Microcytic anemia

[seminoma]

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In a 30s female with regular menstruation and mild dyspnea on exertion is the first step to test for serum iron/ferritin or would you just do a trial of iron therapy?

Hb is 11, MCV 73.

 

[J ROD]

take that **** to trial!

 

[H Y F R]

In a 30s female with regular menstruation and mild dyspnea on exertion is the first step to test for serum iron/ferritin or would you just do a trial of iron therapy?

Hb is 11, MCV 73.

She is symptomatic. And you can throw iron at something like a thalassemia, which would not correct with iron. First step is CBC. Now that you have that, the next step is an iron profile to diagnose. Giving iron without the thorough work up is possible here, but she is symptomatic, so I thin proper diagnosis would be my gut feeling. But I could be wrong...

 

[J ROD]

I swear I ran across a question somewhere that asked something similar and it said since the patient had symptoms to go ahead and treat. And, then if there is no response look for other causes.

In practice, I would run a CBC and iron studies and go ahead and start treatment with Fe since there are no real major risks. Except GI upset and constipation. Then, go from there. I hate these damn tests! 😡

 

[Phloston]

If the picture is clearly a microcytic anaemia then iron deficiency is likely the cause. To be completely honest I'd say the next best step is asking her if she eats ice or clay and check her palms, eyes and nails, and ask if she has issues swallowing (webs). If iron doesn't work then additional workup is appropriate for less common causes, although I don't see any reason why that workup couldn't be done simultaneously.

 

[Instatewaiter]

She is symptomatic. And you can throw iron at something like a thalassemia, which would not correct with iron. First step is CBC. Now that you have that, the next step is an iron profile to diagnose. Giving iron without the thorough work up is possible here, but she is symptomatic, so I thin proper diagnosis would be my gut feeling. But I could be wrong...

1) You have a hemoglobin and an MCV... sounds like somone already ordered a CBC, you know, since no one ever orders an MCV by iteslf...

2) Symptomatic with a hemoglobin of 11... what planet are we on?

 

[animando]

2) Symptomatic with a hemoglobin of 11... what planet are we on?

-> USMLE

i'd order a ferritin level first to confirm dx ; also to calculate total iron deficit.

 

[H Y F R]

1) You have a hemoglobin and an MCV... sounds like somone already ordered a CBC, you know, since no one ever orders an MCV by iteslf...

2) Symptomatic with a hemoglobin of 11... what planet are we on?

1) Already noted when I wrote the statement. Cheers on pointing it out to me. Be less condescending and assuming.

2) Symptomatic is symptomatic. It could be anemia, could be X, Y, Z. That's why we have reasoning, thought, and discourse to work through as colleagues. Cheers for having no diagnostic curiosity.

 

[cbrons]

In a 30s female with regular menstruation and mild dyspnea on exertion is the first step to test for serum iron/ferritin or would you just do a trial of iron therapy?

Hb is 11, MCV 73.

Hb of 11 is barely below normal for the average female. They would most likely be asymptomatic unless there are other compounding factors at play.

Also microcytic anemia is not "by definition" IDA.
Anemia of chronic disease can be microcytic (usually not though). And then you have those rarer things like thalessemias, lead poisoning, sideroblastic anemia etc.

Of course in a 30s female it would be IDA 99% of the time unless they are black, south asian, or in that Mediterranean group that gets beta thalassemia.

I think the question is stupid if a.) the only thing it says is what is listed in the OP and b.) the only answer choices revolve around treatment for IDA or iron studies. I would think an otherwise health 30 year old female with dyspnea on exertion requires more of a workup than just iron pills or iron studies.

 

[Apoplexy__]

In a 30s female with regular menstruation and mild dyspnea on exertion is the first step to test for serum iron/ferritin or would you just do a trial of iron therapy?

Hb is 11, MCV 73.

This is a really tricky concept and UWorld makes a very defined stance on it once you go through all the IM and Peds Q's. I recall with certainty that in the pediatric population, you do empiric therapy -- the likelihood of it being anything other than iron deficiency is extremely low.

In this patient, I would elect to do more studies, though. We don't know that this is symptomatic anemia; we only know that she's symptomatic and anemic. DOE in this patient population deserves a thorough workup. I believe UWorld also supports this, in saying that you generally confirm iron deficiency before treating in adults.

 

[seminoma]

Hb of 11 is barely below normal for the average female. They would most likely be asymptomatic unless there are other compounding factors at play.

Also microcytic anemia is not "by definition" IDA.
Anemia of chronic disease can be microcytic (usually not though). And then you have those rarer things like thalessemias, lead poisoning, sideroblastic anemia etc.

Of course in a 30s female it would be IDA 99% of the time unless they are black, south asian, or in that Mediterranean group that gets beta thalassemia.

I think the question is stupid if a.) the only thing it says is what is listed in the OP and b.) the only answer choices revolve around treatment for IDA or iron studies. I would think an otherwise health 30 year old female with dyspnea on exertion requires more of a workup than just iron pills or iron studies.

