Exam 3 - IMHA Diagnosis & Therapy

Question 1

which is worse: intravascular hemolytic anemia or extravascular hemolytic anemia?

Answer 1

intravascular

Question 2

what is the mechanism associated with intravascular hemolytic anemia?

Answer 2

rupture within the blood vessel – IgM associated

can happen from toxins, not just immune

hemoglobin released in blood & urine

Question 3

what is the mechanism associated with extravascular hemolytic anemia?

Answer 3

destruction of RBC by macrophages in spleen or liver – usually IgG

Question 4

what lab abnormalities are associated with intravascular hemolytic anemia?

Answer 4

hemoglobinemia, hemoglobinuria, pigmenturia, & red serum

Question 5

what lab abnormalities are associated with extravascular hemolytic anemia?

Answer 5

hyperbilirubinemia, hyperbilirubinuria, pigmenturia, & yellow serum

Question 6

what are the main differences between the causes of primary & secondary hemolytic anemia?

Answer 6

primary – synonymous with idiopathic, underlying cause not found

secondary – identifiable underlying trigger such as: antibiotics, vaccination, infectious, parasites, must rule out toxins such as zinc & penny ingestion

Question 7

what breeds are predisposed to IMHA?

Answer 7

cocker spaniels, poodles, & springers

Question 8

what patient signalment is predisposed to IMHA?

Answer 8

female spayed, young to middle aged animal

Question 9

what are 2 external factors that can predispose an animal to developing IMHA?

Answer 9

1. antibiotics with a hapten group – penicillins & cephalosporins
2. rickettsial or bacterial infections triggering immune system

Question 10

what can be seen on physical exam on a patient with IMHA?

Answer 10

pale MM, may be icteric, poor pulse quality, pigmenturia, tachypnea

Question 11

what lab abnormalities are commonly seen with IMHA?

Answer 11

severe leukocytosis with left shift, can fluctuate with MCV/MCHC, anisocytosis, macrocytosis, nRBC, +/- Heinz bodies

Question 12

what are the red & yellow arrows indicating in the serum seen on PCV?

Answer 12

red – hemoglobin
yellow – bilirubin

Question 13

what is expected of a PCV/TS in an animal with IMHA?

Answer 13

usually normal or high total solids

Question 14

what is classic of IMHA on a blood smear?

Answer 14

spherocytes – dogs
agglutination – macroscopic or microscopic, but differentiate from rouleaux

Question 15

what may be seen on a chemistry panel of a patient with IMHA?

Answer 15

variable depending on underlying problem & type of hemolysis - +/-:
increased bilirubin, hepatopathy, hyperglobulinemia, & azotemia (pre-renal or renal) often from intravascular hemolysis & subsequent AKI

Question 16

why do abdominal rads in a patient with IMHA?

Answer 16

rule out zinc toxicity

Question 17

what are some negative prognostic markers for IMHA?

Answer 17

1. intravascular hemolysis
2. presence of concurrent thrombocytopenia – evans syndrome or babesia
3. persistently non-regenerative
4. increasing number of blood transfusions
5. degree of hyperbilirubinemia
6. azotemia

Question 18

only intravascular hemolysis causes what 2 lab abnormalities?

Answer 18

hemoglobinuria & hemoglobinemia

Question 19

why is it important to rule out infectious causes for patients with intravascular hemolysis?

Answer 19

consider necessary immunosuppression

Question 20

what are some absolute ‘triggers’ for transfusing an IMHA patient?

Answer 20

PCV <12% or the animal is unstable

Question 21

why is it ideal to give an IMHA patient packed RBC instead of whole blood?

Answer 21

whole blood is more inflammatory/immunogenic

Question 22

transfusions make it difficult to assess what CBC parameters of your patient?

Answer 22

reticulocytes, RBC parameters, & agglutination

Question 23

T/F: it Is very rare for cats to have IMHA

Answer 23

true

Question 24

prior to immunosuppressing a cat with suspected IMHA, what should you do?

Answer 24

treat for mycoplasma

Question 25

what steroid therapy is used for IMHA patients initially?

Answer 25

steroids – injectable dex or dex sp at 2 mg/kg/day until patient is eating

Question 26

why use clopidogrel in a patient with IMHA?

Answer 26

anti-platelet agent because IMHA patients are prone to thromboembolisms dose 1-2 mg/kg/day

Question 27

when should you add a secondary non-steroidal immunosuppressant for an IMHA patient?

Answer 27

technically every IMHA, but especially when negative prognostic factors are present such as: intravascular hemolysis, non-regenerative anemia, & multiple blood transfusions

Question 28

what is the action & dosage used for cyclosporine?

Answer 28

inhibits normal t cell function – dose at 5 mg/kg PO twice daily

Question 29

what are the pros & cons of using cyclosporine?

Answer 29

very good immunosuppressant that can be monitored with a pharmacodynamic assay expensive & animal is most susceptible to fungal disease in certain parts of the country

Question 30

what care must be used when you put an IMHA patient on cyclosporine?

Answer 30

monitor very closely for fungal disease – wipe paws with chlorohexidine wipes every time the animal goes outside, swims, or digs in dirt ideally limit exposure to outside world while immunosuppressed

Question 31

when are IMHA patients discharged?

Answer 31

when they are eating & drinking, taking oral meds well, PCV/TS stabilizing/holding well, & no longer requiring transfusions

Question 32

what monitoring should be used for IMHA patients once they leave the hospital?

Answer 32

recheck PCV/TS, agglutination, spherocytes, or CBC – weekly until PCV reaches at least 30%

Question 33

when do you taper steroids or secondary immunosuppressants in your IMHA patients?

Answer 33

normal Hct/PCV >30% for at least 2-3 weeks taper in 25% increments every 3-4 weeks taper steroids first then secondary agent

Question 34

what should you do if you have a refractory case of IMHA?

Answer 34

look for missed trigger, ensure gi bleeding isn’t a confounding problem, & reassess for infectious disorders

Question 35

babesia in dogs is nearly identical to what two concurrent diseases?

Answer 35

concurrent IMHA & IMTP – evans’ disease

Question 36

what animals are predisposed to babesiosis?

Answer 36

splenectomized animals pitbulls & greyhounds

Question 37

how do you rule out babesia in dogs?

Answer 37

species specific PCR if you don’t see the organism in RBC & capillary blood test from the ear or nail bed to look for the organism

Question 38

picture of babesia – what is this organism seen in this blood smear?

Answer 38

babesia

Question 39

what infectious process in cats mimics IMHA? how do you treat this?

Answer 39

mycoplasma – treat all cats with doxycycline or pradofloxacin prior to starting steroids

Question 40

what are some other disorders that mimic IMHA? how do they mimic it?

Answer 40

babesia in dogs, mycoplasma in cats, zinc, & copper toxicity can have spherocytes & agglutination