Final exam - transfusions / immune-mediated disease Flashcards
How quickly do you expect to see regeneration of RBCs?
3-5 days
What are the (very) general ddx for anemia?
Non-regenerative: various chronic dz processes
Regenerative: loss or lysis (immune-mediated, toxic)
What are the canine blood groups? What is considered the “universal donor”?
DEA 1.1, 1.2, 3, 4, 5, 6, 7, 8; DAL-Dal
Universal is DEA 4+, negative for all others (anti-DEA 4 do not cause hemolysis)
What are the feline blood groups? What is the “universal donor”?
Type A, B, AB; MIK
NO universal donor
Fill in the blank: NEVER transfuse __ blood to __ cats
NEVER transfuse A blood to B cats
Type B cats have HIGH levels of anti-A Ab’s (Brits hate Americans)
What are the 4 broad indications for transfusion?
- Anemia
- Coagulopathies
- Hypoalbuminemia - volumes to raise plasma albumin levels are tremendous, don’t use for this reason alone
- Thrombocytopenia - may last only minutes to hours, use only in crisis
How are canine blood donors selected?
> 25 kg lean body weight
Normal/healthy - routine CBC/chem/UA/fecal
Neg for HW, Lyme, Borrelia, Rickettsial dz
DEA 1.1, 1.2, and 7 negative
Greyhounds - usually universal donors, lean with good veins, PCV often higher
How are feline blood donors selected?
> 4.5kg lean body weight
Indoor only and neg for FeLV/FIV, T. gondii, Bardonella
Normal/healthy - routine CBC/chem/UA/fecal
Males preferred
How much blood (based on BW) can be donated?
1% of BW (10% of blood volume, BW is 10% blood)
What is in plasma?
Everything but RBC (WBC, hemostatic factors, albumin, globulins, etc.)
What is in cryoprecipitate?
vWF and factor VII
What is in cryosupernatant?
Factors II, VII, IX, XII; albumin, globulins
What supplementation is recommended for blood donors?
IV crystalloids while donating
Ferrous sulfate supplements
What does the major crossmatch test?
Recipient sera + donor RBC
What does the minor crossmatch test?
Donor sera + recipient RBC
When should transfusion be considered? Clinical signs and clin path findings
- Tachycardia, tachypnea, dyspnea
- Depressed from anemia
- PCV <12-15% (chronic) or acutely drops
How can you calculate how much blood to transfuse? (Real equation and quick estimation)
mL needed = recipient blood vol x [(desired PCV - current PCV) / PCV of donor]
*1mL (FWB) per pound raises the PCV by 1%
10-20 mL/kg FWB is the general indication
What immunologic complications are associated with blood transfusion?
Fever
Hemolysis
Acute hypersensitivity
Immunosuppression
What non-immunologic complications are associated with blood transfusion?
Circulatory overload Bacterial contamination Transmission of infectious diseases Citrate toxicity (hypoCa) Pulmonary microembolism / TRALI
What CS are associated with a transfusion complication?
Body temp increases >1ºC
Tachycardia, tachypnea, vomiting develops
Hemoglobinuria
Anaphylaxis: hypotension, urticaria, respiratory distress
How are transfusion complications treated?
STOP the transfusion (duh.)
Give crystalloids (or colloids if low BP)
Diphenhydramine for anaphylaxis
Dexamthasone sodium phosphate / epinephrine for shock
Pred acetate for urticaria only
What is oxyglobin? How does it work?
Polymerized bovine hemoglobin - no crossmatch needed, long shelf life
Increases free HgB
When are hetastarch/vetstarch indicated?
Hypotension, hypoproteinemia, hypoalbuminemia (*<1.5 albumin = fluid loss)
Used to maintain fluid within vascular space
When is human albumin indicated?
OFF LABEL use for hypoalbuminemia and resuscitation
What are the etiologies for IMHA?
Primary - immune-mediated
Secondary
-Medications (sulfas, etc.), toxins, venom
-Immunologic (SLE, etc.)
-Infectious (FeLV, Babesia, Lepto, etc.)
-Neoplastic (lymphoma, hemangiosarc, etc.)
What is the clinical history of a patient with IMHA?
