Shortness of Breath in the pregnant patient: what's your approach?

[vengaaqui]

So I saw this patient today and am having second thoughts (too late I know but nonetheless) and would love to hear what others are doing.

Youngish female, second trimester, short of breath x 2 days, worse lying flat, better on side. Reports feeling chest congestion, dry cough. No frank chest pain but feels tight. No runny nose, sore throat, yaddy yaddy. No leg swelling, calf pain. no fevers.

Exam noted for wheezing in lower lung base. Otherwise clear. No evidence of volume overload anywhere or calf tenderness. Vitals normal aside from an isolated HR on EKG to 103 (grr). Otherwise EKG fine. CXR clear. I swabbed her with respiratory viral panel looking for flu. No baby complaints. Gets albuterol. Feels better from the dyspnea standpoint/patchy wheezing gone. Wants to go home. Talk about getting CTA for PE, but decide with patient against it as she's feeling better. Return precautions, fu discussed. Then of course diagnose a PE later in the day with evidence of right heart strain in a post-op patient with pretty much the same symptoms and vitals and exam except having the post op part.

Do you just scan these ladies with SOB in pregnancy? Do you have a more nuanced approach since there's no clear decision rule and elevated d dimer thresholds while cool aren't really validated? Do you VQ them for the risk of radiation in mom's breast tissue? Do you say f-it and have a beer instead of replaying it on a Friday night?

---

Members don't see this ad.

 

[Boatswain2PA]

Unstable = TPA or CT vascular for thrombectomy.

Stable = look closely at ekg for s1q3t3, d-dimer, echo, and VQ scan. If even a little suspicious then start heparin.

Admit all of them.

 

[Arcan57]

Unstable = TPA or CT vascular for thrombectomy.

Stable = look closely at ekg for s1q3t3, d-dimer, echo, and VQ scan. If even a little suspicious then start heparin.

Admit all of them.

I strongly disagree with your last sentence. I also disagree with routine echo and V/Q vs. CTPE is going to depend on a variety of factors. Third trimester or post-partum have a hugely increased risk of PE. First and second trimester have a mild bump in risk and if the dimer is negative in the absence of other reasons for thrombophilia you can stop. I'd probably still stop with stable vital signs and a HR <110 with neg. d-dimer in the 3rd trimester. Also, current recommendations would be to start the "I really need to know if there's a clot" work-up with B LE dopplers.

 

[DrDrummer]

I was just reading and writing about this, randomly. Finishing my OB month and saw a ton of women in triage with vague chest pain, tachypnea, tachycardia. Sorry in advance for the wall of text.

I like the approach published in two sequentially-published review articles by the PE guru Jeff Kline et al., in which they review the diagnostic dilemma presented by these patients and present the following algorithm:

Note the inclusion of the trimester-stratified quantitative d-dimer for patients without a high pretest probability who are PERC negative -- this goes against the conventional wisdom that the d-dimer is a worthless test in pregnant women due to the normal elevation found intrapartum. Similar to the way we have begun “age-adjusting” the threshold value of the quantitative d-dimer in non-pregnant patients, they propose that the threshold be “adjusted according to the trimester of pregnancy, as follows: first trimester, 750 ng/mL; second trimester, 1000 ng/mL; third trimester, 1250 ng/mL (assuming a standard cutoff of 500 ng/mL). If the patient has a non-high-pretest probability, has no high-risk features, is PERC negative, and the bilateral ultrasound is negative, and the D-dimer is below the trimester-adjusted values, PE can be ruled out to a reasonable degree of medical certainty.”

They acknowledge the limitations of this approach, including that it hasn’t been prospectively validated, and they do not present any data showing its performance as they’ve been using it (they have in other articles), but in cases like this expert opinion is the best we have so far, along with some limited retrospective data sets. From the limited background reading I did, it seems like it's more or less congruent with retrospective data out there already.

