John_F Loc: Minneapolis, MN

I use both the Omron digital bpm HEM-711 and Omron Intellisence (some of the doctor offices use this one). Accuracy is important, of course, but a BP measurement is both the systolic and diastolic points and sensing them correctly is essential. That is what your doctor meant by calibrating. What percentage error invalidates a BP test, I wish I knew.

OldEarl Loc: Northeast Kansas

I have a tremor that impacts my readings. A nurse using a pump up meter can get an accurate reading. Automatic BP meters, whether home or in an institutional setting read high. I got a wrist meter once that gave me readings that do not exist.

Nelson.I Loc: Monument, Colorado, USA

Better than that, take this post AND your details to http://www.instructables.com/ where you will find a very appreciative audience.

louparker Loc: Scottsdale, AZ

Age is a definite factor -- BP "normally" increases as you age, so that while 120/80 may be "normal" for younger people, when get to be 65 or older, 140/90 may be "normal." Also, BP often fluctuates minute-by-minute. I have what's called "labile" hypertension, which means that my BP fluctuates significantly throughout a 24-hr. period. The best way to check that is to get your doctor to do a 24-hr. study where you wear a cuff and monitor constantly for 24 hrs. and it inflates every so often (anywhere from every 20 min. to every hour) and records the reading on a small device attached to the cuff. Then you return the device to your doctor and he/she downloads the readings to see what your average BP is throughout an entire day. I have had that done a couple of times, which led to a diagnosis of "labile" hypertension with the result that my doctor is not overly concerned about the high readings. He also advised me to check my BP every night before going to bed and only if the systolic is over 140, take 5 mg. lisinopril, or if it's over 150, take 10mg lisinopril. Following that advice, I only have had to take any lisinopril 2-3 times a month. And, when I check my BP at night, I follow the procedure recommended by the Mayo Clinic, which is to take 3 readings, one minute apart and average them, making sure I breathe deeply and relax as much as possible in between -- the 1st reading is usually the highest with each subsequent reading lower. Most doctors and nurses simply do not know how to check your BP correctly, particularly because they usually check it after they have asked or while they continue talking with you while they are taking your BP -- that's a no-no, as just normal talking will elevate your BP in addition to the "white-coat" syndrome from just being in a doctor's office and your anxiety about having your BP checked -- I know because I'm a prime example of one who has the "white-coat" syndrome. I often check my BP at home about an hour or so before a doctor's appointment and it may be "normal," but when I get to the doctor's office, it's always higher. Because my PCP knows my situation, he has me sit quietly in the exam room by myself for at least 5 min. before taking my BP, but his nurses often don't get the message. Even when I had the 24-hr. monitoring done the last time, I knew that the cuff was going to inflate every hour on the hour, so I had a certain amount of anxiety about that just before the reading was taken, which raised my BP, so if you do the 24-hr. monitoring, you should use a device that randomly takes a reading, like the 1st time I had it done.

JohnFrim Loc: Somewhere in the Great White North.

Thanks, I'll take that as an endorsement. And I am working on a description of my setup. I am wrestling with "make something along these lines" vs "make it exactly like this". Certain bits are critical and others are not, but I will give it a try.

berchman Loc: South Central PA

Forty-five years ago I went to a medical supply store and bought a professional Baum mercury blood pressure machine and a stethoscope, read instructions on how to use it, and I follow the recommended protocol of sitting quietly for five minutes, feet flat on the ground, arm supported at heart level, and average three readings. I have more confidence in a mercury sphygmomanometer than I do in an automatic Omron. Perhaps that lack of confidence in the Omron is unwarranted.

Delderby Loc: Derby UK

It is not always possible to reduce BP by treating a cause.
However it should be possible to reduce BP by using prescribed medication(s) regardless of cause. This will have a beneficial effect by reducing the strain on our systems, consequently reducing the risk of stroke etc.

JohnFrim Loc: Somewhere in the Great White North.

As I have alluded to a few times, BP measurement involves 2 major aspects: accuracy of the pressure reading; and determination of the pressure at the time of systole and diastole. Based on my calibration check I have complete faith in the accuracy of my Omron pressure transducer, and I believe it is as good as a mercury sphygmomanometer.

The determination of systolic and diastolic pressures is entirely dependant on detecting the appropriate sounds (stethoscope) or oscillations (Omron) in the blood flow. The parameters of the algorithms in automatic devices have been tweaked to give the same readings on average as those obtained by multiple human-derived measurements under standard conditions, and I also trust them if the automated devices are used correctly.

Given the variability in BP over time (even between beats), between left and right arm, and the inevitable variability between manual observers/testers even on multiple measurements I am reluctant to interpret any single manual reading that differs from an automated reading as confirming that there is a calibration error in the automatic device. I will certainly take my Omron to the office on my next visit and am looking forward to see what they conclude about my machine. If they suggest an error/offset in the pressure transducer I will let them know that the transducer is reading correctly and that the discrepancy can only be between the human BP taker and the Omron algorithm (again, I have faith that this was developed with a lot of effort).

JohnFrim Loc: Somewhere in the Great White North.

I don't deny the benefits of keeping blood pressure in check to prevent strain on other systems. But in my case the medication seems to be doing very little.

Trandolapril is an ACE inhibitor/vasodilator that is supposed to reduce peripheral vascular resistance, and if everything else remained the same then BP should come down. If indeed my peripheral vascular resistance is reduced by the drug but my BP remains slightly elevated as before, then clearly the heart is compensating for the lower resistance. By how much? By whatever it takes to satisfy the control element that seems to think I need higher blood pressure.

I would certainly like to know a lot more about the cardiovascular control system but it seems very complex, so much so that I am not yet convinced that science has figured it out to the finest detail. I know enough about electronic closed loop control systems with multiple feedback pathways to know that measurement of only one aspect of the system (BP) is NOT enough to determine why the system is manipulating ("overcorrecting" ) that one aspect in that way. I believe my elevated BP is the result of some cardiac response (stroke volume?) to an input signal, which itself is the sum of many input signals. The correct treatment lies in determining which of those input signals is calling for the increased circulation that does not seem to abate when relaxing the blood vessels.

To the docs out there... have I got this right, or am I wrong?

Jackdoor Loc: Huddersfield, Yorkshire.

You're mostly right! Sometimes there's a specific cause which can be treated- narrowed renal arteries is a good example, as is phaeocromocytoma.
For most of us, there's no single specific cause for raised blood pressure, and any attempt to reduce the pressure causes the homoeostatic mechanisms to try to counteract this change. Many current drugs- ACEIs and ARBs- actually work on these mechanisms.

MTG44 Loc: Corryton, Tennessee

I am getting a headache reading all this. I just go to to doctors and grocery stores to average mine.

JohnFrim Loc: Somewhere in the Great White North.

Take some Aspirin... good for the headache and maybe even the heart. :)

davidk2020 Loc: San Diego

Bad idea using the free stations in the drug store or grocery. How often do you think anyone cleans them? (Answer: Never.) So how much fecal bacteria do you suppose is on that red button? :shock: I wouldn't touch one of those with a ten-foot pole.

The Omron units are surprisingly good. I have an old wrist cuff that still gives good readings, but got a newer Omron BP791IT because it stores two readings per day (for one or two people) and if you plug it into the computer it graphs all your readings. I guess my GAS extends to medical devices now.

Earworms Loc: Sacramento, California

A Sphygmomanometer.

jerryc41 Loc: Catskill Mts of NY

Thanks for the suggestion, but trying to get something like this to work would cause a steep rise in my blood pressure. :cry: