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Saturday, 24 December 2011

Anticoagulation In Hemodialysis


Anticoagulation in Hemodialysis – MCQ Set 1 (Questions 1–10)

1. What is the most commonly used anticoagulant in routine hemodialysis?
A. Warfarin
B. Heparin
C. Citrate
D. Aspirin
Correct answer: B


2. The primary purpose of anticoagulation during hemodialysis is to:
A. Prevent anemia
B. Prevent clotting in the dialyzer and extracorporeal circuit
C. Increase blood pressure
D. Reduce infection risk
Correct answer: B


3. What is the usual route of heparin administration in hemodialysis?
A. Intramuscular
B. Oral
C. Intravenous
D. Subcutaneous
Correct answer: C


4. What is a common complication of excessive heparin use during dialysis?
A. Hypertension
B. Bleeding
C. Hyperkalemia
D. Itching
Correct answer: B


5. Which test is commonly used to monitor the effect of heparin?
A. Serum creatinine
B. PT/INR
C. Activated partial thromboplastin time (aPTT)
D. Fibrinogen
Correct answer: C


6. In patients at high risk of bleeding, what anticoagulation approach is often used?
A. Full-dose heparin
B. No anticoagulation or saline flush protocol
C. Double dose heparin
D. Aspirin
Correct answer: B


7. Which of the following is a low molecular weight heparin (LMWH) used in dialysis?
A. Enoxaparin
B. Warfarin
C. Aspirin
D. Sodium citrate
Correct answer: A


8. Heparin-induced thrombocytopenia (HIT) is a:
A. Bleeding disorder
B. Hemolytic reaction
C. Prothrombotic condition with low platelets
D. Sign of dialysis failure
Correct answer: C


9. What is the antidote for heparin overdose?
A. Vitamin K
B. Protamine sulfate
C. Fresh frozen plasma
D. Desmopressin
Correct answer: B


10. What is the function of regional citrate anticoagulation in dialysis?
A. It removes calcium from blood to prevent clotting
B. It enhances potassium removal
C. It increases phosphorus clearance
D. It disinfects the blood circuit
Correct answer: A


11. Which of the following patients is most likely to require a heparin-free dialysis?
A. Patient with diabetes
B. Patient with thrombocytosis
C. Post-operative patient with active bleeding
D. Patient on antihypertensive medications
Correct answer: C


12. What is the mechanism of action of heparin?
A. Inhibits platelet aggregation
B. Chelates calcium
C. Activates antithrombin III to inhibit thrombin and factor Xa
D. Destroys clotting factors
Correct answer: C


13. In low molecular weight heparin (LMWH) use, which test is best for monitoring?
A. aPTT
B. INR
C. Anti-factor Xa level
D. Hemoglobin
Correct answer: C


**14. Which anticoagulant is preferred for patients with heparin-induced thrombocytopenia (HIT)?
A. Low dose heparin
B. Aspirin
C. Argatroban
D. Warfarin
Correct answer: C


15. What is the risk of inadequate anticoagulation during dialysis?
A. Hypertension
B. Dialyzer clotting and circuit loss
C. Hypernatremia
D. Fluid overload
Correct answer: B


16. What is a major concern when using regional citrate anticoagulation?
A. Hypokalemia
B. Hyperglycemia
C. Hypocalcemia
D. Hyponatremia
Correct answer: C


17. When administering intermittent bolus heparin, the first dose is usually given:
A. At the end of dialysis
B. 30 minutes after dialysis begins
C. Before or at the start of dialysis
D. Only if clotting is seen
Correct answer: C


18. During heparin-free dialysis, what technique is used to prevent clotting?
A. Use of aspirin
B. Pulse saline flushes every 15–30 minutes
C. High calcium dialysate
D. Blood flow reduction
Correct answer: B


19. In which condition is systemic anticoagulation during dialysis generally contraindicated?
A. Stable angina
B. Recent hemorrhagic stroke
C. Hypertension
D. Diabetes mellitus
Correct answer: B


20. Why might LMWH be preferred over unfractionated heparin in some dialysis centers?
A. Cheaper and more easily available
B. Longer half-life and easier dosing
C. More reversible with protamine
D. Eliminates risk of thrombosis
Correct answer: B

21. What is the usual half-life of unfractionated heparin when used in dialysis?
A. 5 minutes
B. 30–60 minutes
C. 1–2 hours
D. 6–8 hours
Correct answer: C


22. When using LMWH in dialysis, a common complication compared to UFH is:
A. More allergic reactions
B. Higher incidence of thrombocytopenia
C. Increased bleeding risk due to longer half-life
D. Lower cost
Correct answer: C


23. Which of the following anticoagulation methods is most appropriate in a patient with severe liver failure on dialysis?
A. Warfarin
B. Unfractionated heparin
C. Citrate anticoagulation
D. LMWH
Correct answer: C


24. What is the primary site of metabolism for low molecular weight heparin?
A. Liver
B. Kidney
C. Spleen
D. Bone marrow
Correct answer: B


25. Which of the following is a contraindication to regional citrate anticoagulation?
A. Hypocalcemia
B. Sepsis
C. Hypertension
D. Diabetes
Correct answer: A


26. Protamine sulfate reverses which of the following?
A. Warfarin
B. Citrate
C. Unfractionated heparin
D. Dabigatran
Correct answer: C