What I found interesting about this was that the post-partum period is the most risky period of time for women in terms of pulmonary embolism -- this echoes what we know about cardiovascular disease in the post-partum period, i.e. when women are autotransfused and their cardiopulmonary physiology is rapidly and massively altered, presenting the highest for women with heart failure, valvular abnormalities, or disease entities like peripartum cardiomyopathy. According to the data presented by Kline et al, while the risk increases throughout a pregnancy, 70% of all peripartum PEs occur post partum, and the risk during pregnancy itself is relatively low (OR 0.4-0.8, depending on trimester). That said, this may not actually reflect that pregnancy is protective against PE but instead suggest that we overtest women for pulmonary embolism during pregnancy, perhaps because of the clinical changes described above or fear of litigation or something else related to their being pregnant. The also cite a large meta-analysis of 23 epidemiologic studies that found PE occuring in only 3 of 10,000 pregnancies. It might also be that the period of sitting around associated with being postpartum or post-op in the case of a C/S is what confers the relatively larger risk.

Anyway, just one EM intern's opinion and approach so far. It is interesting to me how Jeff Kline (someone who said in a grand rounds he gave that he does a lot of expert witness work) used language in this article such as this: "Recommendations herein suggest decisions and actions that a reasonably diligent and prudent emergency physician should render when caring for patients in a full-service emergency department (ED). If our recommended actions are not available at the initial site of care, this may require patient transfer to a hospital that can provide a higher level of care. However, our recommendations do not necessarily define the sole standard of care, nor do we describe all possible decisions and actions that could be considered reasonable and prudent."

Very legal-ish.

 

[Boatswain2PA]

I strongly disagree with your last sentence.

Sorry, meant admit all that you started heparin.

 

[shoal]

Boatswain... You're fair too pragmatic. Tpa is not approved during pregnancy for one... Look at Jeff Klines decision tree,bits far more complex, and I don't necessarily follow it as I feel 1st and 2nd trimester risk of PE is much closer to the general population and discuss risks benefits and alternatives with the patient and family. If tachycardic I explain that risk as well and give them an official recommendation which is usually image, but often they decide not to. Good luck, always easier to do more and not always do what's right for the patient.


Sent from my iPad using Tapatalk

 

[gman33]

One problem I have is that many of these pt get sent in by their ob to eval for pe.

When that is on the chart i order a ct unless the pt refuses. I still do talk to the pt about the risk/benefit.

 

[Boatswain2PA]

First - sorry for jumping to the post here. I was on my phone and for some reason I thought I was on the PA boards. I usually just lurk here to learn from all of you.

RE this patient - she fails PERC and Wells. Agree D-dimer isn't perfect, but it's something. Likewise POCus isn't perfect (at least not when I'm doing it), but if I see right heart strain then it's strongly predictive of something wrong.

I consider this a can't miss dx. Yes, most people with submassive PEs have them dissolve without treatment, and the study that led to our treatment of PE with heparin is ridiculous. But I don't want Dr. Rosen to be on the witness stand, with his textbook in hand, telling the jury that I should have caught that PE that killed this young mom and her baby. The payoff in that lawsuit would far exceed my malpractice coverage.

Plus, I work in a great environment where it's easy to just admit to obs and let the hospitalist sort it out.

And lastly, while TPA may not be approved in pregnancy, if I have an unstable pregnant woman with history of dyspnea, TPA will be drawn up and ready to push.

 

[coachB]

Others have already thoroughly discussed possible approach to PE work up. Given your story, I'm probably just as concerned for a cardiomyopathy (although a little early) and I think both seem very unlikely.

 

[TooMuchResearch]

Boatswain... You're fair too pragmatic. Tpa is not approved during pregnancy for one... Look at Jeff Klines decision tree,bits far more complex, and I don't necessarily follow it as I feel 1st and 2nd trimester risk of PE is much closer to the general population and discuss risks benefits and alternatives with the patient and family. If tachycardic I explain that risk as well and give them an official recommendation which is usually image, but often they decide not to. Good luck, always easier to do more and not always do what's right for the patient.


Sent from my iPad using Tapatalk

I'd use it in the sick pregnant PE.

 

[Zebra Hunter]

Just get the CTA if you suspect it and you and the mother can both stop stressing. Also, V/Q scan exposes the fetus to more radiation than a CTA.

 

[Boatswain2PA]

Just get the CTA if you suspect it and you and the mother can both stop stressing. Also, V/Q scan exposes the fetus to more radiation than a CTA.

I did not know that, thank you. Quick pubmed search shows you are right, although these authors still suggest VQ > CTA due to breast tissue radiation. http://www.ncbi.nlm.nih.gov/pubmed/20920634

Of course, the few VQ scans I've ever seen were inconclusive anyway.

