To enhance the percutaneous absorption of nitroglycerin patches, it would be MOST important for the nurse to select a site that is which of the following?

Appeared in: NORCET -4 , 2023

Explanation

A non-hairy area is the most critical site characteristic because it ensures the transdermal patch can adhere completely and flatly against the skin.
Hair creates a physical barrier, preventing full contact between the patch and the epidermis, which significantly reduces the surface area available for drug absorption.
Optimal percutaneous absorption relies on the medication diffusing through the skin layers into the rich capillary network below; this process is only effective with direct, uninterrupted skin contact.
Commonly recommended sites include the upper chest, back, abdomen, or upper arms, specifically choosing areas with minimal hair.

Option A: Nitroglycerin acts systemically after being absorbed into the bloodstream. Its therapeutic effect on the coronary arteries does not depend on proximity to the heart.
Option C: Transdermal absorption occurs through the epidermis and dermis into the subcutaneous capillaries, not directly into muscle tissue. While muscle has good blood flow, the drug must first pass through the skin.
Option D: Bony prominences (like the shoulder, hip, or shin) provide an irregular surface that compromises patch adhesion. These areas are also prone to friction, which can dislodge the patch.

Visual 1: Diagram: Illustrating correct application sites for a transdermal patch (e.g., upper chest, back, upper arm, abdomen) and highlighting areas to avoid (hairy areas, skin folds, bony prominences, irritated skin).

Clinical Relevance

Nursing practice connection: Knowing Principles of transdermal medication administration helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Proper site selection is a critical nursing responsibility to ensure therapeutic drug levels are achieved. Incorrect application can lead to underdosing and treatment failure, such as continued angina pain.
Patient education is vital. The nurse must teach the patient and family how to rotate sites, what to look for (skin irritation), and why hairy areas should be avoided to ensure medication safety and efficacy at home.
What if the patient has a very hairy chest? The nurse should instruct the patient to find an alternative, less hairy site (like the upper back or upper arm) or to clip the hair with scissors. Shaving is not recommended as it can cause micro-abrasions, which can alter drug absorption and increase skin irritation.

How to Approach the Question

First, identify the core of the question: what is the MOST important factor for 'percutaneous absorption' of a patch?
Recall that 'percutaneous' means 'through the skin'. The primary goal is to get the medication from the patch, through the skin, and into the bloodstream.
Analyze what would best facilitate this transfer. The patch must stick securely and have maximum contact with the skin surface.
Evaluate each option based on this principle. Does being 'near the heart' affect skin contact? No. Does 'muscular' matter for a skin patch? No. Does a 'bony prominence' help it stick? No, it hinders it.
Consider 'non-hairy area'. Hair would physically block the patch from sticking flat against the skin, clearly reducing contact and absorption.
Conclude that the absence of hair is the most critical factor among the choices for ensuring the patch works as intended.

Concept Tested & Keywords

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Practise the full NORCET -4 , 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.