Patient with pulmonary embolism is given heparin I/V as an anti-coagulant and anti-thrombotic agent to?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Edition 3

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Explanation

The primary goal of heparin therapy in pulmonary embolism (PE) is to prevent the existing clot from enlarging and to stop new clots from forming.
Heparin achieves this by potentiating antithrombin III, which inactivates key clotting factors like thrombin (IIa) and factor Xa.
This action interrupts the clotting cascade, thereby prolonging the time it takes for blood to clot (measured by aPTT) and preventing the conversion of fibrinogen to fibrin.
It is crucial to understand that heparin does not dissolve the existing clot; it only prevents its progression and recurrence.

Option A: Prothrombin time (PT) is the laboratory test used to monitor warfarin therapy, not heparin. The correct test for unfractionated heparin is the activated Partial Thromboplastin Time (aPTT).
Option B: This statement is too general. While heparin does interrupt the coagulation mechanism, it doesn't describe the specific therapeutic goal. The best answer specifies the clinical outcome: preventing further clot formation.
Option C: This describes the action of protamine sulfate, which is the antidote used to reverse the effects of heparin in cases of overdose or severe bleeding. It is not the therapeutic action of heparin itself.

Clinical Relevance

Nursing practice connection: Use the key finding related to Pharmacology: Mechanism of Action of Heparin to guide bedside assessment, documentation, and the next nursing action.
For a nurse administering IV heparin, the priority is monitoring for therapeutic effectiveness (via aPTT) and for the major side effect: bleeding. This requires vigilant patient assessment and adherence to bleeding precautions.
Understanding the difference in monitoring between heparin (aPTT) and warfarin (PT/INR) is a critical patient safety issue to prevent medication errors.
What if? If the patient's aPTT comes back significantly above the therapeutic range (e.g., greater than 100 seconds), the nurse's first action is to stop the heparin infusion and immediately notify the healthcare provider, as the patient is at high risk for hemorrhage.

How to Approach the Question

First, identify the core subject of the question: the purpose of heparin in a patient with pulmonary embolism.
Analyze the keywords: 'heparin', 'anti-coagulant', 'pulmonary embolism'. This tells you the question is about the therapeutic goal of this specific drug in this specific condition.
Evaluate each option for its accuracy and specificity. Option A is factually incorrect regarding the monitoring test. Option C describes an antidote, not the drug's action. Option B is true but too general.
Option D provides the most precise and complete description of why heparin is used in this clinical scenario: to prevent the clot from getting worse and to stop new clots from forming.
Select the option that best describes the specific clinical objective of the therapy.

Concept Tested & Keywords

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