Home blood pressure machines (vs, nurse, wrist, ears)

[victimofGM]

Originally Posted by allthatglitters

After a medical emergency I was advised by a cardiologist to monitor my BP regularly at home. I asked her how accurate those machines are and she said VERY. I ordered the best arm cuff Amazon offered and the results match those of a clinic visit.

Calibration and how often the unit needs to be replaced is beyond my scope of knowledge.

I’ve learned it’s also a matter of properly putting the cuff on the arm. If wrapped too tight then you’ll get a false high pressure reading. The area of the cuff where the tube comes out must also be placed in line with the inner center of the elbow. How you sit as well as not having taking medications or eating or drinking prior to testing are also important.

[allthatglitters]

Originally Posted by victimofGM

I’ve learned it’s also a matter of properly putting the cuff on the arm. If wrapped too tight then you’ll get a false high pressure reading. The area of the cuff where the tube comes out must also be placed in line with the inner center of the elbow. How you sit as well as not having taking medications or eating or drinking prior to testing are also important.

Yes.

Also, make sure your bladder is empty, as a full one can temporarily raise blood pressure.

[glenninindy]

Also, try to make sure to get one with an arm cuff that isn't too thin or it will wear out, wrinkle, fold, and slide around the bar that holds it.

[Travelassie]

Originally Posted by allthatglitters

After a medical emergency I was advised by a cardiologist to monitor my BP regularly at home. I asked her how accurate those machines are and she said VERY. I ordered the best arm cuff Amazon offered and the results match those of a clinic visit.

Calibration and how often the unit needs to be replaced is beyond my scope of knowledge.

I'd think taking your unit to your doc's office periodically to compare readings with those of the office unit readings would suffice in lieu of going through the process of calibration of your machine.

[guidoLaMoto]

Short answer to the OP's original question-- old, unused BP apparatus is probably still good uless it's been badly abused. Just check it by comparing a reading from it vs another, trusted unit. Many "old fashioned" aneroid cuffs/dials have a "zero" which the needle shoud point to when the cuff is deflated. If it's not on the zsro, it needs re-calibation.

I've always found that the new digital meters are more sensitive than human ears and often give spuriously high readings.--especiallhy true in older pts with "lead pipe" arteries. (Sound travels louder & faster in denser tisuue)

A couple points about taking BPs & the "pros" who do it regularly...I've found most of them don;t actually know what they're doing and just go thru the motions they were taught....Anyone who thinks a BP can be reported with an accuracy of more than ~ +/- 5mmHg certainly doesn't know what they're doing, unless they actually have a needle in the artery and are measiuring how high the blood squirts--->. BP readings are based on flow/no flow of the blood after one heart beat and before the next. With 5-10/10ths of a second between beats, that needle on the dial can easily fall 5-10 units between beats. (Let the pressure out of the cuff slowly for best accuracy)

When we talk about BP, we are implying "resting" BP-- no recent physical activity, no anxiety, normal posture, etc. Just talking while your BP is being taken will make it go up.

The cuff needs to be level with the heart. Above the heart, the reading will be artificially low; below the heart, artifically high. The cuffs designed for the wrist are adequate unless there is severe hardening of the arrtieries or variable heart rhythms.... Variable heart rhythms (like a fib) will make any reading less accurate because, technically speaking, each heart beat has its own pressure. With a fib, for example, some beats are not even felt all the way down at the wrist.

Pts with lead pipe arteries often have BP readings with very high systolic numbers and very low diastolic. Check that by doing a BP by palpation--> instead of listening with a stethoscope, just feel for the wrist pulse. When the cuff is pumped up higher than the BP, there is no pulse. As you let the air out of the cuff, the pulse will be felt when the systolic pressure is reached on the dial....There's often a difference of 10-40 mmHg in the ausculatory vs palpatory reading. The palpatory reading is the correct one.

In regards accuracy, decisions to alter treatment won't be affected by changes of BP of less than about 10 or even 20mmHg, so, how accurate do you need to be?

[Teacher Terry]

The arm BP machines are extremely accurate. The wrist ones are not. I occasionally take mine to the doctor to make sure it’s still accurate. Taking it correctly is key.

