21- An Introduction to Transfusion Medicine Flashcards
What are the requirements to be able to donate blood? How much blood is taken and how frequently can you donate whole blood?
age>16 yrs
pass a limited history/physical (questionnaire, general appearance POC, BP, Hb)
donation for whole blood= 8 week intervals
apporx 500 ml of blood is taken
How do we manufacture a blood product?
Centrifugation! We separate Cells from plasma
What 9 diseases do we test blood products for?
Syphillis
Hepatitis B
Hepatitis C
HIV
HTLV-I/II
West Nile Virus
Trypanosoma cruzi
Zika Virus
Babesia microti
What antigen(s) and antibodies does group A blood have?
A antigen (on RBC)
Anti-B antibody (in plasma)
What antigen(s) and antibodies does group B blood have?
B antigen (on RBC)
Anti-A antibody (plasma)
What antigen(s) and antibodies does group AB blood have?
A and B antigen (on RBC)
No antibodies!
What antigen(s) and antibodies does group O blood have?
No antigens! (on RBC)
Anti-A antibody and Anti-B antibody , Anti-AB antibody
(I have never heard of anti-AB antibody but I put it on here bc it was on this picture, not sure if it is real. but what do I know I’m not a doctor)
How important is the ABO red cell blood group system?
When do people develop their antibodies?
Most important red cell blood group system!
Antibodies are naturally occuring, very potent, and can activate complement
(responsible for many acute/fatal hemolytic transfusion reactions)
What is the most important antigen for Rh blood typing? When do people develop antibody?
You either have the Rh antigen (D antigen) (+) or you don’t (-)
D is immunogneic-80% sensitization
antibodies develop thorugh pregnancy or trans fusion (aka exposure)
implicated in hemolytic disease of the newborn and hemolytic transfusion reactions
Pre-transfusion testing can be “type and screen” or “type and cross” what thing do we type and screen for?
ABO and Rh
Antibody screen
low likelyhood for transfusion ie pre-op for cholecystectomy
Pre-transfusion testing can be “type and screen” or “type and cross” what thing do we type and cross for?
ABO and Rh
Antibody Screen
Cross Match
Moderate to high likelyhood for transfusion likelihood (ie pre-op heart surgery)
What is done for pre-transfusion testing? Write out the path if the antibody screen was negative
Patient blood sample
perform ABO/D typing
perform antibody screen ***negative**
select ABO/D compatible product
perform cross-match
issue RBC product
What is done for pre-transfusion testing? Write out the path if the antibody screen was positive
Patient blood sample
perform ABO/D typiing
Perform antibody screen (unexpected antibodies) **positive**
perform antibody identification panel
Select ABO/D compatible, antigen-negative RBC product
perform cross-match
issue RBC product
How do we test for ABO?
Add in A, B and AB cells to the patients plasma/serum and see what clumps
clumping signals that the patient has antibody against whatever cell type was added
What is the IAT Antiglobulin Test (IAT)? Screen
The IAT detects red cell antibodies in the patient’s serum
(we are adding known cells to the patients serum and looking for response)
uses: antibody screen/panel, compatibility testing
What do you do if the IAT antibody screen is positive?
an antibody identification panel (another bigger IAT)
What is crossmatch?
- Another IAT
- Final test: is the blood that we selested for your patient?
- units are screened for antigen if Abs identified (via the IAT)
- confirmation/Ab specificity not ID’d on AB screen
- crossmatch may be omitted under certain circumstances
so add in donor cells to the patient’s serum. these are not the same cells from the IAT, these are cells from a volunteer that we don’t know a lot about
What does the DAT detect? What are 4 causes?
antibody attached to patient red cells in vivo
Autoimmune Hemolytic Anemia
Drug Induced Hemolytic Anemia
Hemolytic Transfusion Reactions
Hemolytic DIsease of Newborn
(we add atibodies to patient whole blood)
Why is it important to plan ahead for pre-transfusion testing?
It can take an hour! and that is if nothing is found on the IAT!
