COPD, SOA, and a (small) troponin bump... lets talk

[stoic]

Alright, so I haven't seen this pt. yet, but I will tomorrow. He was admitted to the med service I'm rotating on right before quittin' time tonight. He's not my pt, but I'm gonna round on him and follow him for fun 'cause I thought the scenario was a tit-bit interesting. (I'm at the VA so everyone is really sick but somehow still alive.) As I haven't seen the pt yet and we just started ordering labs on the pt tonight, I unfortunately don't have a ton of details yet. Should have more info info tomorrow to aid the discussion... but I wanted to go ahead and post what I know so far and see what everyone thought.

This pt. is a 70 yo male with a long history of severe COPD, CAD, previous MI ("about a decade ago") and PCTA X 4 (the most recent was last march which the pt reports as having showed no worsening disease.) This is the pt's first admission to the VA system, so the bulk of his records are in the private sector and scattered around the country (IE "I think my first cath was done is Houston... wait, maybe Seattle.") He came in from an outlying hospital ED after a workup for SOA that failed to show any likely cause for the pt's Sx other than severe COPD with perfectly classical emphysematous changes on CXR and compensated respiratory acidosis. No consolidation or signs of pneumonia on CXR. Also noted was some questionable cardiomegaly (hard to tell with the barrel chest/displaced diaphragm). The labs sent with the pt from transferring ED were basically normal for a pt in this stage of the COPD process (IE compensated resp. acidosis). Of note was a completely normal troponin of 0.04ng/ml, normal renal function (Cr 1.1, BUN 27).

So... why's this guy interesting? At the VA we got some stat labs on admission... they all agreed with the outlying ED's results EXCEPT for the troponin, which was now 0.6ng/ml. This is still below the cutoff for abnormal, but (to me at least) significantly higher than just a few hours ago at the transferring ED.

Myoglobin and CK were both normal at the VA.

EKG's at both the transferring facility and the VA showed non-specific q-waves and st changes consistent with a previous MI... but because we don't have old EKG's to compare with it's tough to r/o an acute event.

Pt. is NOT experiences chest pain/discomfort but is reporting continued shortness of air. Symptoms do not match those pt recalls from previous MI.


So... I should know a lot more tomorrow after rounding on the pt and having a chance to review the rest of the labs we ordered. But for right now I do have a couple of questions/discussion points:

1. What's up with this troponin bump? We ordered serial enzymes, but the IM team was not impressed with the possibility of this being an acute event. Personally, I have a little bit harder time dismissing the troponin bump as nothing... but I have much less experience than the rest of the team and couldn't really back that opinion up with much more than a gut feeling.

Other causes of troponin bump? CHF can stretch the myocytes and cause "leaky" troponin, right? I don't have a current BNP on the pt and don't know if one was ordered tonight... if not I'll push for it tomorrow. I've heard that renal disease can cause increase troponin levels, but am not aware under which circumstances or by what mechanism. (though I'm not sure that applies here since the pt has no history of renal disease and a fairly normal Cr/Bun).

2. What do you guys want to know? If you post it tonight/tomorrow I'll try my best to get it ordered. I'm only an MS3... but if there's a decent reason for the test, I can probably get it done.

3. What's your gut feeling giving the picture I've laid out so far? I know it's not much... but it's all I have right now. Personally, I think they guy should probably be in telemetry, not on a general med floor... but then again, what do I know... I'm just an MS3

thanks for engaging my elementary discussion,
stoic

ps. I wish we could still write SOB on the charts.

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[bulgethetwine]

1. What's up with this troponin bump? We ordered serial enzymes, but the IM team was not impressed with the possibility of this being an acute event. Personally, I have a little bit harder time dismissing the troponin bump as nothing... but I have much less experience than the rest of the team and couldn't really back that opinion up with much more than a gut feeling.

Other causes of troponin bump? CHF can stretch the myocytes and cause "leaky" troponin, right? I don't have a current BNP on the pt and don't know if one was ordered tonight... if not I'll push for it tomorrow. I've heard that renal disease can cause increase troponin levels, but am not aware under which circumstances or by what mechanism. (though I'm not sure that applies here since the pt has no history of renal disease and a fairly normal Cr/Bun).

2. What do you guys want to know? If you post it tonight/tomorrow I'll try my best to get it ordered. I'm only an MS3... but if there's a decent reason for the test, I can probably get it done.