Lethargy, weakness, pale mms, +/- hemolysis (pigmenturia and icterus)
How is IMHA diagnosed?
Anemia (usually regenerative)
- autoagglutination
- spherocytosis (dogs only)
- Coombs test (60-80% positive)
What additional workup should be done once IMHA is diagnosed?
- Imaging to look for secondary causes
- Coag panel to r/o blood loss and recognize DIC
- Arterial blood gas/SAO2 to detect pulmonary thromboembolism
What is the cause of death in most cases of IMHA?
Hypercoagulability and thromboembolism
What is Virchow’s triangle?
Describes parameters that predispose thromboembolism
- Endothelial damage
- Blood stasis/altered flow
- Hypercoagulability
What is the general treatment strategy for IMHA?
Treat secondary cause
Immunosuppression:
-Glucocorticoids (2-4 mg/kg/day)
-Azathioprine
What adjunct therapies are used in IMHA cases?
- Blood products to minimize tissue hypoxia
- Gastric protectants
- Aspirin/clopidigrel (anti-thrombotics to prevent TE)
What is the prognosis for IMHA? What are some NPIs?
50% in hospital mortality
NPIs: bilirubin >10mg/dL, autoagglutination
What are the main differences in feline IMHA?
Affects male cats <50% regenerative anemia Lymphocytosis common Rarely TE Lower mortality
What are the general ddx for thrombocytopenia?
- Destruction (immune-mediated, infectious, drugs)
- Consumption (DIC, neoplasia, loss d/t bleeding, sequestration)
- Decreased production (bone marrow dz, drugs)
What are the etiologies of ITP?
Primary -autoimmune -idopathic -genetic? Secondary -infection (Anaplasma, E. canis) -neoplasia -drugs (sulfas, cephs)
What clinical signs are consistent with ITP?
Petechia, ecchymosis
Lethargy/anorexia, bruising, anemia
How is ITP diagnosed?
Presumptive dx by r/o other causes
- CBC, tick panels, UA
- coag profile
- imaging
- bone marrow
How is ITP treated?
- eliminate underlying risks
- minimize bleeding
- immunosuppression
- glucocorticoids (2-4mg/kg/day)
- azathioprine - Minimize adverse effects
- GI protectants, pRBCs, O2, etc.
What is the prognosis of ITP?
Most improve within 7-10 days
Mortality ~30%
What clinical signs are consistent with SLE?
Polyarthropathy, skin lesions, proteinuria, blood dyscrasias (anemia, thrombocytopenia)
How is SLE diagnosed?
ANA (not very reliable)
Definitive dx: +ANA and 2 body systems with immune dz
How is SLE treated?
Immunosuppression
-Prednisone
-Azathioprine / cyclosporin
Levamisole (anti-parasite, immunomodulator)
What is the prognosis for SLE cases?
Guarded. Relapses common, often require long-term therapy
What are the general ddx for polyarthropathies?
Infectious (tick) Osteoarthritis Immune-mediated: -SLE -Erosive (rheumatoid) -Non-erosive (infectious, hepatic/GI-associated, neoplasia)
What clinical signs are associated with IMPAs
Lameness, fever, joint pain
What is the general workup for IMPAs?
CBC (non-specific) Chem (liver up) U/A (proteinuria) Joint rads Tick panel Arthrocentesis
How do arthrocentesis results differ between primary/secondary IMPA and rheumatoid arthritis?
Primary/secondary IMPA > non-degenerate neutrophils
Rheumatoid > degenerate neutrophils
How is IMPA treated?
Prednisone (immunosuppressive)
Azathioprine (careful of hepatotox) / mycophenolate
What is the prognosis for primary IMPA?
Good!
What signalment is associated with erosive (rheumatoid) arthritis?
Small/medium breeds
Greyhounds, Shelties
What is the pathogenesis of rheumatoid arthritis?
RFs and anti-IgG antibodies contribute to immune-complex formation in joints > synovitis and erosive joint changes
How is rheumatoid arthritis diagnosed?
MDB like IMPA
Rads (early may not show erosions)
Joint tap (degenerate neutrophils)
RF factor positive
How is rheumatoid arthritis treated? What is the prognosis?
No specific tx - pain management, immunosuppression may slow progression
POOR prognosis
