When to order an EKG for tachycardia

[Rendar5]

Had a patient the other day with a pulse in the 120s-130s. Clear-cut sinus tachy from a bad fever and pain, but I asked for an EKG anyway just to make me feel better. The patient looked sick and was pregnant, H&P suggested viral syndrome vs pyelo vs septicemia. For some stupid reason, i wanted to also just chop myocarditis off the differential).

My broader question is: when are EKGs called for when it just comes to abnormal vitals and when are they not? And is there any set formula to know what appropriate HR elevation is in relation to fever?

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[WilcoWorld]

When you've treated the fever/dehydration/anxiety/pain that you suspect is the cause & the tachycardia hasn't resolved, or when they have significant comorbidity (DM, CAD, COPD) that predisposes them to "bad" causes of tachycardia.

Also, when your spidey sense (or your attending) tells you to get one, just get one.

 

[SoCuteMD]

Had a patient the other day with a pulse in the 120s-130s. Clear-cut sinus tachy from a bad fever and pain, but I asked for an EKG anyway just to make me feel better. The patient looked sick and was pregnant, H&P suggested viral syndrome vs pyelo vs septicemia. For some stupid reason, i wanted to also just chop myocarditis off the differential).

My broader question is: when are EKGs called for when it just comes to abnormal vitals and when are they not? And is there any set formula to know what appropriate HR elevation is in relation to fever?

I learned that an appropriate response is 10 bpm for every degree CELSIUS increase in temperature.

 

[leviathan]

I learned that an appropriate response is 10 bpm for every degree CELSIUS increase in temperature.

Wow...HR can't really go up that much then just from temperature.

 

[deleted109597]

Here's one. If they came to the ED because of tachy, then they earn the EKG.
Either way, if they're real sick, they might also have a cardiac compenent to their disease, and you can't be faulted for ordering it on someone who is borderline SIRS.

 

[SoCuteMD]

Wow...HR can't really go up that much then just from temperature.

There is a significant increase in metabolic demand associated with an increase in temperature. Not to mention the vasodilation that occurs also increases HR in order to perfuse adequately.

 

[Mighty Mouse]

my attending once told me, "never talk yourself out of an ekg." my feeling is, tachycardia is an abnormal vital sign. i may not be likely to get one on a 25 year old with a HR of 110, but if its a person with some cardiac risk factors coming in with some other chief complaint and they're tachycardic, I'd probably get an EKG. the only thing quicker and cheaper in the ED is oxygen.

 

[southerndoc]

Wow...HR can't really go up that much then just from temperature.

What almost always accompanies fevers? Dehydration.

Couple the two together, and someone who has a temp of 103 can easily have a heart rate of 140 that comes down to 80 with defervescence and rehydration.

 

[roja]

I order an EKG for tachy when I think there is a possibility that it is related to a cardiac abnormality.

A young person with obvious dehydration and infection? Probably not. I would treat/hydrate etc and *then* if the HR doesn't come down, consider an EKG.

Using tests to make yourself feel better is a great way to potentially hurt your patient or you.

Order the test when you think you need an EKG: PE, arrythmia, etc.

 

[FLTDOC1]

FYI -

Between interpretation and facility costs, the bill for a single 12 lead EKG is $150-$200.

 

[Rendar5]

Wow seriously? I was under the impression that it was one of the cheaper tests you can perform. Definitely something to think about.

 

[Rendar5]

I order an EKG for tachy when I think there is a possibility that it is related to a cardiac abnormality.

A young person with obvious dehydration and infection? Probably not. I would treat/hydrate etc and *then* if the HR doesn't come down, consider an EKG.

Using tests to make yourself feel better is a great way to potentially hurt your patient or you.

Order the test when you think you need an EKG: PE, arrythmia, etc.

Actually that brings up another question I had. How useful are EKGs for diagnosing/ruling out PEs or for managing them? I was under the impression that obvious EKG signs of PE don't show up that often.

 

[deleted109597]

Actually that brings up another question I had. How useful are EKGs for diagnosing/ruling out PEs or for managing them? I was under the impression that obvious EKG signs of PE don't show up that often.

Most common EKG finding of PE? Sinus tach.
S1Q3T3, or any other variant of cor pulmonale, less than 25%.

 

[southerndoc]

Wow seriously? I was under the impression that it was one of the cheaper tests you can perform. Definitely something to think about.

Actually it is still one of the cheaper tests you can perform.

 

[FLTDOC1]

Actually it is still one of the cheaper tests you can perform.

Compared to radiology , yes( CT abd/pelv w contrast-$3500)- but still 3-5x the cost of most "lab" tests ( UA - $30, CBC-$45, BMP-40$, Upreg-$30, blood cx - $50)

 

[roja]

an ekg doesn't rule in or out a PE. The s1q3t3 is rare and can be present in someone that doesn't have a pe.

Other things that add into your clinical picture of PE that *might* help: Sinus Tach, right heart strain (if its big), rarely, arrythmias

 

[emtcsmith]

It really shouldn't be that complicated...I don't know your situation and specifics but its only an EKG not a central line if you think you want one, order it.

 

[12R34Y]

There is a significant increase in metabolic demand associated with an increase in temperature. Not to mention the vasodilation that occurs also increases HR in order to perfuse adequately.

I know this is really dorky (but I seriously JUST read this).

Rosen's says that for every .55degree celsius increase there is an increase in 10 of the heart rate.

seriously, i know.........big dork.

later

 

[SoCuteMD]

I know this is really dorky (but I seriously JUST read this).

Rosen's says that for every .55degree celsius increase there is an increase in 10 of the heart rate.

seriously, i know.........big dork.

later

I'm glad you found the number - I couldn't find it!

