Approach to the Anemic Patient I and II

Question 1

Anemia is reduced oxygen carrying capacity from insufficient _________ and ____________ within the vasculature

Answer 1

Anemia is reduced oxygen carrying capacity from insufficient hemoglobin and RBC mass within the vasculature

Question 2

What are the 3 general/broad differentials for anemia?

Answer 2

1. LOSS (induced vs spontaneous)
2. DESTRUCTION (infectious, immune-mediated, drug-induced, or mechanical/ DIC)
3. HYPOPLASIA (refractory or bone marrow issue)

Question 3

What are components of a patients history that may make you suspect anemia is occuring?

Answer 3

• weakness, lethargy, collapse
• pale gums
• jaundice/icterus
• recent trauma (esp blunt)
• melena or hematochezia
• obvious blood loss
• breathing changes
• distended abdomen

Question 4

What are physical exam findings that would make you suspect anemia?

Answer 4

• pale MM
• tachycardia
• heart murmur
• bounding or weak pulses
• dullness, weakness, collapse
• icterus
• bruising, ecchymoses/petechiae
• pleural or abdominal effusion
• obvious bleeding

Question 5

T/F: the body can adapt to anemia if it is given the time to adjust

Answer 5

true

this is why a patient can have an extremely low PCV and TS, and can have a relatively normal patient compared to another patient with an acute drop in hemoglobin/RBCs that is showing severe clinical signs.

Those with chronic anemia and are compensating are more likely to have anemia as a result of lack of production or destruction as opposed to loss.

Question 6

How can you confirm anemia if you are suspicious of it based on history and physical exam findings?

Answer 6

• PCV AND Total Solids
• CBC (Hct, reticulocytes) + blood smear

Question 7

How is it possible for a patient to be anemic with a normal PCV or Hct?

Answer 7

PCV and Hct measure the % of the blood that is RBCs. If blood loss has occurred rapidly, you initial PCV or Hct readings will likely be normal because the patient has lost RBCs and plasma. Once the water gets redistributed from other areas of the body (or you administer fluids), the PCV will go down (redistribution).

Question 8

What would you expect the PCV and TS to be in a case of blood loss anemia?

Answer 8

early on:
normal PCV, slight increase/normal TS

Later on:
DECREASED PCV
DECREASED TS

Question 9

what would you expect your PCV and TS to be in a case of anemia caused by destruction (ex. IMHA)?

Answer 9

DECREASED PCV
increased/normal TS
Serum may be yellow

Question 10

what would you expect the PCV/TS to be in a case of anemia caused by lack of production (ex. aplastic anemia)?

Answer 10

DECREASED PCV
normal/increased TS

Question 11

What would you expect to see on a CBC for a patient with anemia caused by blood loss?

Answer 11

1. Increased reticulocytes (d/t regeneration; unless pre-regenerative, then the reticulocytes will be low/normal)
2. polychromasia (macrocytic, hypochromic, some nucleated RBCs)

Question 12

What type of CBC changes would you expect to see in a case of anemia caused by destruction?

Answer 12

• INCREASED reticulocytes (d/t regeneration)
• polychromasia (macrocytic, hypochromic)
• if IMHA – spherocytes
• inflammatory leukogram

Question 13

what would you expect to see on a CBC of a patient with anemia due to lack of production?

Answer 13

• pancytopenia (if bone marrow is the problem)
• NON-regenerative anemia (reticulocytes will be low)
• Normocytic, normochromic (bc only old RBCs are left)

Question 14

What are the 3 big causes of acute blood loss anemia?

Answer 14

1. trauma
2. coagulopathy
3. cancer

Question 15

what are the 3 big causes of chronic blood loss anemia?

Answer 15

1. parasites
2. ulcers
3. cancer

Question 16

what are the 4 causes of anemia caused by destruction (hemolytic anemia)? which is most common

Answer 16

1. immune-mediated*
2. infectious
3. drug/toxin-induced oxidative damage
4. mechanical (DIC)

Question 17

What are the causes of refractory hypoplastic anemia (lack of production)?

