. Assuming that the manual device is reporting the pressure values accurately the weak link in using this method is the human link.

If the person taking a manual blood pressure measurement is not proficient in listening to the Korotkoff sounds then the chances of obtaining an accurate measurement is very, very low indeed.

In essence I believe that anyone that has to take blood pressure measurements should undergo a period of training that revolves around using a manual method before they can use an automatic device; this at least means that they should be able to use an alternative method as and when the automatic device fails.

Automatic digital blood pressure monitors don’t work on all of the people all of the time and a Report of the Independent Advisory Group on Blood Pressure Monitoring in Clinical Practice1 stated, as per MR R J Lings earlier posting, that there are certain clinical conditions where Oscillometric devices (automatic digital blood pressure monitors) are inappropriate and as such a manual method should be used. In addition to this various bodies such as the British Hypertension Society recognise that the ability to record a blood pressure measurement manually is a key clinical skill that should not be lost.

1 Committee on Blood Pressure Monitoring in Clinical Practice, Medical Device Alert MDA/2005/069

The conditions referred to include pre-eclampsia, certain vascular diseases and known arrhythmias (whilst some modern automatic devices can cope with arrhythmias, most can not); personally I would take this a stage further - I wouldn’t recommend or endorse the use of automatic digital blood pressure monitors on children or during any stage of pregnancy.

Gadget queen, to answer your question; if you wish to standardise on a manual device within your Trust I would happily recommend any of the four electronic manual devices that are currently available.

All four of these devices offer their respective advantages and disadvantages and this is where you need to decide on what’s important to you and your trust.

The Greenlight has been around for sometime and is well liked and used in certain geographical areas, whereas the Omron 907 does not appear to have much of a following due to its high initial cost. The MANDAUS is also being used in a number of clinical areas but the uptake is low due to the fact that it uses a numerical display which is somewhat unfamiliar compared to a column or dial type device. And whilst the UM-101 has only been on the market for approximately 12/14 months, initial indications are that it has been well received and liked due to the familiarity that it offers – it looks like, feels like and works like a mercury column but without the mercury.

Before anyone makes a comment implying bias on my part; yes I work for a company that supplies some of these items and no I’m not here to promote them.

I simply want to provide sufficient information in order that you can make an informed decision and choice as to which device best meets your needs and requirements.

Regardless of whether you choose the Greenlight, the Omron, the MANDAUS or the UM-101 you will have chosen a good, solid and reliable MANUAL device; just remember that they all require a working knowledge of the Korotkoff sounds before they can be used correctly and accurately.

There is a lot of talk here about there not being an alternative to the Greenlight, but has anyone out there gone with the UM101 device? That is the alternative that we are considering going with, but it has a display for the pulse (which we would want staff to ignore in favour of a manual pulse).

Gadget Queen, did you move to using all manual devices and if so what equipment did you purchase and what is your experience of it?


Rojo, how has the greenlight been performing in your area, are the staff happy using this and would you recommend it?

Kit,
Along with the introduction of the Greenlight the clinical educators are (re)training the staff on how to take a manual BP. This seems to be going well.
The only complaint, so far, is that the Welch Allyn monitors that they used to use for the obs also had a thermomenter and pulse-oxmeter with them. So now they need to take the WA and Greenlight around. I can envisage that this practice will gradually become too much hassle unless some small portable pulse-oximeters are purchased. They already have the thermometers.
The Greenlights are so easy to use that there has been no problem with their adoption and I know of no technical problems with them.
Robert

Sorry to have brought back the topic for discussion again.

Pls pardon me for my ignorance. Is the replacement of mercury sphygmomanometer is statutory requirement in UK now. What is the reason behind such a move. What puzzles me is these manual BPs have been around for ages and were considered as "gold" standard for measuring BP.

On the same note, is the Greenlight comparable with the Mercury kit.

The reason, I'm sorry to say Roger, is that the UK has been seized by the "Health and Safety mafia". The Great British Public are no longer to be trusted to think for themselves, and simply have to be told what's good for them. It's a (sad) state of affairs often summed up by the phrase "Nanny Knows Best"!

You see, it seems that we were all in danger of becoming Mad as Hatters by continuing to use "risky equipment" like mercury sphygmomanometers! These days we have to waste money on "high-tech" solutions to every aspect of our lives. The tried and tested methods handed down to us just don't cut the mustard, apparently.

But alas, only the other day I was asked to source a few of these deadly instruments for a charity hospital in Africa ... and couldn't immediately lay my hands on any. Does anybody have a few boxes of junked sphyg's they can donate?