“What sedation is used for thyroid surgery?”

You would require a general anesthetic and not sedation for thyroid surgery.

I suspect that your question regards the overall type of anesthesia to be administered during a proposed thyroid surgery. I have only administered general anesthesia during thyroid surgery. That would include sedation on the way to the operating room, typically Versed (midazolam) which is a benzodiazepine which ion the same family as Valium, Ativan, and Xanax, all drugs which give a patient a sense of tranquility, what we call "anxiolytics" in other words, diminish anxiety. Once in the operating room, the vital sign monitors are reconnected: pulse oximeter, blood pressure and the electrocardiogram. The patient is administered oxygen via an oxygen mask and the general anesthetic is initiated with intravenous medications. Once the patient is completely asleep, an endotracheal tube (breathing tube) is placed into the trachea (wind pipe). The patient is prepped with the surgical solution, sterile drapes are placed and the surgeon commences with the surgery.
I personally have never participated in a thyroid surgery under local anesthesia with sedation. It would be inappropriate for me to have any opinion regarding that form of anesthesia care. I hope this helps.

Usually general anesthesia.

General anesthesia, not sedation.

General