Answer 17

1. anemia of chronic disease/inflammation
2. renal failure (erythropoietin production)
3. iron deficiency (chronic blood loss or dietary deficiency)

Question 18

what are the various bone marrow disorders that lead to hypoplastic anemia?

Answer 18

1. aplastic anemia
2. drug-induced
3. cancer
4. immune-mediated
5. idiopathic
6. infectious

Question 19

What type of anemia will zinc toxicity lead to?

Answer 19

hemolytic anemia!

zinc toxicity looks a lot like IMHA (regenerative anemia – reticulocytosis, nucleated RBCs, polychromasia, inflammatory leukogram; hyperbilirubinemia - icterus; and some may have spherocytosis.)

Question 20

what is the prognosis for zinc toxicity induced hemolytic anemia?

Answer 20

good to excellent.

Question 21

Describe how to perform macroagglutination test

Answer 21

1 drop of anti-coagulated blood + 1 drop of saline onto a slide and observe for macroagglutination (bad = IMHA)
you can also look for microagglutination using the microscope.

Question 22

Once you have performed a CBC/Chem and macroagglutination test and decided that your patient likely has IMHA. What is the next step?

Answer 22

You must decipher between primary IMHA or secondary IMHA.

You should do this by performing infectious disease testing (babesia, FeLV, mycoplasma, etc.)
And you should screen your patient for cancer (thoracic and abdominal imaging)

Question 23

You have diagnosed your patient with primary IMHA. How do you treat this patient?

Answer 23

1. Prednisone BID (or you can start pred then start azathioprine) continue until PCV stabilizes, hyperbilirubinemia resolves (min 1 month), if in remission decrease dose by 25% then reassess 2 weeks later; repeat 25% reduction every 2 weeks if still in remission
2. Anti-platelet drugs (clopidogrel, aspirin) and/or anti-coagulant drugs (unfractionated heparin, low MW heparin, oral rivaroxaban) continue until completely weaned off pred, then slowly wean over 2-3 weeks.
3. blood transfusions as needed to increased oxygen carrying capacity.

Question 24

what are the 2 most common causes of death in IMHA cases?

Answer 24

1. thromboembolism
2. not enough $$ for transfusions

Question 25

If you have a patient that is showing signs of hypovolemic shock and their PCV/TS are both low, what can you interpret from these findings?

Answer 25

blood loss anemia

Question 26

What would be an ideal diagnostic test to run on a patient with blood loss anemia?

Answer 26

PT and PTT

if both are prolonged, this supports spontaneous hemorrhage.

Question 27

What is the purpose of giving a patient with blood loss anemia fresh frozen plasma or whole blood products?

Answer 27

they need to replenish their clotting factors in order to stop bleeding further.

Question 28

what is the purpose of giving fluids (LRS or Normosol-R) to a patient with blood loss anemia?

Answer 28

to treat the hypovolemic shock

Question 29

If you’ve given your patient that has blood loss anemia fluids and fresh frozen plasma and there was minimal to no improvement to the patients HR, temp, or mentation, what should you do next?

Answer 29

give packed red blood cells (this helps increase oxygen carrying capacity to improve perfusion)

Question 30

If a dog presents to your clinic with no signs of shock on presentation, but CBC shows SEVERE anemia (microcytic, hypochromic, inappropriate regeneration, normal plasma), what does this tell you about the anemia itself?

Answer 30

its chronic because the dog looks ok on presentation. And, in this case, since there is an Fe deficiency (microcytic hypochromic), we can assume that the blood loss is external (respiratory, GI*, or urogenital).

Question 31

Of the 3 sources of chronic, external blood loss (respiratory, GI, urogenital), what are 3 common etiologies for GI blood loss?

Answer 31

1. parasitism
2. ulceration
3. neoplasia

Question 32

A cat presents to your clinic BAR, but white MM and unobtainable CRT. On CBC, this cat has a severe chronic non-regenerative anemia. What is the most common cause – loss, destruction, or lack of production?

Answer 32

lack of production

(supported by non-regenerative nature)

Question 33

Once you’ve determined that your patient has severe chronic anemia from a lack of production, you need to distinguish between a primary bone marrow cause or refractory anemia.
How would you do this?

Answer 33

1. FeLV/FIV test
2. Bone marrow aspirate or biopsy