Allan Platt, PA-C, MMSc, on Diagnosing Anemia
In this podcast, Allan Platt, PA-C, MMSC, discusses how to identify and diagnose anemia in a primary care setting, a topic he presented at the 2021 American Academy of Physician Assistants conference.
- Platt A. Anemia: too low, no go. Talk presented at: American Academy of Physician Assistants; May 20-26, 2021; Virtual. https://ww3.aievolution.com/aap2101/index.cfm?do=ev.viewEV&ev=1009
- Platt A. Emory PA/MP board review- hematology 5%. Emory Review. Accessed April 20, 2021. https://emoryreview.thinkific.com/courses/emory-pa-np-board-review-hematology
Allan Platt, PA-C, MMSC, is an assistant professor of medicine and director of admissions for the physician assistant program at Emory University in Atlanta, Georgia.
Leigh Precopio: Hello everyone, and welcome to another installment of Podcasts360, your go‑to resource for medical news and clinical updates. I'm your moderator Leigh Precopio, with Consultant360 Specialty Network.
According to the National Heart, Lung, and Blood Institute, anemia is the most common blood condition in the United States. Knowledge about common presentations and laboratory tests are essential to properly diagnosing anemia.
To discuss the diagnosis and management of anemia, I am joined by Allan Platt, PA-C, MMSc, who is an assistant professor of medicine in the physician assistant program at Emory University in Atlanta, Georgia, and a presenter on this topic at the 2021 American Academy Physician Assistants conference.
Thank you for joining me today, Allan. To begin, could you give us a brief overview of your session?
Allan Platt: My session is how to work up and diagnose all the types of anemia that you will encounter in primary care. A lot of people are confused and don't know quite how to approach it. I try and make it fairly simple. There's an organized, algorithmic way to do it.
If you follow the steps, you can diagnose about 90% of anemia just using some peripheral blood test and the clinical clues. You don't have to send everybody to a hematologist. You can take care of and diagnose about 90%, it’s that 10% you might need to refer. And the ultimate test here is a bone marrow biopsy. But in primary care, we don't do that. We can diagnose things with peripheral tests.
Leigh Precopio: What are some common pitfalls when it comes to identifying and diagnosing anemia in primary care? How can these pitfalls be avoided?
Allan Platt: Some of the common pitfalls I've seen in practice is, it is a laboratory diagnosis based on the complete blood count or CBC. That's one of the world's most common blood test we do every day in primary care because it gives us the counts of red cells, white cells, and platelets and then some other data.
What I see as a common mistake is people who suspect anemia don't get a reticulocyte count. That is indicating how is your bone marrow responding to the anemia. The reticulocyte count should be high if your marrow is working. If it's low, it isn't working. It's a very simple test. People don't order it because it's separate from the CBC, but it's your best indicator of how your bone marrow is doing. Your bone marrow is the factory of all those cells. It helps you differentiate am I dealing with a bone marrow problem, or am I dealing with red cell loss? That means bleeding or breaking up cause hemolysis.
The first test I want to know when you say somebody's anemic, I say, "What's their retic count?" A lot of people don't get it. They order it three days later, four days later. When you think anemia, always think CBC retic. Add the retic, always. It is not a part of the CBC, you got to ask for it separate.
Another thing I see in the initial workup is people don't get a red cell morphology. That means a human eyeball looks at a smear of the blood cells. Back in the day when we didn't have all these automated machines, a clinician, would actually make a blood smear and look at the red cells. You can make diagnosis right off of that. We have to ask our laboratory to do that. Never forget that, some great clues come by a human eyeball it strains looking at the red cells, so that's part of your workup.
The other part of the workup I say is, make sure you get a metabolic profile so you can see what the kidneys are doing. They're essential for making red cells. You think your kidney just makes urine. No it doesn't, it senses your oxygen level. It has a hormone called erythropoietin that tells the bone marrow to make more red cells when you get low in oxygen down in your kidney. Kidney failure is a big cause of anemia. We want to see how is your kidney, how is your liver doing? Both those are essential for good red cell production.
The last thing we usually get in our workup as a urinalysis. It's very simple, very cheap, but it does tell us how your kidneys are doing. Again, the kidneys play a big role in the genesis of red cells. Never forget that.
