# Measuring blood pressure



## EMSSam (Apr 17, 2012)

When measuring a BP via auscultation of the brachial, I look at the gauge and see the needle start to flicker before I physically hear the Korotkoff sounds. 
E.g. I might see the needle flicker at 160 and hear the sounds at 140. Clearly that's quite the difference...

So what do I go by? Technically at the 'flicker', blood is getting past, so therefore the pressure required has been reached.. or am I missing something?

Many thanks
Sam


----------



## 94H (Apr 17, 2012)

The systolic is when you first hear kortokoff's sign and diastolic is when you no longer hear it


----------



## EMSSam (Apr 17, 2012)

94H said:


> The systolic is when you first hear kortokoff's sign and diastolic is when you no longer hear it



Thanks. I'm confused though, because as soon as the needle on the gauge flickers, blood is starting to overcome the pressure of the cuff (even only a little blood), so why wouldn't that be systolic?


----------



## Handsome Robb (Apr 17, 2012)

EMSSam said:


> Thanks. I'm confused though, because as soon as the needle on the gauge flickers, blood is starting to overcome the pressure of the cuff (even only a little blood), so why wouldn't that be systolic?



A lot of things can make the needle flicker. The pt flexing, shivering, twitching, moving for example. 

That's why you listen for the sounds. 

Some people will tell you that you can go off the bounces in a pinch but I don't agree. 

Listen for it. If you really can't hear it palpate it but don't go off the bounce of the needle.


----------



## DesertMedic66 (Apr 17, 2012)

NVRob said:


> A lot of things can make the needle flicker. The pt flexing, shivering, twitching, moving for example.
> 
> That's why you listen for the sounds.
> 
> ...



Agreed. Bumps in the road will cause the needle to flicker. 

Go by what you hear. If you can't hear anything then palp it.


----------



## EMSSam (Apr 17, 2012)

firefite said:


> Agreed. Bumps in the road will cause the needle to flicker.
> 
> Go by what you hear. If you can't hear anything then palp it.



I realise that, but the flicker I'm talking about it that constant, pulse-like flicker that is obviously a little pulse and always happens just before the sounds.

However, I guess I can't really go wrong with the sounds since that seems to be the norm!


----------



## DesertMedic66 (Apr 17, 2012)

The only time I use the flicker is to give me a general idea of when I should start hearing something in the steth.


----------



## Sandog (Apr 18, 2012)

firefite said:


> The only time I use the flicker is to give me a general idea of when I should start hearing something in the steth.



That sounds reasonable.


----------



## CCNRMedic1982 (Apr 18, 2012)

Those initial flickers are the movement of blood past the pressure in the cuff. However, the reason you don't use those as a measure is because when you see the flicker and hear the pulse that is the "true" measure of the pressure in the artery that allows blood flow distal to the cuff. The blood pressure cuff will also pick up blood flow through other vessels in the extremity but the sound comes only from the brachial artery. ( hmm, that was actually a simpler explanation) and auscultated b/p is not 100% accurate. An arterial line with constant b/p readings is the probably most accurate measurement of arterial blood pressure but for what prehospital providers have to do it gets us pretty close.


----------



## EMSSam (Apr 18, 2012)

Thanks for that info everyone!


----------



## AnthonyM83 (Apr 18, 2012)

We don't want a measurement of when the pressure wave of blood is strong enough to bounce the needle, rather we want the measurement of when it's actually flowing through.


----------



## TyBigz (Apr 19, 2012)

At my station there is some controversy over when you hear the bp is it the light thumps for systolic or the bounding thumps that you take for your systolic. Which do you guys take?


----------



## kindofafireguy (Apr 19, 2012)

If I can hear it, I count it.

But the difference between the bounding and the softer sounds shouldn't be that great (say, within 10 mmHg, which is within the margin of error for a BP anyway).

But that's just my opinion. Someone else will probably correct me, or have a much better answer.


----------



## Miscusi (Apr 19, 2012)

alot of people provided alot of reasons to listen for the sounds... but I provide just one reason, the reason to end all if, ands, or buts, that is, because you are told to listen for the sounds..  Did any instructor say anything about looking for needle bumps and jumps ? NO.


----------



## Tigger (Apr 22, 2012)

Miscusi said:


> alot of people provided alot of reasons to listen for the sounds... but I provide just one reason, the reason to end all if, ands, or buts, that is, because you are told to listen for the sounds..  Did any instructor say anything about looking for needle bumps and jumps ? NO.



I wish I had an EMT class where my instructor taught me everything I needed to know about my job and never misspoke or left anything out.:unsure:


----------



## medichopeful (Apr 22, 2012)

Miscusi said:


> alot of people provided alot of reasons to listen for the sounds... but I provide just one reason, the reason to end all if, ands, or buts, that is, because you are told to listen for the sounds..  Did any instructor say anything about looking for needle bumps and jumps ? NO.



But you're also TOLD to give everybody oxygen, right?  So should you?

In medicine, just doing something because you're told to isn't really the best way to go about things.


----------



## EMSSam (Apr 22, 2012)

medichopeful said:


> But you're also TOLD to give everybody oxygen, right?  So should you?
> 
> In medicine, just doing something because you're told to isn't really the best way to go about things.



I quite like that thought - at least if everyone does it the same way, there will be some sort of consistency. 

Not with O2 though!


----------



## Bullets (Apr 22, 2012)

medichopeful said:


> But you're also TOLD to give everybody oxygen, right?  So should you?
> 
> In medicine, just doing something because you're told to isn't really the best way to go about things.



No, thats finally changed, at least for National Registry

Palpate a pulse= BP of at least 80 systolic...tell the nurses that in youre report


----------



## medichopeful (Apr 22, 2012)

EMSSam said:


> I quite like that thought - at least if everyone does it the same way, there will be some sort of consistency.
> 
> Not with O2 though!



Consistency is good, but only to an extent.  If we just mindlessly do what we're told to do, and don't think about the hows and whys, how will the field advance?


----------



## medichopeful (Apr 22, 2012)

Bullets said:


> No, thats finally changed, at least for National Registry
> 
> Palpate a pulse= BP of at least 80 systolic...tell the nurses that in youre report



I'm glad to hear that!  They finally realized oxygen was a drug :wacko:


----------



## EMSSam (Apr 22, 2012)

medichopeful said:


> Consistency is good, but only to an extent.  If we just mindlessly do what we're told to do, and don't think about the hows and whys, how will the field advance?



I guess that's where my initial question came from - considering the physiology behind it all


----------

