Final answer:
Tingling around the mouth is the sign from the options provided that likely indicates the presence of hypocalcemia following a thyroidectomy. This symptom is related to the neuromuscular irritability resulting from a calcium deficit in the blood.
Step-by-step explanation:
The sign that likely indicates the presence of hypocalcemia in a client following a thyroidectomy is A. Tingling around the mouth. This symptom can be associated with the neuromuscular irritability that accompanies low calcium levels in the blood. After a thyroidectomy, there is a risk of accidentally removing or damaging the parathyroid glands, which leads to hypoparathyroidism and subsequent hypocalcemia. A sign indicating hypocalcemia is a positive Chvostek's sign, not a negative one. Flaccid paralysis and bradycardia are not directly indicative of hypocalcemia.
Hypocalcemia can impact many body systems, including the nervous and muscular systems, leading to symptoms such as muscle twitching, cramping, and convulsions. Severe deficits in calcium can even lead to muscle paralysis and fatal outcomes if not addressed promptly. Treatment for hypocalcemia varies based on the underlying cause but is generally effective when administered correctly.