Is There EBP Behind Two-Step Blood Pressures?

mindofmidwifery, ADN · Sep 11, 2017

I've actually read that results are similar whether you do one step or two step BP. The reasoning behind it, from what my instructors have said, is so you're not over or under deflating the cuff. I'm sure if you underdeflate it, it'll be inaccurate and inefficient because you won't get an actual reading in the first place and you'll have to recheck it which takes more time and makes your patient question your competency.

Future-NurseRedHeart · Sep 11, 2017

For underinflating, I've always been told that if we hear a sound immediately upon releasing the cuff, we should close the valve pump it again while already inflated rather than completely deflating and starting over again

Castiela · Sep 12, 2017

We used the radial pulse, but we were taught to do it the two step way where I graduated

Here.I.Stand, BSN, RN · Sep 12, 2017

For underinflating, I've always been told that if we hear a sound immediately upon releasing the cuff, we should close the valve pump it again while already inflated rather than completely deflating and starting over again

That's exactly what I did back when I took manual BPs. (I work in an ICU, so BPs are either automatic/connected to the monitor or from art lines.) The two step method sounds like a real pain. I can't even palpate my OWN brachial pulse, let alone that of an obese person or someone with vascular disease.

CelticGoddess, BSN, RN · Sep 12, 2017

That's exactly what I did back when I took manual BPs. (I work in an ICU, so BPs are either automatic/connected to the monitor or from art lines.) The two step method sounds like a real pain. I can't even palpate my OWN brachial pulse, let alone that of an obese person or someone with vascular disease.

We were taught the two step method in nursing school and I think we all promptly forgot it when we started working in the real world. I still do manual BP's (home hospice) but none of the two step junk! Too much time, if you ask me

chare · Sep 12, 2017

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Can anyone explain this to me because to my classmates and I, this makes very little sense. Thank you!

Yes, I can. There is a very good reason for using what you refer to as the two stepâ€ method when obtaining a manual blood pressure; the auscultatory gap. The auscultatory gap is a period when the Korotkoff sounds are either difficult to auscultate, or absent completely. When obtaining a manual blood pressure, if you inflate the cuff to a set number, 200 mmHg in your example, it is possible that when you auscultate and hear nothing that you could be listening during this period. While the exact occurrence of this phenomenon is uncertain, estimates range from 5% to 30%, depending upon patient population and underlying condition. This failure to properly identify an accurate blood pressure can lead to the patient's hypertension being seriously undertreated.

My school has recently changed the way we take blood pressure from the normal, one step method so now we take a two step. If you're unfamiliar with two-step, I know my clinical instructors were, they had to learn it with us, this is accomplished by palpating the brachial artery and pumping the cuff until we no longer feel the pulse, deflate the cuff, then +30 to systolic so that you inflate 30mmHg above when you stopped feeling the pulse (If you felt the pulse end at 130mmHg then you inflate the cuff to 160mmHg), then you take the blood pressure a second time but now you are auscultating like you do normally in one-step but not inflating right to 200mmHg like you do with one-step, but to the number that you received from palpating, then boom after a lot of effort you have a reading!
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This is how I was taught to obtain a manual blood pressure in my basic EMT class in 1987, and again in nursing school in 1996. I'm not sure exactly when, it stopped being taught but it likely arise as a result of the increased used of automated blood pressure devices. It is my opinion that, in not teaching this method we are doing both the students, as well as their future patients a grave disservice.

