Transfusion Flashcards
Reasons to warrant Rho gam (other than 28 week dose)
- Procedures (amniocentesis)
- Abortion (spontaneous or induced)
- Accidental transfusion of Rh+ blood
- Blunt abdominal trauma
- Ectopic pregnancy
- Threatened pregnancy
- Molar pregnancy
- Fetal demise in T2/T3
- Antipartum hemorrahge in T2/T3
How much blood will a standard (300mg) vial of rhogam work for?
15mL rh + RBC (30mL fetal D+ whole blood)
Blood screening for pathogens - Name 6 pathogens and the screening test used for each
- HIV 1/2 – PCR/NAAT +serology
- HCV – PCR/NAAT +sAg, cAb
- HBV – PCR/NAAT +serology
- HTLV-I/II – Serology
- WNV – PCR/NAAT (seasonal)
- Chagas disease if RF’s- Ab testing
- Syphilis- Serology
- Bacterial culture- platelets only
- Plasma for fractionation- parvo B19
- don’t test for CMV as eliminated with leukoreduction
- ? Test for Zika
Features of TA-GvHD
- Pancytopenia
- Diarrhea
- Rash
- Elevated liver enzymes
- Mucositis
- Fever
Donor lymphocytes attack recipient antigen-presenting tissue (skin, GI, liver, bone marrow) in a immunocompromised recipient who can’t stop donor lymphocyte engraftment, or if there is partial HLA match between donor and recipient (recipient’s cells don’t recognize donor as foreign, but donor cells do)
List 4 complications of massive transfusion (excluding transfusion reactions)
Hypocalcemia Hyperkalemia Acidosis Dilutional coagulopathy/thrombocytopenia Hypothermia (impairs platelets, decreases citrate metabolism, increases hemoglobin affinity, impairs myocardial function) MO: development of allo-antibodies
If you irradiate RBC, what are two impacts on the red cell product?
- Decreased life span/shelf life of RBCs (28 days) but not plts. Give within 14 days of irradiating.
- Hemolysis leading to hyperkalemia, free hemoglobin
TITrE2 Trial, NEJM 2015:trial in CV surgery assessing the benefits of a restrictive (Hb < 75) vs liberal (Hb < 90) transfusion strategy. For the following outcomes, state whether liberal or restrictive strategies are superior, or if neither is. Infection risk Cardiac events ICU length of stay 30 day mortality 90 day mortality Myocardial infarction
Infection risk - no difference
Cardiac events - no difference
ICU length of stay no difference
30 day mortality- increased w restrictive
90 day mortality- increased w restrictive
Myocardial infarction- no difference
What are indications for rFVIIa
Hemophilia A or B with inhibitors
Patients with acquired hemophilia
Congenital factor VII deficiency
Glanzmann thrombasthenia with platelet refractoriness.
Post tranfusion purpura:
- Severity of thrombocytopenia:
- Onset and timing:
- Mechanism:
- Diagnosis:
- Treatment:
- Severity of thrombocytopenia: plt can be <20
- Onset and recovery: if caused by alloab to the transfused plts, the onset 5 to 10 days + lasts for days-weeks. If caused by passive transfer of an antiplatelet Ab, onset is within hours, and recovery is within days.
- Mechanism: i) Formation of immune complexes, adsorption of soluble platelet antigens onto autologous platelets; or
ii) induction of platelet autoantibodies. - Diagnosis:detecting circulating alloAb to a common platelet antigen, most often HPA-1a (and lack of this antigen on pts plts)
- Treatment: IVIG (rarely steroids but take 1-2 wks to work). If pt HPA1a neg, then give HPA1a neg plt for future transfusions.
Potential side effects of IVIG
- Infusion reactions with fever, rigors, headache
- Aseptic meningitis
- Renal complications with certain brands
- hemolytic anemia
- neutropenia
- VTE
Rare: anaphylaxis, bacterial sepsis
What is the factor that distinguishes 4 factor PCC from 3 factor PCC?
4-factor PCCs containing all vitamin K–dependent coagulation factors, and as 3-factor PCCs, which contain relatively low concentrations of factor VII
5 most common antigens in delayed HTR
Rh (34%), Kidd (30%), Duffy (14%), Kell (13%), Ss >>MN (4%) antigen systems
What isotype of immunoglobulins are the isohemaggultinins which healthy individuals produce against antigens not on their RBC surface? (ie. O individuals, produce what type of ABO immuoglobulins)
IgM antibodies!
Interestingly, O individuals produce an IgG anti-AB which cross reacts with both anti-A and anti-B and can cross the placenta which is why O mothers are more commonly implicated in HDFN. (IgM Abs, anti-A and anti-B cannot cross the placenta).
Rh, kell, kidd, duffy, MN are IgGs
What is the McLeod phenotype?
Defect in XK locus resulting in low or absent expression of the erythrocyte blood group Kell antigens, Kell(-).
RBCs are acanthocytic with decreased deformability and reduced survival, leading to a chronic but often well-compensated hemolysis.
*Must receive kell negative transfusions!
What is the formula for “corrected count increment (CCI)” used to measure platelet refractoriness?
CCI = body surface area (BSA; m2) × platelet count increment*10`11/number of platelets transfused.
Ex. 3 × 1011 platelets are Tx'd to a pt with a BSA of 1.8 m2, and the postTx increase in plt count is 23,000/μL, then the CCI =1.8 m2 × 23,000/μL / 1011/3 × 1011 = 13,800.
Plt refractoriness is defined as 2 or more consecutive postinfusion CCIs of < 5,000 to 7,500.