3. What's your gut feeling giving the picture I've laid out so far? I know it's not much... but it's all I have right now. Personally, I think they guy should probably be in telemetry, not on a general med floor... but then again, what do I know... I'm just an MS3
.

Troponin can be increased in renal failure. Remember it by just thinking that it hangs around longer in renal failure because the kidney has to clear it (not exactly the sole mechanism, but works as a memory aid). Follow the ckMB if you're trending, but always trust the 'clinical picture' i.e. don't dismiss it as elevated solely due to renal failure if it's a good story.

As for the "bump"... it's not really a bump. You're still a long way from significance. Know the different troponins, too, since different ones have different cutoffs (trop-T, trop-C, etc.). AT this level, it's not significant. Also, what was his CKmB?

If you were really worried, order an echo... although this might be difficult at the VA.

I think you're overreacting. This guy, barring any new symptoms or hemodynamic change, should be ruled out and stressed... although he should definately be on telemetry given his history.

 

[Hard24Get]

I am "just" a medical student, too (do you know how many times I got smacked for saying that before I stopped), but I was on pulmonary consult at one time, so here are my contributions:

1. Check out this article: Falsely elevated cardiac troponin I levels.Clin Cardiol. 2007 Feb;30(2):92-4 PMID: 17326064
"This may be observed in several well-known situations including pulmonary embolism, pericarditis, myocarditis, coronary vasospasm, sepsis, congestive heart failure, supraventricular tachycardia with hemodynamic compromise, re-nal insufficiency, and prolonged strenuous endurance exercise. Endogenous antibodies such as heterophile antibodies, rheumatoid factor, and other autoantibodies are known to interfere with the immunoassay measurements of many different analytes, including the widely used Abbot AxSYM cTnI analyzer. Other sources of circulating antibodies include immunotherapies, vaccinations, or blood transfusions that may interfere with these immunoassays as well."
Should be a nice article to share with the team, although the troponin levels are really not abnormal. I wouldn't care either without an elevated CKMB and chest pain, etc

2/3. I guess my gut feeling would be COPD exacerbation - would want to know if he has had a change in sputum, etc. However, he has only had a CXR from your story - without a recent high res CT, he could have worsened emphysema, ILD or another pulmonary process as well (depdending on the read he could have even ruptured a bullae and have a small PTX). Is he on steroids at home? Should we worry about PCP, etc? How bad is the respiratory acidosis? How severe is the desat? How acute was the onset of SOB (we can still say that at our hospital)? Did they do a D-Dimer and whatnot? Would need alot more info including H&P (edema?JVP?), but independent of the story I'd think an echo/bnp would help. He should probably be on tele at least until a cardiac source/PE is excluded. If, as you say, his renal function is fine and he is being admitted for this, I would go straight to the CT-A and assess for PE and less obvious lung pathology at the same time. The key part of history for the differential is how acute it is, I believe.

1. What's up with this troponin bump? We ordered serial enzymes, but the IM team was not impressed with the possibility of this being an acute event. Personally, I have a little bit harder time dismissing the troponin bump as nothing... but I have much less experience than the rest of the team and couldn't really back that opinion up with much more than a gut feeling.

Other causes of troponin bump? CHF can stretch the myocytes and cause "leaky" troponin, right? I don't have a current BNP on the pt and don't know if one was ordered tonight... if not I'll push for it tomorrow. I've heard that renal disease can cause increase troponin levels, but am not aware under which circumstances or by what mechanism. (though I'm not sure that applies here since the pt has no history of renal disease and a fairly normal Cr/Bun).

2. What do you guys want to know? If you post it tonight/tomorrow I'll try my best to get it ordered. I'm only an MS3... but if there's a decent reason for the test, I can probably get it done.

3. What's your gut feeling giving the picture I've laid out so far? I know it's not much... but it's all I have right now. Personally, I think they guy should probably be in telemetry, not on a general med floor... but then again, what do I know... I'm just an MS3

thanks for engaging my elementary discussion,
stoic

ps. I wish we could still write SOB on the charts.

 

[edmachine]

I'm thinking the patient's COPD exacerbation brought on myocardial ischemia, leading to a slightly elevated troponin level.

Tests I'd like to see: CBC, BNP, ABG's (hopefully it was done by the transfering ED), d-dimer, and serial troponins drawn in the meantime. The patient should also be on continuous cardiac monitoring and have a repeat EKG, and should be admitted to a cardiac-tele floor (especially since he has a hx of CAD and previous MI). Depending on what other factors were present, I might draw blood cultures x2.

