A few questions about taking blood pressure....

[Knicks]

I was reading Bates' Pocket Guide to Physical Examination, 5th edition and I have a couple of questions:

1- Do you guys use the diaphragm or the bell of the stethoscope? I always use(d) the diaphragm but this book recommends using the bell.

2- I was always under the impression that once you begin to deflate the cuff, you should NOT re-inflate it (while deflating). Either I didn't understand what the book was saying about this or the book is a little ambiguous, but the book mentioned something about re-inflating. Once you start deflating, you DON'T all of a sudden start re-inflating again, right?

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[schussboarder]

I was reading Bates' Pocket Guide to Physical Examination, 5th edition and I have a couple of questions:

1- Do you guys use the diaphragm or the bell of the stethoscope? I always use(d) the diaphragm but this book recommends using the bell.

2- I was always under the impression that once you begin to deflate the cuff, you should NOT re-inflate it (while deflating). Either I didn't understand what the book was saying about this or the book is a little ambiguous, but the book mentioned something about re-inflating. Once you start deflating, you DON'T all of a sudden start re-inflating again, right?

1. the way I was taught and how a majority of people at my school do it is using the diaphragm. I have only witnessed one dr. using the bell and he said that there is no significant difference in which side you use, its just personal preference.

2. Are you sure the book didn't mean after initially taking a palpatory pressure to re-inflate to take an ausculatory pressure. Other than that I can't imagine any reason to re-inflate the cuff while taking a blood pressure.

 

[umean2tellme]

If you initially inflated to, for example, 160 and you started hearing sounds immediately, then you're supposed to deflate completely then reinflate higher so you can get the real systolic pressure.

I've always used the diaphragm. If you push down on the bell hard enough it acts like a diaphragm anyway...

 

[Siggy]

1- Do you guys use the diaphragm or the bell of the stethoscope? I always use(d) the diaphragm but this book recommends using the bell.

I've always used the diaphragm, but have messed around a bit with the bell. The thing with the bell is that it's better at picking up low pitch sounds, like Korotkoff sounds.

2- I was always under the impression that once you begin to deflate the cuff, you should NOT re-inflate it (while deflating). Either I didn't understand what the book was saying about this or the book is a little ambiguous, but the book mentioned something about re-inflating. Once you start deflating, you DON'T all of a sudden start re-inflating again, right?

I think the key for this is that you aren't supposed to sit with a cuff inflated for ever on a patient's arm. If I'm moving too fast when Korotkoff 1 or 5 starts, I'll go high enough to get those sounds. However if I start releasing pressure and don't hear anything, then I'll deflate and start over.

 

[turkeyjerky]

we were taught to use the bell

 

[alehar]

We were taught to use the diaphragm. And yeah, any reinflation is either because you palpated the systolic and you're going for the actual bp now, or because you didn't go high enough after palpating the systolic (20-30 higher is a good estimate)

 

[ChiDO]

Most steths have the diaphragm and bell built into the same side. My steth (littman cardio 3) has a peds and adult side, and each side functions as a bell (light tough) or diaphragm (deep touch). The bell is used for BP.

When measuring BP, you are supposed to take the radial pulse, inflate the cuff till you no longer feel the pulse (~100), deflate, then reinflate to 20-30 over where the radial pulse disappeared. This is to prevent an auscultory (sp?) gap from happening, where the systolic is actually 160-180 and you thought it was 120.

 

[Knicks]

........deflate, then reinflate to 20-30 over where the radial pulse disappeared........

This is where I was confused. For some reason, I thought that after we inflate a cuff and then want to re-inflate again to measure the pressure, we have to wait about 5 mins before doing so.

 

[cpants]

My advice to you is don't overthink it. The BP isn't neurosurgery. Bell or diaphragm side is irrelevant. Either will work. Inflate to 170ish and then release the valve so the cuff slowly deflates, around 2-3mm Hg/sec. If you hear korotkoff sounds right away, you underinflated and you'll need to try again inflating higher. Try around 200. While in general you shouldn't reinflate while you're deflating, it really doesn't matter. If you are deflating too fast and miss one of the points (a common beginner mistake), just give a couple squeezes without touching the valve and listen again. You really don't need to measure a palp systolic first. It may be what Bates says, but in practice no one does this.

It's pretty easy to master. Just do it 20-30 times and you'll be a pro. You can even practice on yourself.

 

[Knicks]

My advice to you is don't overthink it. The BP isn't neurosurgery. Bell or diaphragm side is irrelevant. Either will work. Inflate to 170ish and then release the valve so the cuff slowly deflates, around 2-3mm Hg/sec. If you hear korotkoff sounds right away, you underinflated and you'll need to try again inflating higher. Try around 200. While in general you shouldn't reinflate while you're deflating, it really doesn't matter. If you are deflating too fast and miss one of the points (a common beginner mistake), just give a couple squeezes without touching the valve and listen again. You really don't need to measure a palp systolic first. It may be what Bates says, but in practice no one does this.

It's pretty easy to master. Just do it 20-30 times and you'll be a pro. You can even practice on yourself.

Oh I definitely agree, as I've taken countless BP's during rotations. I usually just went upto 180.

But I was just re-reading this Bates book and the part about BP stood out to me, and so I made this thread.

Thank you for the input, and everyone else too.

 

[Captain Fantastic]

A 2005 article in the Journal of Hypertension concluded either side was fine and gave similar results. Earlier studies (1980's) seemed to show that the bell, being more sensitive to lower frequencies, picked up the sounds a bit earlier and held on to them a little longer than the diaphragm. The size (and tightness of the cuff around the arm before inflation) can play into it, too, since the manometer is measuring the pressure in the cuff and not the pressure in the vessel. Anyway, interrater reliability isn't great with BPs, in my experience.

I agree with cpants, don't over think it: Inflate, slowly deflate, listen, done.

 

[bydotte]

i don't think it matters

 

[engineeredout]

Does anyone in real life actually check for auscultatory gap with every BP they take on a patient?

 

[NTF]

Does anyone in real life actually check for auscultatory gap with every BP they take on a patient?

Definitely not. The only time I ever did it is with frail and elderly patients (or patients with sensitive skin or arms) and only if they couldn't communicate effectively. If they could I'd just ask them what their BP usually was and go 20-30 above that.

 

[njbmd]

Does anyone in real life actually check for auscultatory gap with every BP they take on a patient?

I do and I have instructed my staff to report this information. Since my patients are vascular surgery patients, this info is useful to me at time.

 

[Knicks]

Pretty tired at the moment, but what precisely causes that auscultatory gap again?

 

[deuce924]

Pretty tired at the moment, but what precisely causes that auscultatory gap again?

It is the gap when [FONT=verdana, arial, serif][SIZE=-1]Korotkoff [/SIZE].sounds are not heard when taking a blood pressure. For example, you pump the cuff up to 180 and start releasing it and hear the sounds at 120. As you continue to release the cuff, you may not hear any sounds for a period of time and then hear them again at say 100.

The period of time/pressure in which you didn't hear anything is an [FONT=verdana, arial, serif][SIZE=-1]auscultatory gap. [/SIZE].From what I've read, the presence of this gap may be caused by or indicative of hypertension.

 

[engineeredout]

I do and I have instructed my staff to report this information. Since my patients are vascular surgery patients, this info is useful to me at time.

Yes then it would seem to make sense for you and your patients. I was just curious as we were told in the H&P class that it should always be checked for, but I don't remember anyone ever checking on me (or else they were so good that I didn't even notice).

 

[J ROD]

I just looked at previous pressures and inflated above those and got my readings. I found the other step too long in normal situations....