Taking a good careful history is important because there's clues. One of them is a forgotten question. It's called PICA, P‑I‑C‑A. You have to ask your patient, "Are you eating things that aren't normally on the diet?" You turn to the significant other or the parents and say, "Are they eating things that aren't in your diet? Like clay, starch, crunching ice all the time?" That's PICA. It's a great clue for iron deficiency. You got to ask it, because people don't usually volunteer that they're eating foam rubber all day. You got to ask that, they could be sly about it.
The other thing is to always ask about, "Have you had bariatric surgery?" Now that cures diabetes, it makes people lose a lot of weight. It also eliminates all your absorption capability for iron and B12. Guess what happens after your bariatric surgery three years down the road? You become an anemic because you can't absorb the nutrients. That may be a big cause, you always want to see what's happened in your gut. Have they bypassed things that should be there? Big thing about surgery, you got to check what happened before.
Another pitfall is the most common reason people get anemic is bleeding from their gut. They don't know it. The most common place to lose blood is from the GI tract. Always ask your patient, "What kind of pain medicine do you use?" I never say, "Do you use aspirin and all those?" They'll say, "No, I never touch that." But all the pain remedies have aspirin. Well, aspirin basically kills your platelets dead. Platelets are your clotters. They make a hole in your tummy. Now you're bleeding, but you feel good. I don't feel pain. You bleed, bleed, bleed. All the non‑steroidal anti‑inflammatory pain medicines do that. They make holes in the tummy. You don't feel pain, and the platelets don't work. Always ask about that as a cause for anemia from GI bleeding. That's a common mis fall, I would say. Those are some of the commonest things I've seen.
Leigh Precopio: How has the COVID-19 pandemic and shifted telehealth impacted primary care providers diagnosis and management of anemia?
Allan Platt: Anemia is a lab diagnosis. You have to get the patient to get a blood draw somewhere. You can't make a full diagnosis without getting your blood chemistries, and the red cell counts, and CBC, and all those things. It is a laboratory diagnosis. A lot of people may not go diagnosed because they're not getting the proper lab work done.
You can do some things over Zoom, and we do Telehealth over Zoom. You can actually look and do general inspection with your patient and pick up a lot of clues. The most valuable thing I have is have the patient lean into the camera, pull their lower lid down, and look up. If your conjunctiva is nice and red, you're not anemic, you're fine. If it's pale and washed out, that's a great sign you're anemic. In two seconds, I can tell you're anemic if you give me a good camera shot.
The other thing I'm looking at is the white of your eye, the sclera. If it's yellow, you're jaundiced. One of the things that makes you anemic is hemolysis. That can make you jaundice, when the red cell burst apart you release bilirubin, it's called indirect bilirubin, into the bloodstream. It will make you yellow. Until it gets to the liver, it is indirect bilirubin. Then it's converted to direct bilirubin, which is what you use to digest your cheeseburger. That's a great clue for diagnosing hemolysis, is jaundice. When you get the chemistries, it's indirect bilirubin is elevated. You can see that by just a quick eyeball look at your patient. Those are some clues you can do on telemedicine.
The other thing is by history. If you ask them, are they tired? Are they feeling short of breath? All those things. Weak and dizzy as we call it. Those are all signs of anemia. They may have cold extremities. The other thing they may have is kind of numbness and tingling in their hands and feet. Great sign for B12 deficiency that gives you neurologic signs, so does lead poisoning. Lead poisoning can cause anemia and it gives you those neurologic symptoms.
Things you can do by telemedicine, you can still do a great history because we're talking. You can do some physical exam, basically check the eyes. That's a great clue. You can look around the lips and the mouth for glossitis and cheilosis and those are signs of B12 deficiency.
A good look at the patient over a camera can give you some great clues. Ultimately, you got to get blood. Got to get a needle in the arm and get some blood out.
Leigh Precopio: What are some clinical pearls that you give for differentiating between the types of anemia when using common tests such as a complete blood count?
Allan Platt: Yes, I like the complete blood count but also a retic count. Always say those two words together, because the retic count puts the anemia in two different buckets. I like thinking of diagnosing anemia in buckets.
First two buckets are, is your bone marrow working? Then your retic count should be high when you're anemic. If that's the case, you're losing blood by bleeding or hemolysis. The other things - we will work that up in a minute. If the marrow is low, it's not working. If the reticulocyte count is not what it should be, you have to look at the cell size. The red cells are either too big, too small or just right, like Goldilocks and the Three Bears. And then you can do specific test to make the diagnosis in each of those categories.
