Total thyroidectomy done for a female . Following the surgery she developed stridor and dyspnea. The possible cause is:
**Core Concept**
The question tests the understanding of a rare but life-threatening complication following total thyroidectomy, which is recurrent laryngeal nerve (RLN) injury. The RLN is closely associated with the thyroid gland and can be damaged during surgery, leading to vocal cord paralysis.
**Why the Correct Answer is Right**
The recurrent laryngeal nerve is responsible for innervating the intrinsic muscles of the larynx, including the posterior cricoarytenoid muscle, which is the only muscle responsible for opening the glottis. Damage to the RLN can lead to vocal cord paralysis, causing inspiratory stridor and dyspnea. The stridor is due to the incomplete closure of the glottis during inspiration, resulting in a high-pitched sound. The dyspnea is due to the reduced airflow through the glottis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the scenario, as a hemithyroidectomy (surgical removal of half the thyroid gland) is less likely to cause RLN injury compared to a total thyroidectomy.
* **Option B:** Although a hematoma can be a complication of thyroid surgery, it is not the most likely cause of stridor and dyspnea. A hematoma would more likely cause airway obstruction due to compression of the trachea.
* **Option D:** This option is not a direct consequence of thyroid surgery. Malignant pachydermoperiostosis is a rare genetic disorder characterized by thickening of the skin and periosteum of bones, but it is not related to thyroid surgery complications.
**Clinical Pearl / High-Yield Fact**
The recurrent laryngeal nerve is at risk during thyroid surgery due to its close proximity to the thyroid gland. Surgeons must take great care to identify and preserve the RLN to avoid postoperative complications.
**Correct Answer:** C. Recurrent laryngeal nerve injury.