If the thyroid gland is enlarged, then careful consideration is needed for airway management. The main complications are obstruction and aspiration.
Intraoperatively, thyroid storm may be difficult to distinguish from malignant hyperthermia (MH). Thyroid storm manifests as sinus tachycardia, atrial fibrillation, hypercapnia, hypertension, hyperthermia and diaphoresis (sweating). These complications can be treated with medication.
In patients with exophthalmus, special precautions are taken to avoid corneal injury and drying. The eyes are usually lubricated and taped.
Hyperthyroid patients may have an exaggerated sympathetic response to endogenous catecholamines released during intubation or surgical stress. Treatment with adrenergic blockers is sometimes appropriate.
In hypothyroid patients, the central nervous system and heart are highly sensitive to the depressant effects of many of the anaesthetic drugs. These are rare and may present as:
Hypothyroid patients are susceptible to hyponatremia due to the impaired free water clearance, therefore isotonic i.v. fluids are indicated. In extreme cases, hypertonic saline and thyroxine administration may be necessary.