The thyroid gland.

Disorders of the thyroid gland are frequently unrecognized and untreated by the attending physician and present the anesthesiologist with a diagnostic and therapeutic challenge. Very large goiters distort and compress the larynx and require an experienced anesthesiologist for safe intubation. If surgery is elective and can be postponed in patients suspected of being hypo- or hyperthyroid, there is sufficient time to permit the anesthesiologist and the attending physician to obtain appropriate tests of thyroid function and institute appropriate therapeutic measures to restore the metabolic rate to normal. When there is insufficient time to confirm a clinical diagnosis of thyroid disease, the anesthesiologist is faced with important therapeutic decisions. It is the author's opinion that therapeutic intervention is, in most instances, preferable to therapeutic nihilism. In the case of a patient suspected of hypothyroidism, it is usually safe to administer a physiologic replacement dose of thyroxine to support the patient intraoperatively or postoperatively. If hypothyroidism is associated with cardiovascular disease, other debilitating illness, or advanced age, thyroxine must be given with extreme caution in order to avoid dangerous tachyarrhythmias or too rapid acceleration of the metabolic rate. The hyperthyroid patient facing nonelective surgery represents a very serious challenge to the anesthesiologist, since marked accentuation of clinical hyperthyroidism (thyroid storm) is a major risk of such surgery. In such a situation, intravenous propranolol and intravenous iodine are the optimal drugs for a safe and uncomplicated clinical course during and following surgery. In both instances, the anesthesiologist must use skillful clinical judgment in making the appropriate diagnosis and selecting appropriate therapy. Careful and continuous supervision of the patient is necessary during and following surgery and appropriate treatment and support of the patient should be provided until it is safe to discontinue therapy, if necessary, to confirm the diagnosis of thyroid disease. Careful clinical judgment and judicious use of appropriate medication should provide the patient with a smooth and safe intraoperative course and a rapid and uncomplicated postoperative recovery.