 

[pianoman511]

ACOG recommends V/Q although higher risk of radiation to the fetus. While CTA has greater radiation to breast tissue, how many ctas do we do to nonpregnant patients and we don't think twice?

Sent from my SM-G925P using SDN mobile

 

[gman33]

The interpretation of the v/q scan can be problematic. I'd rather just get the ct and call it a day.

 

[swamprat]

CTA if I'm concerned about PE. Like gman and others have said, it'll end up being intermediate probability and your back to square one. In additon, radiation exposure worse for V/Q than CTA which was news to me until several months ago.

 

[Groove]

Perc only if my pretest prob is <15%. Don't forget that both perc and wells force a clinical gestalt though perc is more subtle. If your pretest is high then just consent them and spin them up. I have a thorough discussion with the mom about radiation exposure and risks/benefits and document it well along with written consent. I've had to do quite a few of these over the years and am very comfortable in my approach. I've caught PE and another that comes to mind was a mother with undiagnosed advanced lymphoma that got dx with the CTA. You just can't miss a PE in these patients so don't be afraid to rule it out aggressively if warranted. Agree that CTA>VQ. What are you going to do with "low prob" VQ? At the very least get the adjusted dimer. Just remember that if your pretest is high, the longer you dick around trying to avoid the definitive test, the longer you delay a potentially life threatening dx.

 

[sum dude]

I did not know that, thank you. Quick pubmed search shows you are right, although these authors still suggest VQ > CTA due to breast tissue radiation. http://www.ncbi.nlm.nih.gov/pubmed/20920634

Of course, the few VQ scans I've ever seen were inconclusive anyway.

I usually start with D-dimer, if over 0.5, get US and CXR. How do you PERC-out a pregnant patient--they have endogenous hormone in system (same hormone in most OC's.) Then I give informed consent--risks vs benefits, and document well. If sats are 98% and stable VS's and neg. US LE's, then come-on, they're not having a life-threatening PE. If they don't want radiation, they can sign refusal and document well.

If you do scan, why bother with VQ scan? With shielding, less radiation to fetus in CTA--don't give me breast tissue argument--we'd scan a + D-dimer in drop of a hat on non-pregnant patient. VQ scans after hours are an act of deity in my shop after hours, so easier to get CTA. What do you do with a an indeterminate VQ? (answer, get CTA.)

And if they're dying from PE, who cares about FDA approval for TPA? It's like nurses who complain about using a HD catheter-line during a code--what's the risk? Dead mother = dead fetus.

My $0.02

 

[GeneralVeers]

I wouldn't use TPA on a pregnant patient unless I was in contact with an OB/GYN who gave me explicit recommendation to give. That way I can chart it, and document it, so that I'm protected in case of any fetal badness.

 

[Boatswain2PA]

Perc only if my pretest prob is <15%. ......

Do you mentally assign a pretest probability percentage for every patient/test? I just do a gestalt thing...very low, low, crap I have no idea, high, and I'm pretty dang sure it's gonna be positive. I would say <15% would be equal to my low, but I rarely think in absolute percentages like this. Do you? Do you document your estimated pretest prob percentage? (I document "doubt PE, doubt dissection")

I wouldn't use TPA on a pregnant patient unless I was in contact with an OB/GYN who gave me explicit recommendation to give. That way I can chart it, and document it, so that I'm protected in case of any fetal badness.

You take time to do this on a crashing patient? (which is the only time I would give TPA to a pregnant patient). Serious question.

 

[Groove]

Do you mentally assign a pretest probability percentage for every patient/test? I just do a gestalt thing...very low, low, crap I have no idea, high, and I'm pretty dang sure it's gonna be positive. I would say <15% would be equal to my low, but I rarely think in absolute percentages like this. Do you? Do you document your estimated pretest prob percentage? (I document "doubt PE, doubt dissection")

If you're neg LR is 0.17 or PT < 15% only then can you arrive at PERC'd out ~2% risk. The overall point is that gestalt trumps all and these algorithmic approaches are supposed to "force" gestalt before you even get started. My "low" is < 15% and anything more is not worth a PERC. It's a common teaching point for residents to answer the age old "Why not dimer everyone first?". Essentially, your risk is going to be > 2% when your pretest is high (or anything other than "low"), regardless of PERC and you are delaying prompt diagnosis and disposition for a potentially emergent dx. I wouldn't mentally masturbate over the numbers. The overall point is don't bother with PERC if your suspicion is not "low". And most certainly don't use PERC to "get out of" scanning a pregnant pt when PE was near the top of your ddx.

