What are the preoperative considerations in a patient with thyroid disease?

What are the preoperative considerations in a patient with thyroid disease?

The first, and most important, consideration is whether the patient is clinically euthyroid. Patients who are euthy-roid or minimally hypothyroid are generally at no increased perioperative risk. However, patients who are clinically hyperthyroid may have dysrhythmias, hyper-tension, ischemia, high-output cardiac failure, and ultimately may develop thyroid storm. Conversely, patients who are clinically hypothyroid may have bradycardia, hypotension, low-output cardiac failure, and resistance to catecholamines.

Patients who are hyperthyroid must be treated preoper-atively. For elective cases, this should include PTU or methimazole until the patient is euthyroid, which may take 6–8 weeks of therapy. The addition of β-blocking agents may also be necessary. For urgent or emergent cases, the patient should be treated with β-blocking agents.

Profoundly hypothyroid patients should receive intra-venous T₄ before surgery. Patients should be observed care-fully for dysrhythmias or angina.

Any patient with a goiter must be evaluated for airway compromise. Large goiters can cause distortion of the air-way, making intubation difficult or impossible. Goiters also make emergency surgical access of the airway difficult if not impossible and therefore should not be considered a viable emergency back-up plan. Retrosternal goiters can cause collapse of the airway after induction of general anesthesia. Symptoms such as dysphagia, wheezing, stri-dor, and positional dyspnea are worrisome and necessitate further evaluation (see below). Physical examination should include the standard evaluation of the airway, as well as position of the trachea. Any plan for an awake fiberoptic intubation should be discussed with the patient preoperatively.

Patients who are euthyroid or hyperthyroid can safely receive preoperative anxiolysis. However, premedication in patients who are hypothyroid should be avoided because they may have an exaggerated and life-threatening response to anxiolysis.