Approach to the Anemic Patient I and II Flashcards
Anemia is reduced oxygen carrying capacity from insufficient _________ and ____________ within the vasculature
Anemia is reduced oxygen carrying capacity from insufficient hemoglobin and RBC mass within the vasculature
What are the 3 general/broad differentials for anemia?
- LOSS (induced vs spontaneous)
- DESTRUCTION (infectious, immune-mediated, drug-induced, or mechanical/ DIC)
- HYPOPLASIA (refractory or bone marrow issue)
What are components of a patients history that may make you suspect anemia is occuring?
- weakness, lethargy, collapse
- pale gums
- jaundice/icterus
- recent trauma (esp blunt)
- melena or hematochezia
- obvious blood loss
- breathing changes
- distended abdomen
What are physical exam findings that would make you suspect anemia?
- pale MM
- tachycardia
- heart murmur
- bounding or weak pulses
- dullness, weakness, collapse
- icterus
- bruising, ecchymoses/petechiae
- pleural or abdominal effusion
- obvious bleeding
T/F: the body can adapt to anemia if it is given the time to adjust
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.
How can you confirm anemia if you are suspicious of it based on history and physical exam findings?
- PCV AND Total Solids
- CBC (Hct, reticulocytes) + blood smear
How is it possible for a patient to be anemic with a normal PCV or Hct?
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).
What would you expect the PCV and TS to be in a case of blood loss anemia?
early on:
normal PCV, slight increase/normal TS
Later on:
DECREASED PCV
DECREASED TS
what would you expect your PCV and TS to be in a case of anemia caused by destruction (ex. IMHA)?
DECREASED PCV
increased/normal TS
Serum may be yellow
what would you expect the PCV/TS to be in a case of anemia caused by lack of production (ex. aplastic anemia)?
DECREASED PCV
normal/increased TS
What would you expect to see on a CBC for a patient with anemia caused by blood loss?
- Increased reticulocytes (d/t regeneration; unless pre-regenerative, then the reticulocytes will be low/normal)
- polychromasia (macrocytic, hypochromic, some nucleated RBCs)
What type of CBC changes would you expect to see in a case of anemia caused by destruction?
- INCREASED reticulocytes (d/t regeneration)
- polychromasia (macrocytic, hypochromic)
- if IMHA – spherocytes
- inflammatory leukogram
what would you expect to see on a CBC of a patient with anemia due to lack of production?
- pancytopenia (if bone marrow is the problem)
- NON-regenerative anemia (reticulocytes will be low)
- Normocytic, normochromic (bc only old RBCs are left)
What are the 3 big causes of acute blood loss anemia?
- trauma
- coagulopathy
- cancer
what are the 3 big causes of chronic blood loss anemia?
- parasites
- ulcers
- cancer
what are the 4 causes of anemia caused by destruction (hemolytic anemia)? which is most common
- immune-mediated*
- infectious
- drug/toxin-induced oxidative damage
- mechanical (DIC)
What are the causes of refractory hypoplastic anemia (lack of production)?
- anemia of chronic disease/inflammation
- renal failure (erythropoietin production)
- iron deficiency (chronic blood loss or dietary deficiency)
what are the various bone marrow disorders that lead to hypoplastic anemia?
- aplastic anemia
- drug-induced
- cancer
- immune-mediated
- idiopathic
- infectious
What type of anemia will zinc toxicity lead to?
hemolytic anemia!
zinc toxicity looks a lot like IMHA (regenerative anemia – reticulocytosis, nucleated RBCs, polychromasia, inflammatory leukogram; hyperbilirubinemia - icterus; and some may have spherocytosis.)
what is the prognosis for zinc toxicity induced hemolytic anemia?
good to excellent.
Describe how to perform macroagglutination test
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.
Once you have performed a CBC/Chem and macroagglutination test and decided that your patient likely has IMHA. What is the next step?
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)
You have diagnosed your patient with primary IMHA. How do you treat this patient?
- 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
- 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.
- blood transfusions as needed to increased oxygen carrying capacity.
what are the 2 most common causes of death in IMHA cases?
- thromboembolism
- not enough $$ for transfusions
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?
blood loss anemia
What would be an ideal diagnostic test to run on a patient with blood loss anemia?
PT and PTT
if both are prolonged, this supports spontaneous hemorrhage.
What is the purpose of giving a patient with blood loss anemia fresh frozen plasma or whole blood products?
they need to replenish their clotting factors in order to stop bleeding further.
what is the purpose of giving fluids (LRS or Normosol-R) to a patient with blood loss anemia?
to treat the hypovolemic shock
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?
give packed red blood cells (this helps increase oxygen carrying capacity to improve perfusion)
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?
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).
Of the 3 sources of chronic, external blood loss (respiratory, GI, urogenital), what are 3 common etiologies for GI blood loss?
- parasitism
- ulceration
- neoplasia
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?
lack of production
(supported by non-regenerative nature)
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?
- FeLV/FIV test
- Bone marrow aspirate or biopsy
