A patient is scheduled to have a thyroidectomy. Which medication does the nurse anticipate the Doctor will prescribe to decrease the size and vascularity of the thyroid gland before surgery?

1. A

   Vasopressin

2. B

   Propylthiouracil

3. C

   Potassium iodide

4. D

   Levothyroxine

Appeared in: ISRO 2024

Explanation

• Potassium iodide is administered for 10-14 days before a thyroidectomy to prepare the gland for surgery.
• Its primary effect is to inhibit the release of thyroid hormones, which makes the gland firmer and significantly reduces its size and vascularity (blood supply).
• This reduction in blood flow is critical for minimizing the risk of intraoperative hemorrhage, making the surgery safer and technically easier for the surgeon.

Why Other Options Were Wrong

• Option A: Vasopressin is an antidiuretic hormone (ADH) that regulates water balance in the body by acting on the kidneys.
• Option B: Propylthiouracil (PTU) is an antithyroid drug that blocks the synthesis of new thyroid hormones. While it is used pre-operatively, its goal is to achieve a euthyroid state, not to reduce vascularity.
• Option D: Levothyroxine is a synthetic thyroid hormone (T4) used for hormone replacement therapy.

Related Visual

Clinical Relevance

• Nursing practice connection: Safe nursing care depends on performing Preoperative pharmacological management for thyroidectomy in the correct sequence, documenting the action clearly, and monitoring for the expected response.
• The primary nursing goal in preoperative thyroid care is patient safety, which includes minimizing the risk of surgical complications like hemorrhage. Understanding the role of potassium iodide is key to this.
• Nurses are responsible for administering potassium iodide correctly (diluted, with a straw) and educating the patient on its purpose and potential side effects.
• Monitoring for signs of iodism (metallic taste, mouth sores, rash) is a critical nursing assessment to ensure the patient's safety during the 10-14 day preoperative period.

How to Approach the Question

• First, identify the specific goal stated in the question: to 'decrease the size and vascularity' of the thyroid gland before surgery.
• Next, analyze the primary mechanism of action for each medication option provided.
• Eliminate options with unrelated functions. Vasopressin affects water balance, and Levothyroxine is a hormone replacement for hypothyroidism; neither is used for preoperative hyperthyroid preparation.
• Differentiate between the remaining two antithyroid medications. Propylthiouracil's main role is to stop hormone production to achieve a normal metabolic state (euthyroidism).
• Recall or deduce that Potassium iodide has a unique, short-term effect of making the gland less vascular and smaller, which directly addresses the surgical safety concern mentioned in the question.
• Therefore, select Potassium iodide as the medication that specifically targets reducing gland size and blood flow for surgery.

Concept Tested & Keywords

• Concept Tested: Preoperative pharmacological management for thyroidectomy.
• Stem keywords: thyroidectomy, medication, decrease the size, vascularity, before surgery
• Lead-in keywords: Which medication
• Clinical cues: Patient scheduled for thyroidectomy, indicating a need for preoperative preparation.
• Negative lead-in flag: false

Question ID

QIaTqSEBGWILSOlRPC16N

Copy ID

Reference Book

E6 Medicine Davidson Principles Practice 24e p. 665-667

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 4 p. 22-24