BP - Auscultation over Radial?

[icekayak]

Someone asked me a question today...
They had a patient that couldn't bend their arm so had trouble getting the steth over the brachial artery and just put it over the radial artery and took the blood pressure by auscultation over the radial artery.

Does anyone know how accurate this would be?

 

[rmellish]

Did they have the cuff around the forearm as well?

 

[Jon]

Why not palp it?

 

[skyemt]

palp has proven to be relatively inaccurate...

in addition, large auscultory gaps can be missed using palp...

it's better than nothing, but not by a whole lot...

 

[mikie]

During my ER clinical, a pt said we couldn't take her BP on her arms because of a double mastectomy (the reason why about the BP, I don't know), so I was told to use a child cuff over the wrist and take it same w/ as if Brachial

 

[Ridryder911]

During my ER clinical, a pt said we couldn't take her BP on her arms because of a double mastectomy (the reason why about the BP, I don't know), so I was told to use a child cuff over the wrist and take it same w/ as if Brachial

You should have been taught this in your basic. Mastectomies as well as those of dialysis, CVA patients and some other conditions, cannot have a blood pressure as well as venous punctures performed on those extremities that is affected.

In radical mastectomies the lymph nodes is removed and vasculature is changed, the squeezing can cause damage as well as veinapuncture, from the lymph fluid.

R/r 911

 

[mikie]

You should have been taught this in your basic. Mastectomies as well as those of dialysis, CVA patients and some other conditions, cannot have a blood pressure as well as venous punctures performed on those extremities that is affected.

In radical mastectomies the lymph nodes is removed and vasculature is changed, the squeezing can cause damage as well as veinapuncture, from the lymph fluid.

R/r 911

I never learned about the mastectomies related issues, so thanks for clearing that up. We were however taught about the BP placement in dialysis and CVA patients.

Thanks

-just for clarification though, auscultation over the radial does work, correct?

 

[Jon]

I never learned about the mastectomies related issues, so thanks for clearing that up. We were however taught about the BP placement in dialysis and CVA patients.

Thanks

-just for clarification though, auscultation over the radial does work, correct?

Dialysis patients often have shunts... but why can't you get a B/P on a CVA patient? Active CVA, or S/P CVA? which side?


And Rid... c'mon... you KNOW that basics learn almost nothing in school... same as paramedics. Almost all of the useful stuff I've learned has been from co-workers, Con-Ed/conferences, and discussions in places like this.

Jon
- - - - - - - - PS... this is not a bash at BLS providers (I AM one)... just the sad truth. - - - - - - - -

 

[Ridryder911]

Here ya go.... Removal of lymph nodes may affect the drainage of lymphatic fluid from the arm on the surgical side. Problems with lymphatic drainage may result in arm swelling and an increased risk for infection from trauma to the arm. In addition, there is an increased risk for blood clots in the blood veins of the armpit because of surgical trauma in the area.... the same is true in patients with a CVA or immobile extremity.

Dialysis shunts are a dangerous thing to place pressure on and as well hopefully no needles around the shunt..

R/r 911

 

[icekayak]

Some interesting replies there thanks
I didn't ask but i presumed they placed the cuff in the normal place.

I guess as the artery is further away from the cuff there may be less defined sounds as the blood has more time to diffuse after passing through the cuff.. and i guess you would have to let the cuff down slower as it takes a fraction longer for the blood to reach the radial than the normal brachial?

 

[Ridryder911]

Some interesting replies there thanks
I didn't ask but i presumed they placed the cuff in the normal place.

I guess as the artery is further away from the cuff there may be less defined sounds as the blood has more time to diffuse after passing through the cuff.. and i guess you would have to let the cuff down slower as it takes a fraction longer for the blood to reach the radial than the normal brachial?

Not really, as well you are not hearing the sounds of the brachial rather the radial, as well if the BP is to be taken on or at the radial, then the cuff should be placed on the forearm, so it is closer to the artery.

R/r 911

 

[Ops Paramedic]

With regards to your question on the accuracy, i don't believe it will be (as described, providing the cuff was placed superior to the elbow, and then auscultating over the radials).

There is a drop in BP by roughly 10mmHg when palpating/ausciltating the brachial artey vs that of the radial artery. As for being able to ausciltate Korotkoff sounds over the radial artery, i would'nt know, and have not tried it yet. I can only imagine that hey will be fairly diminshed, if at all audible. If the cuff was placed just superior to the radial artery, then remember to change the size of cuff used as mentioned.

Hoping the info helped a bit...

 

[icekayak]

Here's a piece from a AHA Scientific Statement (2005)
http://hyper.ahajournals.org/cgi/content/full/45/1/142 (Roughly half way down page)

It is taking about obese patients:
"In the rare patient with an arm circumference >50 cm, when even a thigh cuff cannot be fitted over the arm, it is recommended that the health care practitioner wrap an appropriately sized cuff around the patient’s forearm, support it at heart level, and feel for the appearance of the radial pulse at the wrist. Other potential methods for measuring radial artery pressure include listening for Korotkoff sounds over the radial artery, detecting systolic pressure with a Doppler probe, or using an oscillometric device to determine systolic blood pressure; diastolic blood pressure is largely overestimated by both methods.156 The accuracy of these methods has not been validated, but they provide at least a general estimate of the systolic blood pressure."

 

[Hastings]

It may be less accurate than more traditional means, but palpating at the radial is still going to be more accurate than trying to listen at the at the same location.

 

[Ridryder911]

It may be less accurate than more traditional means, but palpating at the radial is still going to be more accurate than trying to listen at the at the same location.

How is a palpation more accurate? When especially you are getting only an approximate systolic only?

 

[TKO]

Here's another suggestion, grab your partner and a few others and practice it for yourself. Check normally and then by palp, then move the cuff down to the forearm and check palp and auscultate. Give a minute or two between efforts.

Then post your observed results here.

 

[Kimmy Schaub]

Why didn't he use the unaffected arm? He could have just palpated it because placing the steth over the radial artery is not very accurate.

 

[Ridryder911]

Why didn't he use the unaffected arm? He could have just palpated it because placing the steth over the radial artery is not very accurate.

Who says the radial artery is not accurate? Really folks, an arterial reading is an arterial reading. Where do you think they place art lines at? Remember, palpation is nice; but it is a only an educated guess of only what the systolic.

R/r 911

 

[MSDeltaFlt]

Not to mention there are three readings on a blood pressure that are important:

Systolic
Diastolic
Mean Arterial Pressure (MAP)

The MAP is more important than some may realize, and you cannot get it with a palpated BP. NIBP's are not accurate. They are only for trends. The manufacturer's literature of the BP machine will tell you they're not accurate. The only accurate BP's you can get are auscultated BP and a properly zeroed arterial line.

To calculate MAP is sys + dia + dia/3. Will you have time to calculate that enroute to ER? No. But the ER will have the information at their disposal.

I personally don't like palpated BP's. If your pt is so critical you don't have time to auscultate the BP then you only have time to palpate pulses; if and only if you're not "hung" further up on the ABC's.

If they're HYPERtensive and critical, then you will need BOTH sys and dia BP's. BP by palp is useless. If your pt is HYPOtensive and critical, then you need to know where you can and cannot feel a pulse. Again, BP by palp is useless; kinda like mammary glands on male swine.

Just my humble opinion.

 

[mikie]

Another thing about the palp. vs. auscultation...

What about the pulse-pressure- you can't get that via palp.? I recall learning about that, but not in enough detail. Could someone give some more detail about it and its use for 'us' (prehospital providers)?