 

[GeneralVeers]

Do you mentally assign a pretest probability percentage for every patient/test? I just do a gestalt thing...very low, low, crap I have no idea, high, and I'm pretty dang sure it's gonna be positive. I would say <15% would be equal to my low, but I rarely think in absolute percentages like this. Do you? Do you document your estimated pretest prob percentage? (I document "doubt PE, doubt dissection")

You take time to do this on a crashing patient? (which is the only time I would give TPA to a pregnant patient). Serious question.

Yep. I wouldn't push TPA on a pregnant patient even if crashing unless I had confirmation of PE. To do otherwise is a one way ticket to LitigationLand.

 

[Boatswain2PA]

Groove - thank you, we're on the same page.

General - Thanks. I'll tuck that one away. Hope I never have to do it (of course, I'm sure I just cursed myself)

 

[Angry Birds]

CTA is less radiation to fetus than VQ scan, as mentioned above.

Speaking of, is there any real use for VQ scan any more? Maybe CKD, but how often in CKD patient are you going to have a normal chest x-ray, which is what you need to interpret a VQ scan, right?

What do you do then in a CKD patient? I had one approach in mind, but I wanted to see what others think first.

 

[maxxor]

CTA is less radiation to fetus than VQ scan, as mentioned above.

Speaking of, is there any real use for VQ scan any more? Maybe CKD, but how often in CKD patient are you going to have a normal chest x-ray, which is what you need to interpret a VQ scan, right?

What do you do then in a CKD patient? I had one approach in mind, but I wanted to see what others think first.

Rads Resident Here:
CTA is definitely less radiation to the fetus compared to VQ.

My nucs department basically finds VQ worthless, and they were a PIOPED site... They ARE used for quantitative analysis for lung resection/etc.

CKD patients can be scanned now with low-contrast-volume scans on dual energy scanners. Talk to your rads about if they are planning to roll it out. We just rolled it out for our ED/inpatients and use < 20 cc contrast on Siemens DE CT.

 

[Angry Birds]

Rads Resident Here:
CTA is definitely less radiation to the fetus compared to VQ.

My nucs department basically finds VQ worthless, and they were a PIOPED site... They ARE used for quantitative analysis for lung resection/etc.

CKD patients can be scanned now with low-contrast-volume scans on dual energy scanners. Talk to your rads about if they are planning to roll it out. We just rolled it out for our ED/inpatients and use < 20 cc contrast on Siemens DE CT.

Thanks for your input.

I currently work at a very small rural hospital, and had a patient with CKD in the middle of night, and I had to rule out PE. I informed the radiology tech that I intended to do a CTA with low contrast and that I would consent the patient, explaining risks and benefits. About ten minutes later I got a call from a very grumpy angry radiology attending, who yelled at me over the phone saying that he absolutely refused to do a CTA scan on a patient with CKD. He told me that I was absolutely crazy for thinking of doing a CTA on a CKD patient and didn't I know any better!?

Anyways, although I knew he was wrong, I didn't know some specifics which would have helped me:

(1) Is there a certain cut off for Creatinine clearance under which you can't even do the low-contrast-volume scan?

(2) What is the percent chance of contrast induced nephropathy, and how reversible is it?

And is there a paper or protocol you can link to that I can show my radiology colleagues?

(By the way, this was not intended as a knock on radiologists. I just work at a place where the average age of attendings is like 80 years old, so they are not exactly up to date on stuff.)

 

[Zebra Hunter]

Contrast induced nephropathy is a mythical entity based on the logical fallacy post hoc ergo propter hoc. The evidence for contrast induced nephropathy is terrible.

http://pubs.rsna.org/doi/full/10.1148/radiol.12121823

 

[gman33]

In residency we used to get tons of pushback on scans. It was pretty crazy.

On the rare occasion when I really needed something and they wouldn't do it, I would request a bedside consult with a written note on the chart documenting the reason for refusal.

Magically those patients would be in the ct scanner about 5 minutes later.

I try to have a good relationship with my consultants and i greatly respect radiology, but sometimes they just don't see things from our perspective. Most of the data on cin is pure bs. My feeling is that on some patients I just need the study no matter what, and if I consent the patient the study should be performed.

