A 55 year old male patient underwent cholcystectomy for Gall stone calculus. During surgery the patient’s pulse was irregulary irregular, 160/min, BP = 80/ 50 mm of Hg, temp.40o c On examination a swelling in the neck was found. Most likely diagnosis is

**Core Concept**
The patient's presentation of irregularly irregular pulse, tachycardia, hypotension, and fever, in the context of a recent surgical procedure, suggests a postoperative complication involving the thyroid gland. This scenario likely involves a thyroid storm, a life-threatening condition that arises from untreated or inadequately treated hyperthyroidism.

**Why the Correct Answer is Right**
The patient's symptoms and signs are consistent with a thyroid storm, which is often precipitated by stress, such as surgery. The irregularly irregular pulse is a classic sign of atrial fibrillation, a common cardiac complication in thyroid storm. The fever, tachycardia, and hypotension are also typical of this condition. The swelling in the neck is likely a thyroid gland that has become inflamed and enlarged due to the hyperthyroid state.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided.
* **Option B:** This option is not provided.
* **Option C:** This option is not provided.
* **Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
Thyroid storm can be precipitated by a variety of factors, including surgery, infection, and trauma. It is essential to diagnose and treat hyperthyroidism before any surgical procedure to prevent this life-threatening complication.

**Correct Answer: D. Thyroid storm.**

✓ Correct Answer: A. Thyroid storm