27. Which anticoagulant does not require routine coagulation monitoring in stable patients?
A. Unfractionated heparin
B. LMWH
C. Warfarin
D. Argatroban
Correct answer: B


28. What is the key reason for choosing heparin-free dialysis in a patient with recent gastrointestinal bleeding?
A. Improve blood pressure
B. Reduce sodium retention
C. Minimize bleeding risk
D. Increase urea clearance
Correct answer: C


29. If clotting is observed in the venous chamber during dialysis, what should be done FIRST?
A. Start saline flushes
B. Increase heparin dose immediately
C. Stop dialysis immediately
D. Re-prime the dialyzer
Correct answer: A


30. Warfarin is generally avoided in chronic hemodialysis patients because:
A. It causes hypokalemia
B. It requires monthly injections
C. It has high bleeding risk and is hard to control in ESRD
D. It reduces dialysis efficacy
Correct answer: C


31. Which patient may need a reduced dose of heparin during dialysis?
A. Obese patient
B. Patient with active infection
C. Elderly patient with a history of GI bleeding
D. Diabetic with well-controlled sugars
Correct answer: C


32. During dialysis, if the arterial pressure alarm is high and clotting is suspected in the line, what is the immediate action?
A. Increase blood flow rate
B. Flush with saline and assess for clot
C. Decrease dialysate flow
D. Ignore if patient is stable
Correct answer: B


33. Which of the following anticoagulation methods is most commonly used in intermittent hemodialysis in outpatient centers?
A. Warfarin
B. LMWH
C. Heparin bolus followed by maintenance infusion
D. Argatroban
Correct answer: C


34. Regional citrate anticoagulation works by binding to which electrolyte?
A. Magnesium
B. Potassium
C. Calcium
D. Phosphate
Correct answer: C


35. When is saline flush protocol preferred over anticoagulation during dialysis?
A. In pediatric patients
B. In patients with severe anemia
C. In patients with high bleeding risk
D. In those on immunosuppressants
Correct answer: C


36. What is a limitation of using LMWH in hemodialysis?
A. Requires frequent INR monitoring
B. Not reversible with protamine sulfate
C. Cannot be used in diabetic patients
D. Causes hypertension
Correct answer: B


37. What is the main advantage of LMWH over UFH in hemodialysis?
A. Shorter half-life
B. Lower cost
C. Simplified dosing with fewer monitoring requirements
D. Safe in all liver diseases
Correct answer: C


38. Which of the following is a sign of underdosing anticoagulation during dialysis?
A. Nosebleeds
B. Recurrent clotting in the circuit
C. Hypotension
D. Hematuria
Correct answer: B


39. Which anticoagulant is sometimes used in patients with heparin allergy or HIT during dialysis?
A. Enoxaparin
B. Aspirin
C. Argatroban
D. Clopidogrel
Correct answer: C


40. What lab finding is most concerning if a patient on heparin develops sudden thrombocytopenia?
A. Hemoglobin drop
B. Platelets <50,000 with thrombosis
C. Elevated creatinine
D. Prolonged PT
Correct answer: B


41. Which of the following is a non-heparin anticoagulant suitable for dialysis in patients with HIT?
A. Fondaparinux
B. Argatroban
C. Warfarin
D. Tranexamic acid
Correct answer: B


42. Why is warfarin generally not initiated solely for anticoagulation during hemodialysis?
A. It causes hyperkalemia
B. It increases calcium levels
C. It does not act quickly enough and is hard to manage in ESRD
D. It increases urea clearance
Correct answer: C


43. A patient undergoing dialysis complains of sudden back pain and hypotension. What complication related to anticoagulation should you consider?
A. Hyperphosphatemia
B. Dialysis disequilibrium
C. Retroperitoneal bleed
D. Clotting in dialyzer
Correct answer: C


44. What is the most accurate test to detect early HIT (Heparin-Induced Thrombocytopenia)?
A. PT
B. aPTT
C. Platelet factor 4 antibody (ELISA)
D. Bleeding time
Correct answer: C


45. In hemodialysis, what is the target activated clotting time (ACT) during heparin use?
A. 60–90 seconds
B. 120–180 seconds
C. 180–220 seconds
D. >300 seconds
Correct answer: B


46. What is a benefit of regional citrate anticoagulation over systemic heparin?
A. Easy to administer
B. Eliminates need for calcium monitoring
C. Less bleeding risk
D. Shorter dialysis time
Correct answer: C


47. What is the function of calcium infusion during citrate anticoagulation?
A. Prevent clotting in the dialyzer
B. Maintain systemic calcium levels
C. Reduce potassium
D. Promote citrate clearance
Correct answer: B


48. Which medication is not used for anticoagulation in dialysis patients?
A. Enoxaparin
B. Argatroban
C. Clopidogrel
D. Unfractionated heparin
Correct answer: C


49. Heparin-induced thrombocytopenia typically occurs within how many days of starting heparin?
A. 1–2 days
B. 3–5 days
C. 5–10 days
D. 14–21 days
Correct answer: C


50. Which of the following indicates the need for immediate discontinuation of anticoagulation during dialysis?
A. Mild bruising
B. Elevated creatinine
C. Sudden drop in blood pressure with active bleeding
D. Slight prolongation of aPTT
Correct answer: C



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