Low iron level with normal CBC

Melody007_FNP-C, APRN · Jul 31, 2015

She could be dehydrated...that would give a false higher hgb. At age 87 dehydration is common. I had a pt who HGB was 8.9, Iron 29, TIBC 422,..total iron sat 7.3%, with SOB, chest palpations, extreme fatigue, etc. Seemed odd at 8.9 to have that extreme of symptoms. CMP showed BUN/Creatine ratio at 34. Patient dehydrated....long story short after receiving one unit of whole blood the HGB was 8.4. So the 8.9 was false high. Pt now on Nifrex bid.

HTH,

Melody ARNP Student

edmia, BSN, RN · Jul 31, 2015

You'd need to draw a ferritin level and total iron binding capacity to really assess the iron status. The hemoglobin and hematocrit could be normal and the ferritin stores be almost gone. This is an early IDA state and the patient could show fatigue and exercise intolerance.

Also, get a stool sample for occult blood to start figuring out why the iron is low.

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CocoaLoverFNP · Jul 31, 2015

Hi all. I have a patient who's total Iron was in low range (37) but CBC normal. I did not order TIBC or Ferritin. Patient has reported increasing fatigue with shortness of breathe. Would you go ahead and treat it with iron supplementation or should I follow up with ferritin and TIBC? Pt is 87 years old who does not eat well so I'm suspecting it's due to poor diet status.

I would most likely order a serum ferritin and TIBC first before prescribing iron. Knowing that these values support my ddx of IDA would help me sleep better at night.

For this elderly patient, i would also be worried about a slow GI bleeding process so i will prdee guaiac stool for this.

I will assume that the work-up to r/o other diseases for his c/o fatigue with SOB has already been done. But if not, i would be curious to find out when was the last/what was the result of his last echo, electrolyte levels, thyroid panel, B12 level, and Vit D. How about depression/anxiety?

Trauma Columnist · Jul 31, 2015

Also, as renal function normally decreases with age, checking a renal function panel along with above-mentioned labs would be in order.

I too vote for the dehydration diagnosis too.

dimama, MSN, APRN · Aug 1, 2015

You'd need to draw a ferritin level and total iron binding capacity to really assess the iron status. The hemoglobin and hematocrit could be normal and the ferritin stores be almost gone. This is an early IDA state and the patient could show fatigue and exercise intolerance.
Also, get a stool sample for occult blood to start figuring out why the iron is low.
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Agree completely. This is how I would proceed with this patient as well.

chouxpastry · Aug 1, 2015

If CBC is normal, I would generally not pursue additional testing to prove iron deficiency or GI blood loss. However, if a correlating BMP/Chem-7 demonstrates acute on chronic renal insufficiency along with hemoconcentration, then I would attempt re-hydration versus further testing. Serum iron is very fluctuant and thus unreliable. In general, an iron panel is a more comprehensive diagnostic indicator of iron deficiency. Occult fecal testing may be positive if patient has mildly symptomatic hemorrhoidal/local bleeding. Do you have other lab values on this patient? I would consider r/o cardiac, pulmonary, malignancy etx in light of patient's goals of care at 87 years.

reddgirl · Aug 4, 2015

Yep, draw the rest of the iron study panel and always look to the GI tract first in elderly people. I saw a lot of that in Geriatrics. Draw a Chem panel too to look at your kidneys as well.

NurseNeLz · Feb 25, 2016

Thank you for all the suggestions!