Lecture 3b Flashcards
What are the types of blood transfusions?
Homologous transfusion
Autologous transfusion (planned surgery)
What substance helps prevents blood coagulation?
Sodium citrate
What are the major blood group systems?
ABO
Rh
What do we do for pre-transfusion testing?
Typing: Ensures ABO/Rh compatibility
Antibody screen: for unexpected antibodies
Crossmatch: tests patients serum against prospective unit
How do we screen antibodies?
Mix blood with type O abc that has major antigens of other blood group systems and observe if theres clumping and agglutination
How do we cross match?
Take donors blood and mix with recipient blood to make sure it matches
(Not ordered in emergencies)
Why do we transfuse?
Replace acute blood loss
O2 delivery
Morbidity and mortality
Who do we transfuse?
Usually if hgb levels are <8
For sure if hgb <6
What is an optimal transfusion?
Providing enough RBC to maximize outcome while avoiding unnecessary transfusions
What does it mean when someone hgb level doesn’t go up after transfusion?
It means the pt is actively bleeding somewhere
How much goes hgb increase when taking 1 unit of RRBCs? How long should it be given over?
1g/DL given over 1-2hours
Do we need consent to perform transfusion therapy?
Yes, signed consent unless it’s an emergency
When do transfusion reactions usually occur?
Within 24hours of the transfusion
What are the usual reactions after a transfusion?
Fever
Chills
Pruritus
Urticaria
If a transfusion reaction is suspected what do you do?
Stop the transfusion and report it to the blood bank
What are the possible risks of transfusion?
Hemolytic transfusion reaction (incompatible blood)
Febrile non-hemolytic reactions (most common, due to cytokines in recipient)
Allergic reactions (from urticaria to anaphylaxis)
Infectious complications (septic reactions, viral transmission[hepB,C, HIV])
Transfusion related acute lung injury
Circulatory overload (most common in death)
Transfusion associated graft vs host disease
Post transfusion purpura
Iron overload (check serum ferritin levels)
Hyperkalemia or other electrolyte toxicity
Hypothermia
What are the types of blood products?
Whole blood
Packed red blood cells (PRBCs)
Fresh frozen plasma (FFP)
Cryoprecipitate
Platelets
What are characteristics of whole blood?
O2-carrying capacity and volume expansion
Rarely used, only in massive hemorrhage
Usually processed down
How is whole blood stored? What are some cons about that?
Stored at room temperature, but platelets become dysfunctional and clotting factors become degraded
However it does increase O2 affinity of hgb of RBCs
What do you usually give to anemic patients?
Packed RBCs
What are some characteristics of PRBCs?
Usually used in most clinical situations
Increases O2-carrying capacity in anemic pts
Each unit is about 200mL
Has modified forms
What are the possible modifications that could be orders for PRBCs?
Leukocyte reduced: to reduce risk of immune effects(now usually universally preformed)
Irradiated: avoiding GVHD who have immune deficiency
Washed: getting rid of proteins present in small amount of residual plasma
What are characteristics of plasma products?
Has platelets and proteins (procoagulant and anticoagulant factors)
Plasma centrifuged to give one unit of platelets and one unit of FFP
What is the universal donor for plasma?
AB+
What are the characteristics of FFP?
From fresh blood removing the RBC, WBC, and platelets
Has coagulation factors, fibrinogen, antithrombin, albumin, protein C + S
Frozen and thawed when needed
Corrects deficits of any circulating coagulation factors
Why does FFP need be transfused within 24hours?
Factor 5, 8 will begin to decline
What is cryoprecipitate?
White precipitate collected when thawed FFP at 4C
Rich in von willebrand factor, factor 8,9,1(fibrinogen)
What are factor concentrates?
Large amount of specific clotting been produced with recombinant technology or collected from thousands of donors pooled into a highly conc. produced
What are factor concentrates indicated for?
Replace factor deficiencies with min. vol and without extraneous proteins
Example: hemophilia A and B
Who is indicated for a platelet transfusion?
<10k to prevent spontaneous hemorrhage
<50k who are actively bleeding, invasive procedure, or intrinsic platelet disorder
<100k who have a CNS injury, multi system trauma, or going nuerosurgery
Normal platelet count if they have active bleeding and platelet dysfunction
What are examples that cause platelet dysfunction?