 

[deleted77919]

…

 

[goodoldalky]

As an aside, I would consider CT surgery for a pulmonary embolectomy in a pregnant patient with a massive PE. IR for mechanical or catheter directed therapy is another option better than systemic tPA. This will depend on your CTS group but they will do them here.

 

[Zebra Hunter]

Another issue to consider in VQ vs CTA is the contrast ends up in the amniotic fluid for weeks and the risks of that contrast are not well understood.

Having said that I usually go with d-dimer, DVT study (except at night as we don't have vasc us at night at our tertiary academic center, sigh...), and proceed to CT if necessary. I always include the patients ob in the discussion. I have never had them say anything other than "If you are worried about PE go ahead with the CT."

I also don't use trimester adjusted d-dimers. If there was a study, or anything beyond expert opinion I'd really like to. However I think you are asking for trouble by trying to talk your way out of a positive d-dimer. I feel the same way about the elderly and age adjusting d-dimers.

"So doctor why did you ignore this patients positive d-dimer? Did you not see the red exclamation point next to it?"

Wait, what?

Iohexol is pregnancy category B. What about it is not well understood that you could not say about a million other drugs we give to pregnant patients without a second thought?

 

[deleted77919]

…

 

[Zebra Hunter]

I would argue that we do give second thought to just about everything we give to pregnant patients.

The last EM Rap on PE in pregnancy mentioned IV contrast from CT PE protocol ending up in amniotic fluid for weeks and not really understanding the associated risks. Can't say I've done my own research on the topic (I imagine someone somewhere has tried to measure contrast levels in pig amniotic fluid). Also hasn't changed my practice (I am more concerned over the higher radiation dose and the chance of a non diagnostic study). But it is something I hadn't considered until it was brought up in that podcast.

Sounds like fear from ignorance (speaking about the EM:rap segment). Iohexol is an incredibly inert substance. So what if it's still slightly present in the amniotic fluid for weeks? Animal models using over 100x the recommended dose for humans have shown absolutely no teratogenic effects. I think their fears are significantly overblown.

 

[gro2001]

So I saw this patient today and am having second thoughts (too late I know but nonetheless) and would love to hear what others are doing.

Youngish female, second trimester, short of breath x 2 days, worse lying flat, better on side. Reports feeling chest congestion, dry cough. No frank chest pain but feels tight. No runny nose, sore throat, yaddy yaddy. No leg swelling, calf pain. no fevers.

Exam noted for wheezing in lower lung base. Otherwise clear. No evidence of volume overload anywhere or calf tenderness. Vitals normal aside from an isolated HR on EKG to 103 (grr). Otherwise EKG fine. CXR clear. I swabbed her with respiratory viral panel looking for flu. No baby complaints. Gets albuterol. Feels better from the dyspnea standpoint/patchy wheezing gone. Wants to go home. Talk about getting CTA for PE, but decide with patient against it as she's feeling better. Return precautions, fu discussed. Then of course diagnose a PE later in the day with evidence of right heart strain in a post-op patient with pretty much the same symptoms and vitals and exam except having the post op part.

Do you just scan these ladies with SOB in pregnancy? Do you have a more nuanced approach since there's no clear decision rule and elevated d dimer thresholds while cool aren't really validated? Do you VQ them for the risk of radiation in mom's breast tissue? Do you say f-it and have a beer instead of replaying it on a Friday night?

It sounds like you considered the possibility of PE but did not think it was likely. You offered the patient the definitive study, which she declined. This sounds perfectly reasonable.

However, as with many things, the devil is in the nuance. There are many different ways to offer the same thing depending on your level of concern. For me, few things make me more concerned than legit vital sign abnormalities. If the patient was tachy to 103 (or there abouts) for some time, I would make it clear that I think she should get the CTA. I realize that heart rate increases in pregnancy. But we can probably only attribute 10-20 BPM increase to the pregnancy, yet I see many people blowing off tachycardia in the 100-110 range. If the patient is young and looks otherwise super healthy and I would expect their non pregnant heart rate to be in the 60-70 BPM range, then HR >100 is significantly tachycardic for them. If they are kinda overweight, don't exercise, used to smoke, etc, then I am less worried.

 

[Groove]

Good posts. As others have said I consider VQ pretty worthless though I still order them on occasion. The best study is only going to lower your risk to ~20%