Measuring Blood Pressure

[axel_knutt]

The best ones in the Which report were the Kinetik BMP1C, and IBP HL868ZA. Don't jump to conclusions about those particular manufacturers though, the Kinetik BPM3 and IBP Hl168ZA were among the worst.

[Mick F]

Have you checked the accuracy of your testing kit against apparatus which has been calibrated?

When I started with heart disease, in a total tizzy, I went through a period of doubting everything and bought my own machine. I got my specialist cardiac nurse to check with her calibrated machine and I used my own immediately afterwards. Mine gave a significantly lower result. In other words, just because you have some official-looking numbers in an LCD display, it does not mean they are inevitably right.

Good point.

There's a big DIY BP machine in the local health centre that you sit next to and stick your whole arm into. I'll pop in maybe later or tomorrow.
Trouble is, it's half a mile away then up a steep hill ............ and I'll walk. This means I'm not relaxed and no doubt the result will be like suffering from White Coat Syndrome. I'll have to have a sit down and read a mag or something first.

Just thinking ................ I could take my Lidl unit and strap it on one arm, and stick my other arm into the health centre's device. Two readings at the same time!

[Tangled Metal]

When I got that one high reading, when my normal state was low BP, I got told to come back in a number of weeks and ended up having IIRC 4 measurements being taken over a spell of weeks. It was only that one reading that was high.

The issue I have with BP and the NHS is there is no advice for low BP which latest research seems to be bringing evidence that low BP is as harmful or more so than high BP based on the number of conditions it is being linked to. In my case I went through a number of years of blacking out almost every time I got a bad cold as my BP dropped like a stone. The GP told me what the medical profession calls it and told me to be careful going up stairs, ladders and out of a chair. Then sent me on my way. Made me a bit annoyed because one of the issues i had was getting up to go to bed. up the stairs and anything could trigger the passing out. A major trigger was having a pee believe it or not. All this monitoring and advice for high BP and nothing other than don;t do something you have to do just to live.

Sorry, off topic rant over.

[Tangled Metal]

Those GP machines are very questionable. i took a reading then another one 10 minutes later and the results were totally different. So far apart in fact that one was low BP the other was high. Do not rely on those as I suspect their use is not as straightforward as they seem and they are not reliable IMHO. If you want to check then book an appointment with your practice nurse for a check up. He/She will use a reliable and probably calibrated BP monitor which you can then check against yours. I think you are able to just book in with them, might have to give a cock and bull story about being worried about BP for some reason.

[thirdcrank]

Most machines are only as reliable as the operator. I've had my BP checked at hospital outpatient appointments in all manner of careless ways which I knew from reading it up weren't best practice. That, combined with checking a patient's weight without paying regard to whether they are heavily dressed or virtually naked must be enough to affect the results.

[Tangled Metal]

Well once when I had a check up they needed my weight and height but being lazy they just asked me for it. Very good practice I think!!

Another time they tried measuring my height but the measuring device mounted to the wall was 2" or so too short for my height.

Another visit they took my BP and HR with one device which wasn't working for BP so switched to another which also failed. Both were electronic ones that do it all automatically. Then the young nurse had to get one of her older colleagues in to use the old school BP decide that they pump up while holding a stethoscope to the forearm to listen for the beat to stop. The younger nurse did not know how to do it hence the frustrated attempts to get both automatic devices working.

You have to laugh sometimes and the way things are done in the NHS. They may have issues but at least they get there in the end.

[axel_knutt]

This is the one that was monitoring me at the weekend. Interesting that there's no mention of BP measurement accuracy.

Most machines are only as reliable as the operator. I've had my BP checked at hospital outpatient appointments in all manner of careless ways which I knew from reading it up weren't best practice.

The monitor above aborts the measurement and starts again if your arm is not relaxed enough.

[Mick F]

There's a big DIY BP machine in the local health centre that you sit next to and stick your whole arm into. I'll pop in maybe later or tomorrow.

I had a go at it this afternoon.

I had to do the shopping today .............. ho hum, the delights of retirement whilst SWMBO still works ............... and I called in on my way back. Luckily, I could park the car nearby.

I did it twice:
150 over 87, then after a pause of two marching paces, 140 over 86.

Question:
The machine gives you a printout.
SYS 140 mm Hg
MAP 105 mm Hg
DIA 86 mm HG
PUL 79 bpm

I can understand SYS, DIA and PUL, but what does MAP mean?

Yes, I know I should have asked the receptionist.

[axel_knutt]

I can't fathom blood pressure, I'm left thinking that the variation between one normal individual and another is nearly as large as the variation between clinically low and clinically high.

