ITE Heme COPY Flashcards
Antibody screen negative meaning
PATIENT has no sig RBC antibodies
*the RBC has surface antigens (A, B, Rh)
the RBC has surface antigens (A, B, Rh), which one is most likely to produce immunization?
Rh
- if pts are Rh(D) negative, they do not express Rh(D) antigen on their RBC surface
What does it mean if a patient is type A blood?
They have A antigen on their RBC surface
- can accept type A and O blood
They lack B antigen
- would make anti-B antibodies
- If transfused with nonmatching blood, their antibodies will attack donor blood -> massive hemolysis
How does type and cross work? How long does it take?
Mixing DONOR erythrocytes with RECIPIENT’S plasma
- Agglutination occurs if there is a minor or major incompatibility
Takes 45-60 min
Universal donor
Universal recipient
Type O
Type AB
How does type and screen work?
Determines pt’s ABO and Rh(D) status
Mixes PATIENT’S plasma with 2-3 reagent samples of RBCs (clinically important RBC antigens)
If type and screen is already performed and the patient emergently needs blood, _________ is the best option if a full cross match (50 min) cannot be performed.
type-specific partially cross-matched blood transfusion
All blood in the US contains ____ that serves as a buffer,
____ that acts as a RBC energy source, and
_____ that acts as an anticoagulant
Phosphate
Dextrose
Citrate
How long can pRBCs be stored for?
21-35 days
What anesthetics will trigger acute attacks in porphyrias? (8)
- Etomidate
- Benzos
- Ropivacaine
- Phenytoin
- Sulfonamides
- Ethanol
- Amphetamines
- Ergot derivatives
*fent, prop, gas are okay
TEGs - What do you give if:
- R time is too long
- a- angle is too low
- Max amplitude too high
- Breaking down clot too quickly (hyperlytic)
R time: FFP
- clot beginning to form
- has clot products (IX, X
a-angle: Fibrinogen
- how quickly clot is forming
- often given with FFP
MA: Platelets
- width of clot
- Maximal clot strength
Antifibrinolytic (TXA or aminocaproic acid) to prevent lysis
- clot lysis speed
TEGs: appropriate values
- R time
- a- angle
- Max amplitude
- Clot break down time, LY30
“Rule of 6’s”
- R time: 6 min
- a- angle: 60 degrees
- Max amplitude: 60 mm
- LY30 (Clot break down): 6%
Cryo has what factors in it?
VII, vWF
MOA of TXA?
Antifibrinolytic
- direct plasminogen and plasmin inhibitor
- prevent fibrin break down
- control of hemorrhage
MOA of protamine
antidote to heparin
Chelates large, negatively charged heparin molecule and prevents binding with antithrombin 3
MOA of vitamin K clotting cofactor
Increases activation of clotting factors 1972 (X, IX, VII, II)
- cofactor for those factors
tPA MOA? Effect on TEG?
accelerates fibrinolysis
- (enzymatic catalyst for conversion of plasminogen to plasmin -> binds fibrin -> breakdown)
- increased LY30 (clot break down). (normal is 6%)
TXA or aminocaproic acid MOA?
Antifibrinolytic.
- Lysine analog that directly binds to activated plasmin in the place of fibrin -> prevents fibrin breakdown
tPA can cause hemorrhage d/t increased fibrinolysis. How do you reverse tPA?
antifibrinolytic like TXA or aminocaproic acid
Protamine MOA
large, positively charged molecule that chelates large negatively charged heparin and prevents binding with AT3 and subsequent anticoagulant effect
Desmopressin (DDAVP) MOA
induces synthesis and release of VWF by endothelial cells
- critical role of platelet adhesion
What is contraindicated in Acute intermittent porphyria?
anything that induces P450 d/t increasing ALA concentration
- Alcohol
- Barbiturate
- BDZ
- Nifedipine
- Glucocorticoids
How does fructosamine testing in diabetes work? Who is it used in?
Measures shorter time interval compared to hgb A1c.
Pts who have reduced red cell lifespans (hemolytic anemia, sickle cell disease)
How can the sequestration of platelets spare autologous blood products from damage during CPB?
This creation of a platelet-rich plasma can help protect the platelets from damage during bypass.
Infuse platelets after bypass to conserve blood
