Blood Disorders (Exam III) Flashcards
What is the number 1 most common bleeding disorder?
vWF disorder (platelet adhesion dysfunction)
What are the S/S of vWF disorder?
Easy bruising
epistaxis
menorrhagia (menstrual bleeding)
What would lab values be for someone with vWF deficiency?
- Normal PT & aPTT
- Bleeding time is prolonged
What are the treatments for vWF deficiency?
- Desmopressin (Vaso)
- Cryoprecipitate
- Factor VIII
How does DDAVP work in regards to treatment of von Willebrand deficiency??
Stimulates vWF release from endothelial cells
What is the dose for DDAVP?
0.3 mcg/kg in 50 mL over 15-20 mins (Do not bolus)
What is the onset & duration of DDAVP?
- Onset: 30mins (max effect)
- Duration: 6-8hrs
Don’t bolus DDAVP; drip slowly.
What are the side effects of DDAVP?
- HA
- Stupor
- hypotension (if given quickly)
- tachycardia
- hyponatremia (d/t retention of water, pt needs to be on strict fluid restriction- no toilet water!)
- water intoxication(excessive water retention)
What is the major side effect of DDAVP?
Hyponatremia due to water retention (dilutional)
Na+ 120: Confusion, restlessness, wide QRS
Na+ 115: Somnolence, nausea, elevated ST, wide QRS
Na+ 110 Seizure, coma, V-tach, V-fib
Someone that gets DDAVP needs to be on what?
Fluid restriction 4-6hrs before & after DDAVP
What blood product can be utilized for vWF disease if the patient is unresponsive to DDAVP?
Cryoprecipitate
1 unit of Cryo raises the ____ level by ___?
Fibrinogen by 50 mg/dL
What is a potential risk factor with cryoprecipitate?
Increased risk of infection (not submitted to viral attenuation) and it is pooled from many donors
What is Factor VIII concentrate made of?
Pool of plasma from a large number of donors.
Contains Factor VIII and vWF
When is Factor VIII given?
Preop or intraop
What blood product poses an increase risk for infection? Why?
- Cryoprecipitate
- Not sent for viral attenuation
Pts with coagulopathies undergoing neuraxial anesthesia are at increased risk for what?
- Dural Hematoma
- Nerve compression
What are the anesthesia considerations for someone with vWF deficiency?
- Avoid trauma (Get the best intubator performing DL)
- avoid IM sticks (Will cause localized tissue trauma)
- avoid arterial lines (if feasible) not the patient for you to practice A-lines on
- avoid spinals- the spine is not easy to hold compression on if the patient is bleeding
How does heparin work?
- Heparin activates antithrombin III
- AT-III then inhibits thrombin to stop clots from ever forming
What labs are monitored with heparin?
PTT &/or ACT
What is the mechanism of action of Coumadin?
Inhibition of vitamin K-dependent factors.
That is why vitamin-k is the antidote for Warfarin
Which factors are vitamin-K dependent?
II, VII, IX & X
(2, 7, 9, 10)
What is the onset for Vitamin K?
6-8hrs
So don’t think it is a quick reversal!
What drugs/products can be given to reverse coumadin faster than Vit K?
- Prothrombin complex concentrates
- Factor VIIa
- FFP
What is the mechanism of action for fibrinolytics (UK, streptokinase & tPA)?
Convert plasminogen to plasmin, which cleaves fibrin (clot buster)
How do tranexamic acid (TXA) and aminocaproic acid work?
Inhibit conversion of plasminogen to plasmin
Plasmin that is never formed cannot break up the clot, so it is PRO-CLOT
What is the best way to treat DIC?
Treat the underlying cause
What will labs show for someone in DIC?
- ↓PLTs
- Prolonged PT, PTT & TT.
- ↑ fibrin degradation products
When is antifibrinolytic therapy given to someone in DIC?
Trick question, it shouldn’t. Can lead to catastrophic thrombotic complications
What is factor V Leiden?
- Protein for clotting.
Activated protein C inactivates factor V thus stopping clot growth (negative feedback).
What is Factor V Leiden deficiency?
Genetic mutation of Factor V Leiden where Activated protein C cannot complete the negative feedback loop of clot promation thus excessive fibrin/clots are created.
What does Activated Protein C do?
Inactivates factor V when enough fibrin has been made.
Who is usually tested for Factor V Leiden?
Pregnant women. Especially ones with unexplained late stage miscarriages
What anticoagulant medications could a pregnant woman with Factor V Leiden be put on?
- LMWH
- For individuals with severe Factor V, they will be placed on Coumadin
What is the hallmark sign of HIT?
Plt count <100,000
Thrombocytopenia occurs 5-14 days after initial heparin therapy and affects 5% of patients exposed to unfractionated heparin and rare cases LMWH.
HIT results in ____ activation and potential____?
platelet; thrombosis/microclots
What is heparin replaced with when HIT is diagnosed and why?
Argatroban or bivalirudin (direct-thrombin inhibitors)
Bc they still need anti-clot meds for whatever they were on the heparin for in the first place
What is Fondaparinaux & when is it used?
- A synthetic Factor Xa inhibitor
- used to treat VTE in HIT