[531colin]

I will hazard mean arterial pressure....and I know it isn't the arithmetic mean of those 2 numbers......passage of time is making all this terribly hazy, .....if you look at the pressure/time trace, the upward spike is steep, ie short duration, there is a "hiccup" as the left ventricular pressure decays and the aortic valve closes, then the slope is less steep, meaning more time at the lower pressure .....so is the "mean" to do with area under the curve, or something, all you mathematical types?
.....Blimey, I didn't know i remembered all that lot......I think I'm somewhat opposite to Mick....I can do the biology, the maths leaves me behind!

And Axel is right, there is a huge variation in pressure between individuals, or the same individual on different occasions, and different arms of the same individual.
but there is also a huge amount of clinical experience going back decades (centuries?) which gives quite a lot of weight to the idea that certain pathologies are inextricably linked to high blood pressure......not every hypertensive patient will get all the problems in any one year, but the dice are very heavily loaded.
....and hypertension is progressive unless it is controlled.....if your pressure gets high enough, you will feel B. awful a lot of the time.

[axel_knutt]

Three years ago when I had a paramedic out, my heart arrhythmia meant I was unable to stand without fainting. "No wonder you can't stand you're losing most of your blood pressure". My BP was 104, well within the "normal" range. A few months later I was in for a bowel operation, and at one point I was unable to sit up without fainting. My BP was 103 and the nurse said "no, that's fine, it's normal". I've been in on numerous occasions when it's been ~105, and each time it's been regarded as normal.

Wind the clock on to last weekend, I was back in A&E, and my BP was around 104 again but they decided it's so abnormal that they put me on 3L of IV fluid!!
I reckon I'd be unconscious if I was at 90, the bottom of the 'normal' range.

[531colin]

Three years ago when I had a paramedic out, my heart arrhythmia meant I was unable to stand without fainting. "No wonder you can't stand you're losing most of your blood pressure". My BP was 104, well within the "normal" range. A few months later I was in for a bowel operation, and at one point I was unable to sit up without fainting. My BP was 103 and the nurse said "no, that's fine, it's normal". I've been in on numerous occasions when it's been ~105, and each time it's been regarded as normal.

Wind the clock on to last weekend, I was back in A&E, and my BP was around 104 again but they decided it's so abnormal that they put me on 3L of IV fluid!!
I reckon I'd be unconscious if I was at 90, the bottom of the 'normal' range.

The bit that i have coloured shows that you have more understanding of your condition (AF, right?) than some of the people you will meet in the Health Service.
There are a few people who " normally" have a systolic BP in the low hundreds and can function at that because its normal for them. It would lay me straight out, I'm borderline hypertensive on medication.
Sorry if I'm doing that grandmother and eggs thing......
In the "normal" situation the heart beats in a very systematic way, its wired up like that. The "input" of blood at low pressure from the circulation comes into the atria, the atria contract (first heart sound) and fill the ventricles, the big muscular ventricles contract and force blood at high pressure into the circulation (second, louder, heart sound, pulse pressure wave felt).
In AF, the wiring is shot, and the atria are going 19 to the dozen, without enough input blood to fill them. The ventricles can't keep up, and fire randomly when they can. If they happen to be full, you get a good squirt of blood and a good pressure. If they are half-full, you get a low pressure but much more importantly not enough volume of blood going to the brain to keep the lights on.
A patient in AF will have a different "pressure" for every heartbeat, its almost pointless measuring it. Systolic will vary with how a good a "fill" the ventricle had, and how long since the last beat, and how full the last beat was. Diastolic will continue to fall until you get a couple of good full beats reasonably close together.

[Tangled Metal]

colin you seem well up on the hypertension but (and probably a long shot since you have hyper) do you know anything about Hypotension? I have applied the opposite to hyper to get what I assume is the term for low blood pressure? I only ask because I had it (might still but I'm no longer good at GP due to white coat I think) and it was in the family as well. In fact the trend is low BP then due to other conditions when a lot older the family member goes onto drugs which sends them into high BP. Also it has happened as the family member got old, however up until then they are at risk of blacking out due to low BP and especially if under stress due to infection, colds, flu etc.

Also I am concerned that low BP is a poorly understood condition that is slowly being studied with the result that some experts in it are actually worried it is as serious as high BP and needs a lot of research into it. IIRC Dementia is one condition linked but a lot of other game ending conditions too. This is my reason why I think I need a BP monitor (especially now I am in my 40s.

[531colin]

Hypotension is the word.
I had a quick Google, and there is not much about except "orthostatic hypotension".....the familiar standing up then falling over.
There is a British Society for hypertension, with an open-access website which will tell you all you need to know about treatment of hypertension, NICE guidelines, etc.....but hypotension seems to be a bit of a cinderella....I got a few hits with "hypotension uk" but nothing that really grabbed my attention as authoritative/complete/helpful/etc.

[Tangled Metal]

Exactly what I've found. I remember a programme on tv that went into it. Think it had interviews with researchers in the field of hypotension. It said more and more research from around the world was gaining momentum in acceptance that there is evidence of links between many serious conditions and hypotension. Sure it was dementia and something like strokes.