Blood Disorders Flashcards
Exam 3
What are the S/S of vWF disorder?
Easy bruising
epistaxis
menorrhagia
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
- 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
- Duration: 6-8hrs
What are side effects of DDAVP?
- HA
- Stupor
- hypotension
- tachycardia
- hyponatremia
- water intoxication (excessive water retention)
What is the most major side effect of DDAVP?
Hyponatremia
What are the S/Sx of a Na level of 120? What would you expect to see on EKG?
Sx: confusion and restlessness
EKG: maybe some widening of the QRS
What are the S/Sx of a Na level of 110? What would you expect to see on EKG?
Sx: coma or seizures
EKG: vtach and vfib
What are the S/Sx of a Na level of 115? What would you expect to see on EKG?
Sx: somnolence and nausea
EKG: widened QRS and ST elevation
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)
How is Factor VIII concentrate made? What clotting factors does it contain?
Pool of plasma from a large number of donors. It contains factor VIII and vWF.
When is Factor VIII given?
Preop or intraop
When should DDAVP be given prior to surgery?
30-60mins before Sx
What blood product poses an increase risk for infection? Why?
- Cryoprecipitate
- Not sent for viral attenuation (Factor VIII is)
Pts with coagulopathies undergoing neuraxial anesthesia are at increased risk for what?
- Hematoma
- Nerve compression
What are the anesthesia considerations for someone with vWF deficiency?
- Avoid trauma (particularly airway)
- avoid IM sticks
- avoid arterial lines (if feasible)
- avoid spinals
What is acquired bleeding?
bleeding from taking certain medications like Heparin, Warfarin, fibrinolytics and antiplatelets.
What is Heparin?
a negatively charged CHO with glucuronic acid residues
How does heparin work?
- Thrombin inhibition
- Antithrombin III activation
There is a large population of people with antithrombin III deficiency… what can you use to treat this?
FFP
What is used to reverse Heparin?
Protamine, a positive polypeptide that neutralizes Heparin
What labs are monitored with heparin?
PTT &/or ACT
What is the target ACT for cardiac bypass surgery? ACT goal to pull a sheath?
Cardiac bypass: 350-400
Pull sheath: <150
What are three benefits to LMWH’s?
- More effective VTE prevention than UFH
- Fewer effects on platelet function and reduced risk of HIT
- LMWH does not need to be monitored as closely- more predictable pharmacokinetics
What is the mechanism of action of Coumadin?
Inhibition of vitamin K-dependent factors.
Which factors are vitamin-K dependent?
II, VII, IX & X
What is the onset for Vitamin K administration for Coumadin reversal?
6-8hrs
What drugs/products can be given to reverse coumadin faster than Vit K?
- Prothrombin complex concentrates
- Factor VIIa
- FFP
-cryo
What is the mechanism of action for fibrinolytics (UK, streptokinase & tPA)?
Convert plasminogen to plasmin, which cleaves fibrin causing clot dissolution
How do tranexamic acid (TXA) and aminocaproic acid work?
Inhibit conversion of plasminogen to plasmin
What are the pediatric and adult doses for TXA and a weird side effect?
Peds: 15mg/kg
Adult: 1-2 g IV
SE: loss of color vision
What is the best way to treat DIC?
Treat the underlying cause and give blood transfusions to replete coagulation factors and platelets consumed
What are some things that can cause DIC?
-sepsis
-trauma
-amniotic fluid embolus
-malignancy
-incompatible blood transfusions
What will labs show for someone in DIC?
- ↓Platelet count
- 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 are two prothrombic disorders talked about in class?
- HIT
- Factor V Leiden deficiency
What is factor V Leiden?
- Protein for clotting.
Activated protein C inactivates factor V thus stopping clot growth.
What is Factor V Leiden deficiency?
Genetic mutation of factor V (Factor V Leiden) is resistant to activated protein C which cannot stop FVL from making more fibrin, thus excessive fibrin leads to clot formation.
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 abortions
What anticoagulant medications could someone with Factor V Leiden be put on?
- Warfarin
- LMWH & unfractionated heparin
What is the hallmark sign of HIT and when does it usually develop?
Plt count <100,000
develops 5-14 days after initial Heparin therapy
HIT results in ____ activation and potential____?
platelet; thrombosis (absolute risk 30-75%)
Evidence suggests that HIT is mediated by__________.
immune complexes ( IgG AB, platelet Factor 4, and heparin)
What is heparin replaced with when HIT is diagnosed?
Agratroban or bivalirudin (direct-thrombin inhibitors)
What is Fondaparinux & when is it used?
- A synthetic Factor Xa inhibitor
- used to treat VTE in HIT
