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
Dietary supplements that interfere with platelet function (4)
- Garlic
- Ginger
- Ginko
- Vit E
St John’s Wort is used to tx depression and PMS. Drug interactions?
Potent CYP3A4 inducer -> increased metabolism and decreased efficacy of meds
- Digoxin
- Warfarin
- Cyclosporin
- Anticonvulsants
(Right/Left)ward shift of oxyhemoglobin dissociation curve is found in pts with chronic severe anemia
Rightward
- decrease affinity of hgb for oxygen -> facilitates release of oxygen to tissues
Can pts develop cardiomegaly in chronic severe anemia?
Yes - high outpt cardiac failure secondary to decreased blood viscosity
- Pulm congestion
- Ascites
- Edema
- Orthopnea + dyspnea
In general, a positive direct antiglobulin test (Coombs test) is diagnostic for _____
a hemolytic reaction
- if negative, then pt has non-hemolytic rxn
Transfusion related acute lung injury (TRALI) - leading cause of transfusion related death usually w/in 6 hours
- What is it d/t?
Antibodies in donor blood bind to recipient’s leukocytes -> adhere to vascular capillary bed in pulmonary circulation
________ is the most common blood reaction. Fever, chills, headache, myalgias
non-hemolytic febrile transfusion reaction
- negative Coombs test
- Recipient antibodies against HLA antigens on donor leukocytes -> cause lysis of donor leukocytes
Polycythemia vera is a hematological condition that causes which blood cell lines to proliferate?
All three
- Erythrocytosis
- Leukocytosis
- Thrombocytosis
Mild allergic transfusion reactions (urticaria, pruritus, facial swelling) are d/t?
Soluble foreign proteins in transfused donor blood
- acts as antigen -> immune activation in recipient via IgE response
In pts with sickle-cell disease, with mod-high risk procedures, you should transfuse to hgb level of ___
10 g/dL
Which more commonly causes HIT, Unfractionated heparin or LMWH?
Unfractionated
- 10x more
Two tests that can detect HIT. Which one is more sensitive? Specific?
- Anti- Platelet factor 4
- Serotonin release asay
Both are sensitive
SRA is more specific
When does an acute hemolytic transfusion reaction occur? (immediate, N/V, chills, fever)
When previously sensitized individual with circulating antibodies to either A or B antigens on donor erythrocytes is transfused blood containing that major antigen.
Tests to run if you suspect hemolytic transfusion reaction?
- Direct antiglobulin (Coombs) test
- Repeat crossmatching
- Hemolysis tests (haptoglobin, bilirubin, urine hgb)
Indication for platelet transfusion in the setting of massive transfusion is ____
< 75,000/mcL
Tope 3 causes of death associated with blood products
- TRALI
- Hemolytic transfusion reactions (non-ABO > ABO)
- Infection/Sepsis
PCWP is a measure of the LAP.
- Normal PCWP: ?
- What is it in pts with TRALI?
5-12 mmHg
<18 mmHg
*FYI: CHF and pulmonary edema pts have PCWP > 25mmHg
What can help differentiate TRALI from TACO since they both can cause b/l pulmonary infiltrates?
BNP - elevated in TACO
What can be given to pts with heparin resistance (antithrombin III deficiency)?
FFP or antithrombin III
Maximum allowable blood loss equation
[EBV * (starting Hct - target Hct)] / (starting HcT)
ie:
= [70ml/kg x 70kg * (42 - 30)] / 42
= [4900 mL *12 ] /42
Cryoprecipitate contains ____ mg/unit of fibrinogen.
200 mg/u
- ie: if you give 10 u of cryo, you are giving pt 2000mg of fibrinogen
Cryoprecipitate has factors ____
VIII, fibrinogen, vWF
What is leukoreduction of blood products? Benefits?
Decrease or complete elimination of donor leukocytes in blood components
- reduces risk of febrile transfusion rxn and risk of viral transmission (CMV)
*does NOT prevent graft vs host disease and some bacteria
Tx for TACO
diuretics
- problem is overload in circulating volume regardless of type of blood product
Warfarin reversal for urgent surgery
- INR 1.5 - 1.9:
- INR 1.9 - 5:
- INR 5 - 9:
- INR 1.5 - 1.9: PCC
- INR 1.9 - 5: PCC or FFP + 1-3mg of IV vit K
- INR 5 - 9: PCC or FFP + 2-5 mg IV Vit K
Warfarin reversal for surgery (24-48h later):
- INR 1.5 - 1.9:
- INR 1.9 - 5:
- INR 5 - 9:
Warfarin reversal for urgent surgery
- INR 1.5 - 1.9: 1mg PO Vit K
- INR 1.9 - 5: 1-2.5 mg PO Vit K
- INR 5 - 9: 2.5 - 5mg PO Vit K
