Thyroid stuff

Question 1

low T4, high TSH = ?

what is the one exception to this?

Answer 1

hypothyroidism

unless pituitary problem where it’s not secreting TSH

Question 2

high T4, low TSH = ?

Answer 2

hyperthyroidism

TSH is suppressed by high T4

Question 3

Name 5 etiologies of hypothyroid.

Answer 3

• Hashimoto’s thyroiditis – autoimmune (family history)
• Iatrogenic - surgery, radiation
• Drugs - amiodarone, lithium, iodine def.
• Subacute/Postpartum thyroiditis
• Congenital

Question 4

What is the SLUGGISH acronym for the symptoms of hypothyroidism?

Answer 4

• Sleepiness/fatigue
• Loss of memory
• Unusually dry skin
• Goiter
• Gradual personality change/depression
• Increased weight/bloating/puffiness
• Sensitivity to cold
• Hair loss

Question 5

What is the treatment for hypothyroid?

Answer 5

• Levothyroxine - synthetic T4 - convert to T3

Question 6

What is the life-threatening hypothyroid crisis?

Answer 6

myxedema - mental status changes, hypothermia, risk of hypoventilation

Question 7

What is the life-threatening hyperthyroid crisis?

Answer 7

thyroid storm - tachycardia, high output HF, wide pulse pressure, elevated SBP, fever, mental status changes

Question 8

What are three causes of thyrotoxicosis (hyperthyroidism)?

Answer 8

1. Graves disease
2. Toxic multinodular goiter
3. Drugs: amiodarone, interferon, iodinated contrast

Question 9

What is exophthalmos a sign of?

Answer 9

Graves disease

Question 10

What are eye physical findings of hyperthyroidism?

Answer 10

lid lag, retraction, stare

Question 11

Treatment of acute hyperthyroid?

Answer 11

1. BB (propranolol)
2. meds to block T4 synthesis:
   ~propylthiouracil
   ~methimazole

Question 12

Beyond the treatments for acute hyperthyroid, what are two treatments for Graves disease?

Answer 12

1. radioactive iodine

2. thyroid surgery

Question 13

What are contraindications to treating patient with radioactive iodine?

Answer 13

Absolute contraindication:
PREGNANCY or RISK OF PREGNANCY or LACTATING
Relative contraindications:
1. presence of Graves ophthalmopathy
2. smoking

Question 14

Usually goiter in Hashimoto, Graves, and multinodular goiter is painless.
T/F

Answer 14

True

May be painful in suppurative thyroiditis, hemorrhage, subacute thyroiditis

Question 15

Patient has goiter. What is your workup?

Answer 15

1. thyroid function tests
2. radioactive iodine scan
3. ultrasound maybe

Question 16

When do you worry about cancer with a thyroid nodule?

Answer 16

nodules > 1 cm

Question 17

Which thyroid nodules need to be biopsied and which don’t?

Answer 17

~”cold” nodules (nodules not producing thyroid hormone) need to be biopsied
~”hot” nodules (nodules producing thyroid hormone) are rarely malignant; no biopsy

Question 18

What is the treatment for thyroid cancer?

Answer 18

– Thyroidectomy
– I-131 ablation of residual and recurrent disease
– Levothyroxine to keep TSH mildly suppressed

Question 19

What is the followup for thyroid cancer?

Answer 19

• Follow-up: For life!
– Recurrences decades later
– Yearly thyroglobulin levels
– Periodic I-131 whole body scans
– CT/MRI Ultrasound PET

Question 20

Which hyperthyroid medication crosses the placental barrier and which doesn’t?

Answer 20

methimazole crosses placenta

propylthiauracil does not cross

Question 21

What monitoring is done while patients are on methimazole/propylthiauracil?

Answer 21

CBC for leukopenia, agranulocytosis

Question 22

What is the most common type of hypothyroid?

Answer 22

Hashimoto’s disease

Question 23

What is euthyroid sick syndrome?

Answer 23

Patients with abnormal thyroid function tests (eg, low serum T4 and low levels of FT4) without thyroid disease; conditions that can result in this syndrome include severe illness, caloric deprivation, or major surgery. Patients who have undergone major surgery may have accelerated peripheral metabolism of serum T4 to reverse T3 (rT3).

• All changes resolve when recovered from
illness
• Acute severe illness
• Impaired conversion of T4 → T3
• Most common causes (Cancer, malnutrition,
infection, Pulm dz, renal dz, liver dz…)

Question 24

Pregnancy with Hypothyroidism - bad or no big deal?

Answer 24

• Hypothyroidism in pregnancy is BAD
– Associated with miscarriage, preeclampsia, low birth
weight, impaired intellectual development of fetus