Thyroid stuff Flashcards
low T4, high TSH = ?
what is the one exception to this?
hypothyroidism
unless pituitary problem where it’s not secreting TSH
high T4, low TSH = ?
hyperthyroidism
TSH is suppressed by high T4
Name 5 etiologies of hypothyroid.
- Hashimoto’s thyroiditis – autoimmune (family history)
- Iatrogenic - surgery, radiation
- Drugs - amiodarone, lithium, iodine def.
- Subacute/Postpartum thyroiditis
- Congenital
What is the SLUGGISH acronym for the symptoms of hypothyroidism?
- Sleepiness/fatigue
- Loss of memory
- Unusually dry skin
- Goiter
- Gradual personality change/depression
- Increased weight/bloating/puffiness
- Sensitivity to cold
- Hair loss
What is the treatment for hypothyroid?
• Levothyroxine - synthetic T4 - convert to T3
What is the life-threatening hypothyroid crisis?
myxedema - mental status changes, hypothermia, risk of hypoventilation
What is the life-threatening hyperthyroid crisis?
thyroid storm - tachycardia, high output HF, wide pulse pressure, elevated SBP, fever, mental status changes
What are three causes of thyrotoxicosis (hyperthyroidism)?
- Graves disease
- Toxic multinodular goiter
- Drugs: amiodarone, interferon, iodinated contrast
What is exophthalmos a sign of?
Graves disease
What are eye physical findings of hyperthyroidism?
lid lag, retraction, stare
Treatment of acute hyperthyroid?
- BB (propranolol)
- meds to block T4 synthesis:
~propylthiouracil
~methimazole
Beyond the treatments for acute hyperthyroid, what are two treatments for Graves disease?
- radioactive iodine
2. thyroid surgery
What are contraindications to treating patient with radioactive iodine?
Absolute contraindication: PREGNANCY or RISK OF PREGNANCY or LACTATING Relative contraindications: 1. presence of Graves ophthalmopathy 2. smoking
Usually goiter in Hashimoto, Graves, and multinodular goiter is painless.
T/F
True
May be painful in suppurative thyroiditis, hemorrhage, subacute thyroiditis
Patient has goiter. What is your workup?
- thyroid function tests
- radioactive iodine scan
- ultrasound maybe
When do you worry about cancer with a thyroid nodule?
nodules > 1 cm
Which thyroid nodules need to be biopsied and which don’t?
~”cold” nodules (nodules not producing thyroid hormone) need to be biopsied
~”hot” nodules (nodules producing thyroid hormone) are rarely malignant; no biopsy
What is the treatment for thyroid cancer?
– Thyroidectomy
– I-131 ablation of residual and recurrent disease
– Levothyroxine to keep TSH mildly suppressed
What is the followup for thyroid cancer?
• Follow-up: For life! – Recurrences decades later – Yearly thyroglobulin levels – Periodic I-131 whole body scans – CT/MRI Ultrasound PET
Which hyperthyroid medication crosses the placental barrier and which doesn’t?
methimazole crosses placenta
propylthiauracil does not cross
What monitoring is done while patients are on methimazole/propylthiauracil?
CBC for leukopenia, agranulocytosis
What is the most common type of hypothyroid?
Hashimoto’s disease
What is euthyroid sick syndrome?
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…)
Pregnancy with Hypothyroidism - bad or no big deal?
• Hypothyroidism in pregnancy is BAD
– Associated with miscarriage, preeclampsia, low birth
weight, impaired intellectual development of fetus