I once had a COPD patient, A/Ox1 (pt's baseline), complaining of SOB with a hx of CHF. Oxygen sats were around 88% on room air, and the patient had bilat. +3 pitting edema. The patient denied N/V, skin was dry, and denied pain. I was thinking CHF exaccerbation was what was going on and wasn't too concerned (stable, right?). Well, labs came back with a hemoglobin of 4-something (4.3? I can't exactly remember). He too had slightly elevated troponin levels. Needless to say, he received a stat blood transfusion and went up to ICU. This one came out of nowhere - r/o upper GI bleed.

 

[lucky_deadman]

I won't get into what all could be going on with this stereotypical VA patient. I will say that the troponins were drawn at different hospitals and therefore I should be safe in saying different labs. Different labs/equipment come up with different numbers all the time.

One hospital I recently worked at had bedside markers in the ED and ran serials in the lab. It would tend to happen that the same specimen get markers ran by both the ED and lab on the first specimen. Always interesting in the differences (usually much greater than in this case).

 

[deleted109597]

troponinoma. That's my guess.

 

[Seaglass]

What the hell is SOA?

 

[Hard24Get]

What the hell is SOA?

SOA=SOB Political-correctness strikes again!

 

[kungfufishing]

Maybe meant OSA?

 

[12R34Y]

You shouldn't compare lab results among different institutions. Some measure Trop-T other Trop-I, hospitals frequently have different normal ranges and their machinery may not be the same. d-dimers are VERY instiutional dependant as well.

Generally, unless the troponin was obviously high at the outside place you have start from your facility with things that are so sensitive/specific.

Hb/Hct, BMP's etc... you could probably trust more, but i wouldn't worry.

If this is truly cardiac and he has NO EKG changes by morning and his troponin stays the same then unlikely primary cardiac event. Although he does have a significant history and he definatately will need stressed at some point to evaluate heart.

troponins "bump" all of the time and most of the time it isn't a big deal. They get a stress and go bye-bye.

later

 

[roja]

Troponin can be increased in renal failure. Remember it by just thinking that it hangs around longer in renal failure because the kidney has to clear it (not exactly the sole mechanism, but works as a memory aid). Follow the ckMB if you're trending, but always trust the 'clinical picture' i.e. don't dismiss it as elevated solely due to renal failure if it's a good story.

As for the "bump"... it's not really a bump. You're still a long way from significance. Know the different troponins, too, since different ones have different cutoffs (trop-T, trop-C, etc.). AT this level, it's not significant. Also, what was his CKmB?

QUOTE]


We used to get alot of the 'don't mind the troponin, they aer a dialysis patient' until the ED residents started giving out copies of this article:

http://www.chestjournal.org/cgi/reprint/125/5/1877.pdf


many things can cause a positive troponin. However, in the right patient, you must treat it seriously.


Just thought others might like this article.

 

[docB]

Check out this article: Falsely elevated cardiac troponin I levels.Clin Cardiol. 2007 Feb;30(2):92-4 PMID: 17326064
"This may be observed in several well-known situations including pulmonary embolism, pericarditis, myocarditis, coronary vasospasm, sepsis, congestive heart failure, supraventricular tachycardia with hemodynamic compromise, re-nal insufficiency, and prolonged strenuous endurance exercise. Endogenous antibodies such as heterophile antibodies, rheumatoid factor, and other autoantibodies are known to interfere with the immunoassay measurements of many different analytes, including the widely used Abbot AxSYM cTnI analyzer. Other sources of circulating antibodies include immunotherapies, vaccinations, or blood transfusions that may interfere with these immunoassays as well."

If you have a patient with any of these conditions are the elevated troponins really "false" or are they elevated due to something besides ACS? I would argue that trops elevated due to myonecrosis secondary to other causes are real.

 

[Hard24Get]

If you have a patient with any of these conditions are the elevated troponins really "false" or are they elevated due to something besides ACS? I would argue that trops elevated due to myonecrosis secondary to other causes are real.

A great point - the article says "falsely" but I think they meant "other than atherosclerotic MI", ie cath lab and anticoagulation won't help. The only one that seems truly false are the antibodies messing up the ELISA. The rest of the conditions are killing myocytes. I have tried to point that out on IM rounds before and no one seemed to agree.