Most common complication of radio iodine therapy for thyrotoxicosis is?

HPSSSB Staff Nurse - 2016

Medical & Surgical Nursing

Medium

Appeared in: HPSSSB Staff Nurse - 2016

Explanation

Radioactive iodine (¹³¹I) therapy works by concentrating in the thyroid and destroying the cells that produce thyroid hormone.
This destruction of thyroid tissue is progressive and extensive, leading to a permanent inability of the gland to produce sufficient hormones.
Consequently, hypothyroidism is the most frequent long-term outcome, occurring in up to 80% of patients, and is often considered an expected result of successful treatment rather than a side effect.
Patients will require lifelong thyroid hormone replacement (levothyroxine) after developing hypothyroidism.

Option A: Hypocalcemia is caused by damage to or removal of the parathyroid glands, which regulate calcium levels.
Option C: While there is a theoretical risk of radiation-induced cancer, multiple long-term studies have shown that the risk of malignancy following therapeutic doses of ¹³¹I for hyperthyroidism is negligible or very small.
Option D: Recurrence of hyperthyroidism occurs when the dose of radioactive iodine is insufficient to destroy enough thyroid tissue.

Clinical Relevance

Nursing practice connection: Knowing Complications of Radioactive Iodine Therapy helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
A key nursing role is patient education. Patients must understand that hypothyroidism is a highly probable outcome and be prepared for the necessity of lifelong levothyroxine replacement therapy.
Nurses are responsible for monitoring patients post-RAI for the signs and symptoms of developing hypothyroidism, such as fatigue, weight gain, cold intolerance, constipation, and depression.
What if? If the patient had undergone a total thyroidectomy instead of RAI therapy, the most immediate post-operative nursing priorities would be monitoring for respiratory distress (due to laryngeal nerve injury or hematoma) and hypocalcemia (tingling, muscle cramps), rather than the slower onset of hypothyroidism.

How to Approach the Question

First, identify the key components of the question: the specific treatment ('radio iodine therapy') and what is being asked ('most common complication').
Recall the mechanism of action for radioactive iodine: it is taken up by the thyroid and destroys hormone-producing cells.
Logically deduce the outcome of destroying a hormone-producing gland. The gland will no longer be able to produce its hormone, leading to a deficiency state (hypothyroidism).
Differentiate this primary outcome from complications of other treatments. For example, associate hypocalcemia with surgery (thyroidectomy) due to proximity to the parathyroid glands.
Evaluate the likelihood of the other options. Recurrence means the treatment failed, which is less common than the treatment succeeding and causing the expected hypothyroidism. Malignancy is a serious but rare risk.

Concept Tested & Keywords

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