Patients with undiagnosed or untreated hyperthyroidism who undergo anesthesia and surgery are at high risk for thyroid storm, a provoked crisis of multiorgan failure, he said.
If the surgery cannot be delayed until elevated levels of thyroxine are achieved, the team can initiate oral or intravenous beta-blockade, or if the patient is in critical condition, infusion with the beta-1 receptor blocker esmolol (Brevibloc) is preferred, he said.
Patients should also be started on methimazole 30-40 mg/day, and the patient should be given iodine if she has not already received iodinated radiologic contrast. Stress dose glucocorticoids and adequate volume resuscitation may also provide support in this situation.
In contrast, "hypothyroidism is usually not a big deal," Dr. Baldwin said.
Such patients usually tolerate major surgery without significant complications, he said, but patients with hypothyroidism may be more sensitive to sedatives, slower to wean from ventilation, and handle free-water excretion less well than euthyroid patients.
Patients who take levothyroxine (Synthroid and generics) should always have their free T4 and thyroid-stimulating hormone (thyrotropin) levels checked during preoperative evaluation, he said.
Dr. Baldwin reported having no relevant financial conflicts of interest.