 

[leviathan]

What almost always accompanies fevers? Dehydration.

Couple the two together, and someone who has a temp of 103 can easily have a heart rate of 140 that comes down to 80 with defervescence and rehydration.

Good point...I often see febrile people in the 130s-140s so there certainly is a discrepancy there.

 

[WallowaWanderer]

FYI -

Between interpretation and facility costs, the bill for a single 12 lead EKG is $150-$200.

Is that what is billed or what hospitals collect for an EKG? Seems like the latter number is what we should look at when we are considering the "cost" of a test.

 

[FLTDOC1]

Is that what is billed or what hospitals collect for an EKG? Seems like the latter number is what we should look at when we are considering the "cost" of a test.

If you want to base your "cost" on what hospitals/physicians collect - a lot of our health care would be considered free.

 

[roja]

It really shouldn't be that complicated...I don't know your situation and specifics but its only an EKG not a central line if you think you want one, order it.

Your right, its not an EKG. However, that doesn't mean it should be indiscriminately ordered. If you had an older patient who tripped on thier shoe laces and had an ankle sprain/fracture (non operable) that is going to go home but came in with a HR of 110 because of pain, you wouldn't order an EKG (in fact, most attendings with more than a year or more of experience will scream to keep the machine away). The reason is that an EKG is rarely stone cold normal (and in the right clinical picture, it doesn't matter if it is...just as a tangential aside).

So, if you *get* an ekg that isn't absolutely normal, you may find yourself in a position where you are having to deal with an ekg in a patient who has absolutely no cardiac issue.

So, if you have a clinical reason, you should get one.

If you don't, you shouldn't order one.

(An extreme example of this that one of our attendings likes to use is ordering a pregnancy test in a young male with abdominal pain. You know its going to be negative, but it could come back positive. and if it does, what are you going to do now? ignore a 'positive' test that you ordered? do more work up that you know will be negative but that you are stuck doing because you ordered a test when you didn't need one)

 

[jbar]

(An extreme example of this that one of our attendings likes to use is ordering a pregnancy test in a young male with abdominal pain. You know its going to be negative, but it could come back positive. and if it does, what are you going to do now? ignore a 'positive' test that you ordered? do more work up that you know will be negative but that you are stuck doing because you ordered a test when you didn't need one)

Maybe this is because I'm studying for boards and losing my mind, but isn't there some tumor that men can get that secretes hCG and therefore would have a positive test? Semenoma or something like that? I know its not really EM but just to be devils advocate.

 

[FLTDOC1]

To sum it up, when it comes to any ancillary testing ( lab, rads, micro)

Dont ask questions you dont want answered



Rule #3 or 4 of EM - all abnormal lab values and vital signs must be addressed

If you draw a chem-2500, get an ecg and a urine on 20 asymptomatic 85 year olds - at least 20% or your results will be abnormal. The majority of these positives will be false positives. But it is now your job to prove they are false positives

 

[southerndoc]

Maybe this is because I'm studying for boards and losing my mind, but isn't there some tumor that men can get that secretes hCG and therefore would have a positive test? Semenoma or something like that? I know its not really EM but just to be devils advocate.

Yes, a seminoma can secrete HCG. I think a fifth of them do. Most HCG secreters are trophoblastic, non-seminomatous, or choriocarcinomas though. 100% of choriocarcinomatous tumours will secrete HCG.

If you tell my colleagues I knew this, I will strangle you the next time I see you! (I'm a path freak.)

 

[nymbarra]

A bit off-topic, but curiosity got the better of me:

Maybe this is because I'm studying for boards and losing my mind, but isn't there some tumor that men can get that secretes hCG and therefore would have a positive test? Semenoma or something like that? I know its not really EM but just to be devils advocate.

From the Natl Cancer Institute SEER website:

"Used as a tumor marker for choriocarcinoma and for testicular carcinoma. Beta-HCG levels are never found in normal men. When the presence of B-HCG is detected in serum it always indicates a malignancy...In patients with testicular cancer who have had an orchiectomy, the presence of beta-HCG will confirm the patient has residual cancer that requires further treatment. However, when beta-HCG does not exist in the serum, the presence of active cancer cannot be excluded, especially in patients who have been previously treated."

Don't know how specific it is for malignancy in men, though, the "always" red flag withstanding. Malignancy-wise, can be secreted in any germ cell tumor, and has been reported in pineal gland teratomas!

 

[roja]

Yes, a seminoma can secrete HCG. I think a fifth of them do. Most HCG secreters are trophoblastic, non-seminomatous, or choriocarcinomas though. 100% of choriocarcinomatous tumours will secrete HCG.

If you tell my colleagues I knew this, I will strangle you the next time I see you! (I'm a path freak.)

dies laughing

 

[leviathan]

Maybe this is because I'm studying for boards and losing my mind, but isn't there some tumor that men can get that secretes hCG and therefore would have a positive test? Semenoma or something like that? I know its not really EM but just to be devils advocate.

Exactly...so if you had a +++ test for hCG in a man, then you would have to investigate it further to rule out malignancy. Of course that might not be the best example, because assuming it is an accurate test, that would mean you caught it and could start treatment on someone...which would actually be a good thing. I'm rambling, so I'm going to go to bed.

 

[Seaglass]

Compared to radiology , yes( CT abd/pelv w contrast-$3500)- but still 3-5x the cost of most "lab" tests ( UA - $30, CBC-$45, BMP-40$, Upreg-$30, blood cx - $50)

Those are the "costs" of the test - not the patient charge. The patient is going to be charged ~$100 for any one of those tests. The EKG hardly "costs" anything but the patient charge is significant.

 

[Strength&Speed]

ah forget it