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1. Whether or not you do 1-2 step, you get the same reading unless their blood pressure is over 200mmHg systolic
Yes, but is it the correct reading. Assume you obtain a blood pressure using your method, and obtain a reading of 196/156. Using your method, this may or may not be correct. If you began auscultating during the auscultatory gap, then the patients blood pressure could be significantly higher. This could lead to the patient's hypertension being misidentified and/or mistreated.
2. It is time consuming because it takes a while to find the brachial pulse and not lose it.
I find this concerning. Where exactly should you place your stethoscope when auscultating a manual blood pressure? If you can't accurately find the brachial pulse by palpation, how do you know that you have your stethoscope in the correct location?
3. It makes us look incompetent because rather than taking blood pressure once, we do it twice and at the beginning it takes quite some time, I believe this would cause the client to be less trusting of the nurse and question if they would want someone to care of them when they appear not to be capable of doing something as simple as taking vitals.
Quite some time? I don't see how this is going to add more than 60 seconds to obtaining a manual blood pressure. You might consider using this brief time to gather some history from the patient. I not certain that your concern that this would cause the patient to be less trusting of the nurse and question if they would want someone to care of them when they appear not to be capable of doing something as simple as taking vitalsâ€ is valid either. If they do question you on this, all you have to do is explain that there are many methods of obtaining a blood pressure, and this is the method that you were taught.
4. You're taking blood pressure twice, doesn't that put greater pressure on the arm than it would inflating to 200mHg once?
It has nothing to do with the pressure exerted on the artery; the only concern is in obtaining an accurate blood pressure reading
5. Everyone is having a hard time feeling the brachial pulse especially because it isn't always strong, but when the cuff is inflated to a certain point the brachial pulse stops, wouldn't the radial pulse stop because it is below the cuff too? The radial pulse is much easier to find and not lose.
Yes, the radial pulse is most likely an easier pulse to palpate, and using it would work as a substitution for the brachial artery. And if I am in a situation in which all I want/need is a palpated blood pressure, the radial artery is the site I most likely am going to use. Again, however, if you can't locate the brachial pulse, how do you know that you have placed your stethoscope properly positioned to auscultate.
6. My school says they keep up with the hospital and what they are doing so that we get "real world" experience, but in the real world, two-step blood pressures aren't done, they use an electronic cuff, which by the way, inflates to 200mmHg like we would when doing manual.
Again, I find this somewhat concerning. In the real worldâ€ blood pressures, as well as all other procedures, should be performed correctly, and in the manner that will provide the most accurate and beneficial results for the patiet
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The instructors originally said they have no idea why we were doing it in the first place, which is not really encouraging. After us asking quite often "why" we have to do it this way, they figured out the "why" and they said the EBP behind it is that we put less pressure on the arm and it is supposedly more accurateâ€¦
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I agree, and really find it concerning for two reasons. First, a simple internet search would have revealed more than adequate information regarding the auscultatory gap and how to overcome this problem. However, and what I find most concerning is that failing that, the best they could come up with was it put less pressure on the arm and it is supposedly more accurate.â€

Best wishes as you continue through your program.

marienm, RN, CCRN · Sep 12, 2017

I was taught this method in nursing school in 2011. Except it was a little easier, I think-- my memory of how we were taught is:

1) Put on the BP cuff.

2) Find the brachial pulse with your finger.

3) Start pumping. Note the level at which you can't feel the pulse any more.

4) Pump 30mmHg higher than where you can't feel the pulse.

5) Place your stethoscope over the brachial pulse.

6) Begin deflating slowly (like, 2mmHg/second, which no one ever does in any doctor's office I've been to!).

7) Note your first 'tap' sound as your systolic pressure; the final 'tap' is the diastolic.

The rationale that I was taught for this is that 1) you don't over inflate on someone whose pressure is only 98/50 to begin with, and 2) you won't be fooled by the auscultatory gap by not inflating far enough.

If you can't find the brachial pulse, I guess this is harder. When I listen to heart sounds during my assessment I always check bilateral radial pulses, but I don't often check the brachial if I can palpate the radial. I admit I work in an ICU so I don't usually have to take manual pressures, but I can usually find this pulse if I put a pillow under the arm to straighten it out. (I just did this the last shift I worked, in fact, to confirm a BP that the monitor unexpectedly told me was 72/54. I listened and got 70/52, so then we hung a fluid bolus and like magic the pt's urine turned from sunset-orange to normal yellow!) It's much harder if you let the patient stay "comfortably" nestled in all their pillows with their arm bent.

RNby2021 · Oct 11, 2017

This was the method I was thought when I took my EMR course (and every first aid class except OFA3 actually):

1) Put on the BP cuff.
2) Find the brachial pulse with your finger.
3) Start pumping. Note the level at which you can't feel the pulse any more.
4) Pump 30mmHg higher than where you can't feel the pulse.
5) Place your stethoscope over the brachial pulse.
6) Begin deflating slowly (like, 2mmHg/second, which no one ever does in any doctor's office I've been to!).
7) Note your first 'tap' sound as your systolic pressure; the final 'tap' is the diastolic.

I feel that automatically inflating the cuff to 200mmHg is too harsh on frail elderly and underdeveloped child's arms (hell, it's too much for me too). We are learning the 2 step method in RN school right now and I find it is redundant to the above mentioned "EMR" method which also ensures you won't be fooled by the ausc gap. This "EMR" method is the method I have seen most often.

So why the switch to the 2-step method over the "EMR" method? There must be some benefit.