Which of the following drug is used to prevent blood clotting during hemodialysis procedure?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2018

Pharmacology

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2018

Explanation

Heparin is the standard anticoagulant used to prevent blood from clotting in the dialysis machine's circuit.
It works by activating antithrombin III, which in turn blocks key clotting factors (thrombin and Factor Xa), preventing the formation of a fibrin clot.
Its rapid onset of action and short half-life make it ideal for the duration of a hemodialysis session, as its effects can be quickly initiated and reversed.
Heparin is specifically indicated for preventing clotting in extracorporeal circuits, such as during dialysis or open-heart surgery.

Option A: Aspirin is an antiplatelet drug, not a primary anticoagulant. It inhibits platelet aggregation but is not potent enough to prevent the large-scale clot formation that can occur in the hemodialysis circuit.
Option C: Protamine (specifically Protamine Sulfate) has the opposite effect. It is a heparin antagonist, meaning it is administered to reverse the anticoagulant effects of heparin, often in cases of overdose or post-procedure.
Option D: Coumadin (warfarin) is a long-acting oral anticoagulant. Its onset of action takes several days, making it unsuitable for the acute, short-term anticoagulation required for a single hemodialysis session.

Clinical Relevance

Nursing practice connection: Knowing Anticoagulation in Hemodialysis helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Preventing clotting in the dialysis circuit is critical for patient safety and treatment efficacy. Clotting can obstruct blood flow, reduce the effectiveness of dialysis, and necessitate the premature termination of the session.
Nurses must meticulously monitor the heparin infusion rate and the patient's clotting times (e.g., ACT, aPTT) to balance the prevention of clots against the risk of bleeding.
What if? If a patient has a history of Heparin-Induced Thrombocytopenia (HIT), heparin is contraindicated. In this case, an alternative anticoagulant such as argatroban or regional citrate anticoagulation would be used for the hemodialysis procedure.

How to Approach the Question

First, identify the core of the question: it asks for a drug to prevent clotting specifically during hemodialysis.
Recall the purpose of hemodialysis: blood is circulated outside the body through a machine. This extracorporeal circulation activates the clotting cascade.
Evaluate each option based on its primary mechanism and use case.
Aspirin is antiplatelet, used for long-term prevention, not acute procedures.
Heparin is a fast-acting anticoagulant, a classic choice for procedures like dialysis.
Protamine is a reversal agent for heparin, so it promotes clotting.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 2 pp. 111-113, 127-129

E6 Physiology Essentials Sembulingam 10e Part 1 p. 140-142