Hemostasis and Transfusion Therapy Flashcards
What is a typing?
Ensures ABO/Rh compatibility by determining the recipients blood ype. Ex) A-
What is an antibody screen?
Tests for unexpected antibodies in the recipient plasma
What is a cross match?
Tests the patient’s serum against the prospective unit of blood for reactivity
Why do we transfuse (3)?
- Replace acute blood loss
- Oxygen delivery
- Morbidity and mortality
Who do we transfuse?
Hgb <6 always
Hgb 6-7 Likely
Hgb 7-8 Yes in post-op patients
Hgb 8-10 No except symptomatic anemia, ongoing bleeding, ACS with ischemia
Hgb >10 Almost never
When do we assess post transfusion Hgb?
15 minutes after transfusion as long as the patient is not actively bleeding
How much does 1 unit increase the Hgb?
1 g/dL
What are the risks of transfusion (11)?
- Transfusion reactions (1/14,000)
- Febrile non-hemolytic reactions
- Allergic reactions (urticaria to anaphylaxis)
- Infectious complications (septic reactions, viral transmission. Hep B/C and HIV are 1/1,000,000)
- Transfusion Related Acute Lung Injury (1/10,000)
- Circulatory overload
- Transfusion associated graft versus host disease
- Post transfusion purpura
- Iron overload
- Hyperkalemia or other electrolyte toxicity
- Hypothermia
When do transfusion reactions occur?
During or within 24 hours of transfusion
What are the types of blood product transfusions (5)?
- whole blood
- packed red blood cells
- fresh frozen plasma
- cryoprecipitate
- platelets
What is the purpose of whole blood?
O2 carrying capacity and volume expansion
Used in massive hemorrhage, otherwise rare because storage issues where platelets become dysfunctional and clotting factors degrade, Hgb gains oxygen affinity
What is the purpose of packed red blood cells?
Most common use
Increases oxygen carrying capacity
What is the volume of a unit of PRBCs?
200 mL
What are leukocyte reduced PRBCs used for?
used to reduce risk of immunologically-mediated effects, infectious disease transmission, and reperfusion injury
What are irradiated PRBCs used for?
Avoid graft-versus host disease in immunodeficient patients
What are washed PRBCs used for?
Prevent/eliminate complications associated with infusion of proteins present in the small amount of residual plasma
What is contained in the plasma?
Platelets and proteins including procoagulant and anticoagulant factors
What is in FFP?
Coagulation factors, fibrinogen, antithrombin, albumin, protein C, and protein S
What is cryoprecipitate?
Von Willebrand factor, factor VIII, factor XIII, and fibrinogen
Advantageous because smaller volume
What are factor concentrates?
A large amount of a specific clotting factor either produced by recombinant technology or pooled from thousands of donors.
What are the criteria for platelet transfusion?
<10,000 everyone gets due to risk of hemorrhage
<50,000 transfuse if bleeding, procedure planned, or have qualitative intrinsic platelet disorder
<100,000 transfuse if there is a CNS injury, multisystem trauma, or undergoing neurosurgery
Transfuse anyone with a normal platelet count but active bleeding and a known platelet dysfunction
How much does one unit raise the platelet count?
5-10,000
What is the indication for protamine sulfate?
Heparin reversal agent
What is the dose of protamine sulfate determined by?
The dose of heparin given
What is the BBW for protamine sulfate?
Can cause severe hypotensive or anaphylactoid reactions
What is vitamin K used for?
Reversal of warfarin
What is the dosage of vitamin K dependent on?
The severity of bleeding and INR level
What is desmopressin (DDAVP) MOA?
Increases vWF, VIII, t-PA leading to a shortened aPTTT and bleeding time
Think von Willebrand disease and hemophilia A
What must you do alongside giving desmopressin?
Restrict fluids and monitor sodium due to possible hyponatremia
What is Topical Thrombin used for?
Aid in hemostasis of oozing blood during surgery
What is the MOA of topical thrombin?
Converts fibrinogen to fibrin at the site of bleeding
What are the three types of antithrombotic agents?
- antiplatelet drugs
- anticoagulants
- fibrinolytic agents
What is the MOA of heparin?
Binds to anti-thrombin (III) and enhances the inactivation of factor Xa and thrombin
Do you need to adjust heparin for renal patients?
No, it is hepatically metabolized
What determines the anticoagulant activity of heparin?
The levels of heparin binding proteins in the plasma, weight and fixed doses are not predictors
What test do we use to monitor heparin levels?
aPTT or anti-factor Xa level
How do we monitor patients on heparin for bleeding?
Daily CBCs, ask about stool
What are the adverse effects of heparin?
Bleeding
Thrombocytopenia
Osteoporosis
Elevated LFTs
What are the CI for heparin?
HIT, allergy, active bleeding, hemophilia, thrombocytopenia, purpura, HTN
What is HIT?
Heparin induced thrombocytopenia
Kills platelets but also creates hypercoaguable state
More common in females
What is HIT caused by?
neoantigen is formed on platelet surface causing IgG antibody immune response
When does HIT occur?
5-10 days after heparin
any dose, any amount
How to treat HIT?
Stop heparin and mark as allergy in chart
Do not give platelets
Start non-heparin anticoagulant
After recovery continue on warfarin for 2-3 months if no thrombosis and 3-6 months if thrombosis occured
What is the brand name for low molecular weight heparin?
Lovenox
What is the MOA of Lovenox?
Enhances the inhibition of factor Xa by AT III
Does NOT inhibit thrombin
Can you use Lovenox in renal patients?
Dose adjust needed, do not use in ESRD
What monitoring should you do for Lovenox?