You need to get one of these every 3 days while transfusions are needed
What does emergency release blood mean?
skips all the steps to get you blood fast!
uncrossmatched
red cells=O (mostly pos), plasma=ABA/A
What does Massive support mean?
Friends like Drs. Pook and Matter <3 but also…
helpful at times of severe, uncontrolled bleeding
uses emergency blood components in a ratio to prevent coagulopathy
10RBCs/6plasma/1plt, or 6 RBCs/6plasma/1plt
What blood products can you get?
Red blood cells (RBCs)
Plasma (FFP)
Platelets (Plts)
Cryoprecipitate (Cryo)
(aldo whole blood and granulocytes)
How do we prep and store RBCs? What do they contain? what is their outcome?
Prep: Cells separated by centrifugation, plasma removed, stored at 4C for 42 days
Contains: 300ml, HCT 55-60%, no viable platelets for WBCs
Outcome: transfuse over 3-4hrs, raise Hgb 1g/dl in average size adult
What blood type is the universal recipient and the universal donor?
Donor: O-
Recipient: AB+
When should patients be transfused with RBCs?
- acute,rapid, blood loss
- symptomatice perioperative anemia
What are the suggestions for RBC transfusion during acute rapid blood loss?
to increase o2 delivery (>7)
anemic pts with hemodynamic instability
15-30% loss: not required
30-40% loss: probably required
>40% loss required
What are the suggestions for RBC transfusion during symptomatic/perioperative anemia?
single unit transfusions with H&H/ symptom rechecks
decisions should be guided by symptoms, vitals, labs
Hgb<7 transfusion indicated
What are 3 reasons you should NOT give RBC transfusion?
based only on Hemoglobn levels
as volume expander (use saline)
as a means of improving iron/B12/folate
What is the prep/storage, contents, and outcomes of plasma transfusion?
prep: plasma separated from whole blood by centrifugation, red cells removed. store at -18C for 12 months, stored at 4C for 5 days
contains: 250ml plasmaproteins, no platelets, RBCs, or WBCs
outcome: 10-20ml/kg rasises all clotting factors by 20-30% in average size adults
So what is in plasma?
all coagulation factors! (including fibrinogen, fibronectin, vWF)
all thrombolysis factors (Protein C, S, plasmin)
antibodies
cytokines
proteins (albumin)
who is the universal PLASMA donor? recipient?
Donor: AB
Recipient: O
When are plasma transfusion helpful for:
active/expected bleeding and documented coagulopathy (INR>1.7 or PT and/or PTT greater than 1.5 times upper limit of normal range)
- cases of massive hemorrhage
- pts with mulitple coagulation factor deficiencies (liver failure, DIC)
- isolated deficiency with no available concentrate (V, ADAMTS13-TTP)
- Angioedema (ACE or congenital)
When are plasma transfusions NOT helpful?
- as a volume expander (use saline/albumin)
- to quickly reverse Heparine (use protamine), Warfarin (use PCC if urgent Vit K if not), other anticoagulants (ie dabigatran)
- Mildly elevated INR or PT/PTT
- Routine paracentesis or variceal band ligation
how do INR and plasma transfusions relate?
Plasma ha a low INR so it won’t necessarily fix the pts INR
FFP never completely correct PT in pts with severe liver disease
PT/INR is not directly correlated with bleeding incidence and severity
Cryoprecipitate
prep/storage
contains
outcome
prep: fluid separated thawing plasma slowly , stored at -18C for 12 months, room temp for 4 hours
contains: 15-20ml/unit, enriched for Fibrinogen, noviable platelets, RBCS, WBCs
Outcome: 1 unit/10 kg will raise fibrinogen by 50mg/dL in an average size adult
So what is in cryoprecipitate
a big bag of fibrinogen!!
there is also this stuff…
What are the 4 indications for cryoprecipitate?
