Blood Disorders Flashcards
1
Q
- What is the most common hereditary bleeding disorder?
A
Von Willebrand Factor (vWF) Disorder.
2
Q
- What are clinical features of vWF disorder?
A
- Easy bruising - Recurrent epistaxis - Menorrhagia - Patients often unaware until surgery or detailed history
3
Q
- What role does vWF play in hemostasis?
A
Critical for platelet adherence and adhesion.
4
Q
- What are the types of inherited von Willebrand Disease?
A
- Type 1: Most mild - Type 2 (subtypes like 2N): Moderate - Type 3: Most severe, rare
5
Q
- How is vWF disease diagnosed in labs?
A
- PT and aPTT usually normal - Bleeding Time (BT) is prolonged - Hematologist typically analyzes labs
6
Q
- What is the primary treatment for vWF disease?
A
- Desmopressin (DDAVP) - Cryoprecipitate - Factor VIII concentrate (for severe or unresponsive cases)
7
Q
- How does DDAVP work?
A
It is a synthetic vasopressin that stimulates the release of vWF from endothelial cells.
8
Q
- What is the IV dose and onset of DDAVP?
A
- 0.3 mcg/kg in 50 mL NS over 15–20 mins - Max effect: 30 mins - Duration: 6–8 hours
9
Q
- What are side effects of DDAVP?
A
- Headache - Flushing (rubor) - Hypotension - Tachycardia - Hyponatremia and water intoxication → seizures, death
10
Q
- How can hyponatremia be prevented with DDAVP?
A
Restrict water intake (oral or IV) for 4–6 hours post-dose Monitor sodium levels closely
11
Q
- What happens if sodium drops dangerously low?
A
- Headache - Confusion - Tachycardia - Seizures - Death
12
Q
- What electrolyte levels are commonly tested with DDAVP use?
A
- Sodium - (Also important: Potassium, Magnesium for general board relevance)
13
Q
- What is cryoprecipitate and when is it used?
A
- Used if DDAVP fails - Raises fibrinogen by 50 mg/dL per unit - Not virus-inactivated = ↑ infection risk - Usually pooled from 2–10 donors = ↑ reaction risk
14
Q
- What does Factor VIII concentrate contain?
A
- Factor VIII - Often includes vWF - Viral attenuation reduces infection risk
15
Q
- When is Factor VIII concentrate given?
A
- Preoperatively - During surgery if bleeding occurs
16
Q
- What anesthesia considerations are key for vWF patients?
A
- Get hematology consult pre-op - Infuse DDAVP 60 mins before incision - Confirm bleeding time and Factor VIII levels pre-surgery
17
Q
- Why is general anesthesia preferred in coagulopathic patients?
A
To avoid risk of epidural hematomas from neuraxial blocks.
18
Q
- What are examples of trauma to avoid in anesthesia for these patients?
A
- Traumatic intubation → airway hematomas - Arterial punctures (esp. femoral) - IM injections - Vascular access by inexperienced providers
19
Q
- How to reduce vascular trauma risk?
A
- Use ultrasound-guidance for arterial/central lines - Consider non-invasive CO monitors (e.g., ClearSight, Cheetah)
20
Q
- What is the most common acquired cause of bleeding?
A
Heparin (UFH and LMWH)
21
Q
- How does Heparin work?
A
Inhibits thrombin by activating antithrombin III
22
Q
- How is Heparin monitored?
A
- PTT - ACT (intraoperatively)
23
Q
- What reverses Heparin?
A
Protamine sulfate
24
Q
- What’s a major problem with Heparin?
A
May not work if patient has antithrombin III deficiency
25
25. How to treat antithrombin III deficiency?
Give FFP to restore antithrombin III
26
26. What coag factors are Vitamin K–dependent?
Factors II, VII, IX, X
27
27. How to reverse Coumadin quickly?
- Prothrombin complex concentrates (PCCs) - Recombinant factor VIIa - FFP (*Vitamin K alone takes 6–8 hours*)
28
28. What are fibrinolytic drugs and how do they work?
- tPA, streptokinase, urokinase - Convert plasminogen → plasmin → breaks fibrin → dissolves clots
29
29. What are antifibrinolytics?
- Tranexamic acid (TXA) - ε–aminocaproic acid (Amicar) - Inhibit plasminogen → plasmin
30
30. What are TXA side effects?
- Color vision loss (toxicity) - Contraindicated in patients with pre-existing color vision deficiency
31
31. What are TXA dosing options?
- Adults: 1–2 g IV (push or over 50 mL) - Peds: 15 mg/kg - Can repeat dosing as needed
32
32. What is DIC?
Disseminated Intravascular Coagulation = simultaneous clotting and bleeding
33
33. What causes DIC?
- Sepsis - Trauma - Amniotic fluid embolus - Cancer - Incompatible transfusions
34
34. DIC lab findings?
- ↓ Platelets - ↑ PT, PTT, TT - ↑ Fibrin degradation products (FDPs)
35
35. How is DIC treated?
- Address underlying cause - Replace with blood products (FFP, PLTs) - Avoid antifibrinolytics
36
36. What is Factor V Leiden?
Genetic mutation causing resistance to activated protein C, leading to excessive clotting
37
37. When is Factor V Leiden often first seen?
- During pregnancy - Recurrent miscarriages or late fetal losses
38
38. How is Factor V Leiden managed?
- Anticoagulation (LMWH, warfarin, UFH) - Often general anesthesia if pregnant + anticoagulated
39
39. What is HIT (Heparin-Induced Thrombocytopenia)?
Autoimmune reaction to heparin-PF4 complex → ↓ PLTs + ↑ thrombosis risk
40
40. When does HIT typically occur?
5–14 days after starting heparin (UFH > LMWH)
41
41. What’s the platelet count in HIT?
< 100,000
42
42. What is the treatment for HIT?
- Stop all heparin sources (flushes, IVs, bonded catheters) - Use non-heparin anticoagulants: argatroban, bivalirudin, fondaparinux
43
43. Should patients with HIT ever get heparin again?
No — future exposure may trigger severe thrombosis