Those are the three buckets I tell people to look at next. First thing is the retic count is low, then I want to know what is my cell size? Which comes back on your complete blood count. How big are their cells? If they're small, it's called microcytic anemia. Four things they have to diagnose every time. The most common in the world is iron deficiency. So you got to do iron studies. Mainly ferritin, is which you get in the storehouse. The other one is inflammatory block. Inflammation is a big cause of anemia. There's a test called the C‑reactive protein that says, "Is my body inflamed?"
Other ones to think about is sideral blastic, which causes from lead poisoning. A lot of that's going around in the country from lead pipes. That can give you a microcytic anemia. Also, thalassemia. Thalassemia is the genetic cause of microcytic anemia that you're born with.
A lot of people walking around that have, looks like iron deficiency, but they're this way all their life and they're not in trouble. They can have no symptoms at all. Those people don't need iron therapy at all. In fact, it could be dangerous for them. You have to think of those four things when you have microcytic anemia and that's the most common.
For normocytic anemia, it could be mainly renal failure or chronic inflammation are the most common. Then when it's too big, the cells are really big, think of B12 and folate and you'd run those tests. You can be very targeted based on the cell size of the next test to order to make your diagnosis.
For hemolysis, whole other side, you have to have a high indirect bilirubin, high LDH. Then you have to say why are my red cells breaking apart? You got to think that hereditary like sickle cell disease or thalassemia. Could it also be an enzyme problem? G6PD is a very common deficiency and usually it happens after we clinicians give drugs, like sulfa drugs, like bactrim, and septra for infection. If somebody's walking around with G6PD, inherited that genetic trait, they will hemolyze with that drug. They will come in jaundice and dropping their blood count, but their infections going away. Very common scenario, you stop the drug and make sure the patient is switched something else and educate them.
Then there's autoimmune things, the body can attack red cells. That gets involved in that may need a hematologist referral. Red cells can be attacked by your own immune system. We see this in COVID and a few other things. It's rare, but it can happen where the body turns on its own red cells. That's a whole other workup. That's when primary care should punt to the hematologist. You need help.
Leigh Precopio: What are the overall key take‑home messages from your session? How can they be implemented into clinical practice?
Allan Platt: One, being a thoughtful clinician and always get that retic count when you order your CBC. Think of the differentials based on, is it a low retic count versus a high retic count? If it's low, look at your cell size and again, the microcytic is going to be your most common anemia you encounter in primary care. So think of the four differentials.
The pneumonic I like is tics. T‑I‑C‑S, not the blood sucking critter. It's like a tic, facial tic. Think of TICS, thalassemia, iron deficiency, chronic inflammation and sideral blastic, which equals lead. If you always run through that you'll never go wrong. You'll always catch and make the right diagnosis.
The other caveat with iron deficiency is find out why. The person may have colon cancer if they're the right age and they're having a slow bleed over time. Always pursue, why is this person low in iron? It could be diet, it could be menses in a female. You always got to ask, why is this person low? Make sure you get the root cause, because we can give you iron back. That's OK. Always find out if it's a leaking problem.
Chronic inflammation, you can't do anything about that until you fix the inflammation. If you got rheumatoid arthritis, HIV, any of those things. If you calm that down the anemia corrects, so you got to work on the disease.
Lead, you can get the lead out. We have medicines to do that. You want to diagnose it because it can cause mental retardation in kids, and neurologic problems that can be permanent. You don't want to miss lead poisoning. That's the most common encounter primary care is going to see.
The next most common would be the big red cell size, and that's B12 and folate. Always correctable and fixable. You don't want to miss those because B12 can cause a reversible dementia. It can cause neurologic damage. Again, you want to find it and fix it.
Those are the main pearls that I could think of that I would like to bestow on the world. Keep looking, always say "Why?" Why is this person? Keep pursuing it to get a diagnosis. Anemia is not a diagnosis, it's a sign. You got to keep digging down until you get the correct reason for them being anemic and make the final diagnosis and then you can treat it appropriately.
Leigh Precopio: Great. Thank you for taking the time to speak with me today.
Allan Platt: I enjoyed it. Thank you for having me.