None really but can do factor Xa levels, aPTT should be normal
What are the adverse effects of Lovenox?
Bleeding, HIT, osteoporosis (all less so than heparin)
If you have a pregnant patient, would Lovenox or heparin be better?
Lovenox
What is the MOA of argatroban (Acova)?
selectively and reversibly binds to the active thrombin site of free and clot associated thrombin, thus inhibiting fibrin formation, activation of V, VIII, XIII, protein C and platelet aggregation
What are the indications for argatroba?
HIT
percutaneous coronary intervention
What is the MOA for bivaliruidin (Angiomax)?
reversibly binds to active thrombin site of free and clot associated thrombin
What are the indications for bivalirudin (Angiomax)?
percutaneous coronary intervention with a h/o HIT
What is the MOA for warfarin?
inhibits vitamin K oxide reductase complex subunit I, thus inhibiting factors II, VII, IX, and X
How long does it take warfarin to take effect?
5-7 days
When will a patient’s PT/INR change on warfarin?
36-72 hours
What pregnancy category is warfarin?
X DONT USE. But can be used while breastfeeding
What are the indications for warfarin?
prophylaxis and txt of thromboembolitic disorders/complications
What are the adverse effects of warfarin?
Bleeding
Necrosis/gangrene (seen without bridge)
Ethanol causes what effect on INR?
Acute increases but chronic decreases
Vitamin E causes what effect on INR?
increases
Cranberry juice causes what effect on INR?
increases
What is the MOA of Pradaxa?
direct thrombin inhibitor
What are the indications for Pradaxa?
stroke prevention in A-fib, DVT/PE (txt and prophylaxis)
Is there renal adjustment?
Yes
What medication reverses Pradaxa?
Praxbind
What is the MOA of Xarelto?
Oral Factor Xa inhibitor
What are the indications for Xarelto?
Stroke prevention in A-fib, PE/DVT txt and prophylaxis
Is there renal adjustment?
yes
What are the patient education points on Xarelto?
avoid in hepatic impairment
avoid grapefruit juice
avoid CYP3A4 inhibitors including fluroquinolones
What reverses Xarelto?
AndexXa
What is the MOA of Eliquis?
Reversible Oral Factor Xa inhibitor
What are the indications for Eliquis?
A-fib and DVT/PE
Is there a renal dose adjustment?
yes
What reverses Eliquis?
AndexXa
What is the MOA of edoxaban (Savaysa)?
Factor Xa inhibitor, selectively and reversibly blocks site of FXa without requiring a cofactor (antithrombin III) for activity
What are the indications for edoxaban (Savaysa)?
A-fib, PE/DVT
What condition needs a dose adjustment?
Reduce the dose for renal impairment and DO NOT USE with really good CrCl >95 mL/min
What is the antidote for edoxaban (Savaysa)?
No antidote
What is the MOA of Aspirin?
Irreversibly inhibits COX-1 and thus thromboxane A2
What are the indications for Aspirin?
Prevention of MI, vascular events, vascular disease
When should you take ASA in relation to NSAIDS?
60 minutes before or 8 hours after
What are common adverse events from ASA?
GI bleeding
Dyspepsia
Allergies
What is the MOA for Plavix?
Irreversibly binds and blocks ADP receptor (P2y12) inhibiting the ADP pathway of platelets. Requires metabolic activation (works 3-5 days)
Do you need a dose adjustment for Plavix?
Not renal or hepatic no, does require a loading dose
What drugs reduce plavix’s efficacy?
Omeprazole and esomeprazole
What is the MOA for prasugrel (Effient)
Irreversibly binds and blocks ADP receptor (P2y12) inhibiting the ADP pathway of platelets. Requires metabolic activation (works in 2-4 hours)
How long do the effects of prasugrel (Effient) last?
5-9 days
What are contraindications for prasugrel (Effient)?
h/o TIA and CVA
What is the MOA for ticlopidine (Ticlid)?
Irreversibly binds and blocks ADP receptor (P2y12) inhibiting the ADP pathway of platelets. Requires metabolic activation (works 3-5 days)
What monitoring must be done for ticlopidine (Ticlid)?
CBC with diff every 2 weeks for 3 months
What are the SE of ticlopidine (Ticlid)?
neutropenia, agranulocytosis, thrombotic thrombocytopenia purpura (TTP), and aplastic anemia
What is the MOA of Ticagrelor (Brilinta)?
Reversibly binds and blocks ADP receptor (P2y12) inhibiting the ADP pathway of platelets. Does NOT require metabolic activation (works in 1-3 hours)
How long do the effects of Ticagrelor (Brilinta) last?
3 days
What is the BBW for ticagrelor (Brilinta)?
Do not use with >100 mg ASA daily 2/2 decreased effectiveness
What is the MOA for cangrelor (Kengreal)?
Reversibly and non-competitively binds ADP receptor (P2y12) inhibiting the ADP pathway of platelets. Immediate onset of action within 3-5 minutes
What are the indications for cangrelor (Kengreal)?
percutaneous coronary intervention (cath lab only)
What is the MOA for TPA?
preferentially activates plasminogen that is bound to fibrin, which in theory confines fibrinolysis to the formed thrombus
What are the indications for TPA?
Ischemic stroke within 3 hours, PE with hemodynamic instability, STEMI, DVT, ascending thrombophlebitis
What is the MOA for steptokinase?
a protein produced by streptococci that combines with the proactivator plasminogen. The enzyme complex catalyzes the conversion of inactive plasminogen to active plasmin.
What are the indications for streptokinase?
PE, STEMI, DVT, ascending thrombophlebitis.
Do not use for ischemic stroke.