- Hypofibrinogenemia with bleeding (DIC, Severe liver disease, massive bleeding/obstetric bleeding)
- Dysfibrinogenemia with bleeding (acquired-liver disease, congenital)
- Factor XII deficiency
- Not indicated for hempphilia A or VWD
How do we store platelets? Outcome?
prep/storage: cells separated by centrifugation of whole blood or apheresis, stored at room temp for 5 days
outcome: raises plt count 30,000-60,000 in an average size adult
what is contained in a unit of platelets?
random donor unit: 5.5* 10^10 platelets in 50-70ml plasma
single donor platelets: 3*10^11 platelets in 300 ml plasma
no viable RBCs, or WBCS
When do we transfuse platelets?
active bleeding
marrow failure patients
prophylaxis before surgery
what are the guidelines for transufusion of platelets during active bleeding?
platelet count< 50,000
platelet function defect (platelet inhibitor medication, cardiac bypass circuit, congenital platelet disorder)
What are the guidelines for platelet transfusion in marrow failure patients?
<10K transfusion indicated
10-20K if bleeding history, fever, mucositis
What are the guidelines for platelet transfusion prophylactically before surgery?
<50K: general surgery, procedures
<100K: Eye, CNS, high risk surgery
any count: platelet inhibitory drugs or congenital platelet dysfunction (aspirin, plavix)
What are 4 contrandications to platelet transfusion
TTP
HIT
ITP
PTP (post transfusion purpura)
ina all these cases either the platelets are quickly consumed or there may be an increased risk of thrombosis (ie HIT)
Define these words that are related to blood products (sorry didnt kno how else to do this slide)
Leukoreduced
CMV negative
CMV safe
irradiated
volume reduced
washed
fresh
Leukoreduced- less WBCs all products are leukoreduced
CMV negative- tested product is negative
CMV safe: donor or product is negatvie but product was not tested
irradiated: to prevent GVHD!
volume reduced: in fluid sensitive patients
washed: if your patient has a lot of allergies/ anaphylaxis
fresh: old products RBCs may lyse leading to increase K, so fresh blood is good for K sensitive people
What things cause acute infectious transfusion reactions? Delayed (days-weeks)
acute: bacteria/sepsis
delayed (days-weeks): Hepatitis B, C, HIV
What are 5 Acute (hours) non-infectious transfusion reactions
Simple fever (FNHTR)
Hemolysis (AHTR)-rejection
Cardiac overload (TACO)
Acute lung injury (TRALI)
Allergic/anaphylaxis
What are 4 delayed non-infectious transfusion reactions?
GVHD
Iron overload
Hemolysis (DHTR)
Post transfusion purpura
What adverse transfusion events are associated with fever?
FNHTR (benign)
Hemolysis (deadly)
Sepsis (deadly)
either way STOP THE TRANSFUSION if they have a fever
What adverse transfusion events are associated with dyspnea?
TRALI
TACO
Anaphylaxis
What adverse transfusion reactions are associated with prupritis?
allergy/anaphylaxis
Which adverse reactions are the most deadly?
Dyspnea associated one! TACO and TRALI
TRALI IS NUMBER 1
What is the most common adverse transfusion reaction?
allergies/hives
Which infection is most common to get from an infusion?
Hep B
What are the symptoms of TRALI?
acute respiratory distress and hypoxemia (wet crackles/rales, pink frothy sputum)
hypotension
fever/chills
What is the pathogenesis of TRALI? idk if we need to know this……
nothing helps with the fluid overload so hopefully in 3-7 days it will pass
What is the difference between acute hemolytic reaction and delayed hemolytic reaction?
Acute=rapid (1-2hrs), intravascular, ABO error
Delayed= late (5-7 days), extravascular, undetected antibody at XM
How do we prevent Ta-GVHD?
Irraditation of blood products and pathogen inactivation
**he skipped this slide so I am attaching it but i dont htink we need to know it!
Who is at risk for Ta-GVHD?
Seems to me like anyone who is receiving immunotherapy for any reason…again he skipped this slide. sorry
what is the pathophysiology of Febrile non-hemolytic reactions?
IL1, 6, TNF from activated mono/macro. passive/induced donor cytokines from donor WBC
