Exam 3: Blood Disorders Flashcards
What is the most common hereditary bleeding disorder?
vWF disorder (platelet adhesion dysfunction)
What are the S/S of vWF disorder?
Easy bruising
epistaxis
menorrhagia (menstrual bleeding)
patient usually unaware until questionnaire/surgery
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
- Factor VIII
- cryo
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- 0.8 mcg/kg in 50 mL over 10-15 mins (Do not bolus)
What is the onset & duration of DDAVP?
- Onset: 30mins (max effect)
- Duration: 6-8hrs
What are the side effects of DDAVP?
- HA
- Stupor
- hypotension
- tachycardia
- hyponatremia (d/t retention of water, pt needs to be on fluid restriction)
- water intoxication (excessive water retention… patient needs to be on water restriction for 4-6 hours after administration)
What is the major side effect of DDAVP?
Hyponatremia
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 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)
comes in 2-10 pooled units… multiple donors like platelets
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 and during surgery
What blood product poses an increase risk for infection? Why?
Which blood product doesn’t have increased risk of infection?
- Cryoprecipitate
- Not sent for viral attenuation
- F VIII undergoes viral attenuation
Pts with coagulopathies undergoing neuraxial anesthesia are at increased risk for what?
- epidural Hematoma
- paralysis
- 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)
- avoid spinals
How does heparin work?
- Heparin activates antithrombin III
- AT-III will inhibit thrombin
- negatively charged
thrombin needed to convert fibrinogen -> fibrin
What labs are monitored with heparin?
PTT &/or ACT
What is the mechanism of action of Coumadin?
Interferes with hepatic synthesis of vitamin K-dependent factors: II, VII, IX, X
Which factors are vitamin-K dependent?
II, VII, IX & X
What is the onset for Vitamin K?
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
- Causes clot dissolution
How do tranexamic acid (TXA), aminocaproic acid, and aprotinin work?
Inhibit conversion of plasminogen to plasmin
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 (thrombin time)
- ↑ fibrin degradation products
When is antifibrinolytic therapy given to someone in DIC?
Trick question, it shouldn’t. Can lead to catastrophic thrombotic complications
TX: blood components to replace coagulation factors and platelets
What is factor V?
- Protein for normal clotting
When enough fibrin has been made, Activated protein C inactivates factor V thus stopping clot growth (negative feedback)
What is Factor V Leiden deficiency?
Genetic mutation of Factor 5
- Activated protein C can’t stop factor V Leiden from making more fibrin
Clotting disorder
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?
1 LMWH (lovenox)
- warfarin
- unfractionated heparin
What is the hallmark sign of HIT?
Plt count <100,000
Autoimmune 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 (arterial and venous)
What is heparin replaced with when HIT is diagnosed?
direct-thrombin inhibitors
- Argatroban
- Bivalirudin
- Lepirudin
What is Fonaparinaux & when is it used?
A synthetic Factor Xa inhibitor
- used to treat VTE in HIT
What timing should DDAVP be given?
60 minutes before surgery
What type of anesthesia to use for increased risk bleeding disorders?
general anesthesia
What’s a normal ACT level?
Systemic anticoagulant goal?
150 seconds
systemic anticoagulation goal 350-400
What do you give if Heparin not increasing ACT?
FFP
provides antithrombin
what reverses Heparin?
Protamine
positively charged polypeptide forming a stable complex neutralizing heparin
Sign of toxicity of TXA?
color blindness
Dose of TXA in adults and kids?
Adults: 1-2g IVP or in 50 mL bag
* 2g bolus then additional if needed
Kids: 15 mg/kg
What 2 reason is TXA commonly used for?
menorrhagia
recurrent epistaxis
What’s used to score sepsis/ DIC?
APACHE score
What is DIC?
systemic activation of the coagulation system simultaneously leading to thrombin formation and exhaustion of platelets and coagulation factors
What are 2 prothrombotic disorders?
HIT
factor V Leiden
What immune complexes is HIT mediated by?
IgG antibody, platelet factor 4 (PF4), and heparin
*usually clear from the circulation within 3 months
Plateletes developing HIT during Heparin therapy should experience substanantially increased risk for thrombosis is what percentage?
30-75%