[BobTex]

OK, gonna give my tidbit pearls from experience of 30 years working critical care, trauma critical care, and neuro critical care with neuro being the biggee here since B/P control was so essential with aneurisms, strokes, and intercranial hemorrhages. Disclaimer is I've been retired since 2020 although I do some continuing ed for my licensure.

A substantial number of our patients required arterial pressure (B/P) monitoring. This is done by placing a soft catheter into an artery and is a continuous reading that recalculates pressures every 2 seconds. Correct setup is imperative but easy. As a charge nurse I checked setups on all pressure lines in the unit several times daily with a laser level and visual inspections. This setup is the gold standard for B/P monitoring in critical care.

Most of our patients ... 90-95% , were also monitored with standard auto cuffs connected to the overhead vital sign monitor which would generally cycle once an hour so checking the values against each other was easy if you were there at the time it was taken by pneumatic cuff. Also we could check trends graphically. Most of the time (85% is a guess here) there was coordination and a measurement off by 15 mm was acceptable. Same with the roll around auto machines which we used if we suspected and error in the overhead maching. We were also , as caregiver RN's, expected to do at least 2 manual checks per shift .

Caveats and other pearls:

- I've seem significant differences between appendages (L arm vs R arm). This is explainable by poor circulation in one arm vs the other.
- We discouraged wrist measurements, our secondary sites were the calf targeting the popliteal artery.
- Many docs wanted manual measurements done every other hour and some wanted only manual measurements vs the auto-pneumatic. Different strokes for different docs.
- Stimulation can make significant changes in pressure. Thus the "white coat syndrome" we all have heard or read about but also pain is significant. Temporary stimulus in a healthy circulatory system just results in a very temporary spike in pressures.
- Also, taking a B/P is like taking a picture (I was gonna say a Polaroid) but it is a snapshot in time. Sitting in the ICU watching monitors and fluctuations of vital signs taught me how fluid our bodies are and how they are in constant change. So if you get a B/P you are concerned about sit down, calm yourself, apply your cuff using good technique and retake it. Trends are more important than single readings.
- One last thing on the docs and the hospital routines. On mobile patients taking pressure readings in different positions (lying, sitting, and standing) was required and each would change in that relationship with posture.


I said all that baloney above (I guess) just to say a manual B/P is best and we should get a manual cuff and get a family or nurse friend to do a manual check against our auto machines. Get an idea how your machine reads vs several other readings/methods/practitioners.

[Hemlock140]

Originally Posted by elnina

Most home BP monitoring machines aren't accurate at all. Even new. They weren't ever validated for accuracy.
Especially those upper arm and wrist cuffs. Simply because manufacturers are NOT required to have their products validated.
You might want to check if your machine is validated on this website:
https://www.validatebp.org/
The monitor should be approved by the FDA and validated by the VDL or STRIDE BP. Validated BP monitors have ISO validation protocol #

I agree with this. We currently have 3 of them. If I take my BP 3 times in a row, each with a different one, they will all be different. If I take it 3 times in a row, all on the same device, they will all 3 be different. It's impossible to tell whether it's the device or it actually changes that quickly. The cheap wrist ones seem to be the worst, the larger one with an arm cuff better. The old Sphygmomanometer type used by some doctors seem to be the best.

[wit-nit]

Originally Posted by Hemlock140

I agree with this. We currently have 3 of them. If I take my BP 3 times in a row, each with a different one, they will all be different. If I take it 3 times in a row, all on the same device, they will all 3 be different. It's impossible to tell whether it's the device or it actually changes that quickly. The cheap wrist ones seem to be the worst, the larger one with an arm cuff better. The old Sphygmomanometer type used by some doctors seem to be the best.

Your BP is constantly changing. Your every movement, attitude makes a difference and it's natural for your BP to react to these changes.
In my doctor(s) office several times I disagreed with their findings and had them do it over again immediately and each time we got a different reading. Doc(s) have said yes it's true to have short time BP readings to read diffferently.

[sholomar]

I find almost all of those machine operated blood pressure checkers give higher readers than a nurse using a cuff, doing it manually. I've had a lot of blood pressure checks from doctor visits over the years and this is the case virtually all of the time. I've asked nurses to take manual readings after throwing me on the electronic unit. Same result. Every time. Their manual reading is lower. Which is more accurate? Who knows.