Hyperthyroidism1 Flashcards
In which circumstances, a surgical approach to hyperthyroid disease would be reasonable?
When medical therapies have failed or are contraindicated, or when an informed patient chooses surgery based on its relative advantages and disadvantages compared with medical approaches.
Which immunoglobulin is elevated on hyperthyroidism?
Thyroid-stimulating immunoglobulin (TSI)
What are the treatment options for hyperthyroid patients?
Thionamide inhibitionﾠ(propylthiouracil or methimazole) andﾠradiation
What is the drug of choice for hyperthyroid pregnant patients?
Propylthiouracil (PTU)
What is Grave’s disease and what is the cause?
Graves disease is an autoimmune, toxic, diffuse goiter. It has a strong hereditary component. It is the cause of 50% to 80% of hyperthyroidism cases. Graves disease is caused by antibodies binding to and stimulating the TSH receptor, resulting in follicular hypertrophy and hyperplasia as well as excessive thyroid hormone synthesis and secretion.
What is the most serious side effect of the PTU?
Agranulocytosis
Is radioactive ablation effective treating hyperthyroidism?
Yes. It is highly effective, with 80% to 90% of patients achieving control of hyperthyroidism with a single dose in a dose-dependent fashion.
What is the definitive cure for patients with Grave’s disease?
Total thyroidectomy with a recurrence rate of less than 1%.
What is the incidence of occult carcinoma in patients with Graves disease and what is the most common type of carcinoma?
Occult carcinoma is discovered incidentally in about 2% of Graves specimens, and most are papillary carcinoma.
What percentage of Graves patients have clinically evident ophthalmopathy and which treatment has been found to be more effective improving the eye signs?
Manifestations of ophthalmopathy are clinically evident in 30% to 50% of Graves patients. Surgery might be slightly more effective, resulting in improvement in eye signs in as much as 85% of the population, but evidence is not conclusive.
What are the disadvantages of surgery in Graves patients?
Rates of nerve injury, parathyroid compromise, and bleeding appear to be slightly higher, possibly related to the enlarged thyroid, its firm consistency, venous engorgement, distortion of normal anatomy. The hypervascularity of these goiters makes control of intraoperative bleeding important, and postoperative bleeding rates are somewhat elevated.
What preoperative labs are needed for a hyperthyroid patient?
Calcium level and pregnancy test
What is the typical dose for PTU preoperatively in a hyperthyroid patient?
PTU at 50 to 100 mg by mouth three times a day
Why propanolol has been shown to be helpful preoperatively in hyperthyroid patients?
Propranolol has the added beneficial effect of inhibiting peripheral conversion of T4 to T3. Optimal propranolol doses vary by patient, from 40 to 320 mg/day, and half-life is just over 3 hours, mandating dosing three or four times daily.
What diagnostic test should be performed preoperatively on patients that have history of hoarseness and are about to undergo a thyroidectomy?
Direct laryngoscopy should be performed prior to anesthesia induction for patients with hoarseness to document preexisting vocal cord dysfunction.