Congenital platelet disorder
Chronic aspirin therapy
Uremia
How much does platelet count increase from one unit of transfused platelets?
5k to 10k
If someone is bleeding and have 25k platelet count going to operative colonoscopy, how many units of platelets do you order?
At least 5 units
What are the hemostatic promoting agents?
Protamine sulfate
Vit k
Desmopressin
Thrombin
What is protamine sulfate indicated for?
Neutralizes heparin (heparin reversal agent)
Antitode for heparin overdosage
Used for heparin neutralization during surgery or dialysis procedures
What is the BBW for protamine sulfate?
Severe hypotensive or anaphylactoid-like reactions
What is Vitamin k indicated for?
Reversal agent for warfarin
What is mephyton?
Drug used to treat Vitamin k deficiency
When do you usually give desmopressin?
Usually before procedures
What is the MOA of topical thrombin?
Converts fibrinogen to fibrin directly at the site of bleeding
What are the types of antithrombotic drugs?
Antiplatelet drugs
Anticoagulants
Fibrinolytic agents
What are anticoagulants indicated for?
Prevent or treat clot/thrombus
What are anticoagulants CI for?
Bleeding
Impaired renal function
Allergic reaction to drug
What are the parenteral anticoagulants?
Heparin (unfractionated)
Low-molecular-weight heparin (LMWH) (Enoxaparin/Lovenox)
Bivalirudin (Angiomax)
Argatroban (Acova)
What is the MOA of unfractionated heparin?
Binds to anti-thrombin (III) and enhances its inactivation of factor 10a and thrombin
What setting is unfractionated heparin given in?
Inpatient setting
What do we order for unfractionated heparin monitoring?
Activated partial thromboplastin time(aPTT)
Anti-factor 10a level
What are some adverse effects of heparin?
Bleeding (do daily CBCs, ask if black stool)
Thrombocytopenia
Osteoporosis (usually if on drug for long term)
Elevated LFTS
What is Heparin-Induced Thrombocytopenia (HIT)?
Drug-induced thrombocytopenia from taking heparin
When does HIT occur?
With any dose, schedule, or administration route
More common in females
What do we do when we suspect Heparin-Induced Thrombocytopenia (HIT)?
Stop heparin
Order…
HIPA
Serotonin release assay
Heparin-PF4 ab ELISA
What drugs do we give instead if they need anticoagulation but cant take heparin?
Argatorban
Bivalirudin
Fondaparinux
How much LMWH?
Depends on indications
But reduce dosing if they have renal impairment
CI with ESRD
What do we measure to check LMWH levels?
Amount of factor 10
What is the MOA of argatroban(Acova)?
Direct, selective thrombin inhibitor
Reversibly binds to the active thrombin site of free and clot-associated thrombin
Inhibits fibrin formation
Activates coagulation factors V, VIII, and XIII
Activates protein C and platelet aggregation
What do we measure when a patient is taking warfarin?
PT/INR
What dietary substances can affect warfarin?
Ethanol: increase/decrease
Vitamin E: increase
Cranberry juice: increase
Vitamin K: decrease
What is the MOA of dabigatran?
Direct thrombin inhibitor
What is dabigatran indicated for?
Stroke prevention in nonvascular atrial fibrillation
DVT/PE
DVT/PE prophylaxis after hip or knee arthroplasty
What do you need to do to dibigatran when a patient has a renal impairment?
Reduce dosage
What are the adverse events in taking dabigatran?
Bleeding (especially in GI)
What is the MOA of Rivaroxaban?
Oral factor Xa inhibitor
What drug can you give when pts have uncontrolled bleeding from dabigatran?
Praxbind
What is Rivaroxaban indicated for?
Same as dabigatran
What is contraindicated for rivaroxaban?
Active pathological bleeding
What drug can be given to those affected with a factor Xa inhibitor and needs it to be reversed?
AndexXA
What is the MOA for apixaban?
Oral factor Xa inhibitor
Inhibits platelet activation and fibrin clot formation via direct, elective and reversible inhibition of free and clot-bound factor Xa
What is apixaban indicated for?
Same as dabigatran
What is apixaban contraindicated in?
Active pathological bleeding
What is special about cangrelor?
Only one given IV in its class