OP is similar to a question on the medicine shelf. No other relevant info was provided.

 

[Instatewaiter]

1) Already noted when I wrote the statement. Cheers on pointing it out to me. Be less condescending and assuming.

2) Symptomatic is symptomatic. It could be anemia, could be X, Y, Z. That's why we have reasoning, thought, and discourse to work through as colleagues. Cheers for having no diagnostic curiosity.

1) You're welcome.

2) I do have "diagnostic curiosity" especially since I realize that this patient isn't going to be symptomatic from her anemia with a hemoglobin of 11. So my curiosity extends beyond the distractors. I would be looking for another cause of her symptoms but you know that's just me, a board certified internist.

 

[H Y F R]

This is a really tricky concept and UWorld makes a very defined stance on it once you go through all the IM and Peds Q's. I recall with certainty that in the pediatric population, you do empiric therapy -- the likelihood of it being anything other than iron deficiency is extremely low.

In this patient, I would elect to do more studies, though. We don't know that this is symptomatic anemia; we only know that she's symptomatic and anemic. DOE in this patient population deserves a thorough workup. I believe UWorld also supports this, in saying that you generally confirm iron deficiency before treating in adults.

This. Agreed.

 

[H Y F R]

1) You're welcome.

2) I do have "diagnostic curiosity" especially since I realize that this patient isn't going to be symptomatic from her anemia with a hemoglobin of 11. So my curiosity extends beyond the distractors. I would be looking for another cause of her symptoms but you know that's just me, a board certified internist.

Mazel tov doctor. This is a student thread. Be less condescending when we are growing and trying to get to the level of your board certified greatness. If you can be humble and acknowledge that, then Cheers for being accountable. If you want to continue punking students on the net, then youre a certified schmuck. Im done with this thread. If sdn wants to ban me, make sure to read the patronizing comments by our "board certified internist" as well.

 

[seminoma]

2) I do have "diagnostic curiosity" especially since I realize that this patient isn't going to be symptomatic from her anemia with a hemoglobin of 11. So my curiosity extends beyond the distractors. I would be looking for another cause of her symptoms but you know that's just me, a board certified internist.

I would also be curious and want to look for another cause, but whether or not that is part of the diagnostic algorithm (i.e. what is tested by the NBME/USMLE) is the point of uncertainty. I was not able to find any guidelines regarding symptomatic anemia at hb of 11.

 

[Instatewaiter]

This is a good time to do some teaching. So let's talk physiology and whether or not you should be symptomatic with a hemoglobin of 11:

It requires knowledge of a few things which you guys already know:
1) oxygen delivery ~ 1.34 hemoglobin x %sat x cardiac output
2) Normal hemoglobin for a woman is ~12
3) You get symptomatic when your oxygen delivery cannot keep up with your metabolic demands.
4) Average Cardiac output is about 5 L/min. With exercise it can go up 800%

So dropping your hemoglobin from 12 --> 11 is roughly an 8% decrease which only requires an increase in cardiac output of 9% to keep your O2 delivery the same. For a young woman that is like increasing your resting heart rate from 60 to 65. A young woman, even one with advanced cardiomyopathy would have well more than this in reserve. So, you need to lose much more than this to get symptomatic.

Now this does not account for the increased O2 extraction, the shift in the O2 dissociation curve or that you will also increase contractility which will increase your O2, all making you need even less increase in HR to keep up your O2 carrying capacity.

 

[colonelmustard]

It's likely the OP didn't consider that this Hb level wouldn't be symptomatic in this hypothetical case. So I think the OP is simply asking whether to treat or test in a symptomatic patient with a low Hb and low MCV.

Considering that this can be a microcytic anemia other than an iron deficiency, more information would have to be given in the vignette to delineate this from other microcytic anemias. UWorld typically gives peripheral smears or iron studies to help in this process. I agree with kirbymeister that if this additional information is not given, it would be appropriate to do further studies rather than giving iron first.

 

[H Y F R]

This is a good time to do some teaching. So let's talk physiology and whether or not you should be symptomatic with a hemoglobin of 11:

It requires knowledge of a few things which you guys already know:
1) oxygen delivery ~ 1.34 hemoglobin x %sat x cardiac output
2) Normal hemoglobin for a woman is ~12
3) You get symptomatic when your oxygen delivery cannot keep up with your metabolic demands.
4) Average Cardiac output is about 5 L/min. With exercise it can go up 800%

So dropping your hemoglobin from 12 --> 11 is roughly an 8% decrease which only requires an increase in cardiac output of 9% to keep your O2 delivery the same. For a young woman that is like increasing your resting heart rate from 60 to 65. A young woman, even one with advanced cardiomyopathy would have well more than this in reserve. So, you need to lose much more than this to get symptomatic.

Now this does not account for the increased O2 extraction, the shift in the O2 dissociation curve or that you will also increase contractility which will increase your O2, all making you need even less increase in HR to keep up your O2 carrying capacity.

Cheers doctor on the thorough and well-stated explanation. I appreciated reading it. Hope all is well with you and your patients.