Clin Med - Thyroid (Carlozzi)

Question 1

Given a patient’s symptoms, identify as hypothyroid

Answer 1

• Fatigue
• Weight gain from fluid retention
• Myalgias
• Constipation
• Cold intolerance
• Dry skin
• Coarseness/loss of hair
• Hoarseness
• Diminished reflexes
• Goiter
• Memory/mental impairment
• Depression
• Irregular menses/infertility
• Bradycardia/hypothermia
• Myxedema fluid infiltration of tissues

Question 2

Select the laboratory orders of choice to diagnose hypothyroidism

Answer 2

• TSH-always first test performed
• Additional tests: free T4, thyroid autoantibodies (anti-thyroid peroxidase and antithyroglobulin autoantibodies), thyroid ultrasound (if suspicious of nodules)

Question 3

Define subclinical hypothyroidism

Answer 3

• Mildly elevated TSH and

- Could represent early thyroid failure

Question 4

Identify the patients to refer to an endocrinologist

Answer 4

• Pregnant patients
• Patients unresponsive to therapy
• Cardiac patients
• Presence of large goiter or of nodules in thyroid gland
• Other endocrine abnormalities present
• Patients age 18 or less
• Secondary hypothyroidism

Question 5

Identify the causes of hyperthyroidism

Answer 5

• MC cause is Grave’s Disease: toxic diffuse goiter
• Others: toxic multinodular goiter (Plummer’s disease), toxic solitary nodule, subacute thyroiditis, silent thyroiditis, post-partum thyroiditis, iodine induced thyroiditis, excessive pituitary TSH, iatrogenic hyperthyroidism (too much levothyroxine)

Question 6

Given a patient’s signs and symptoms, identify as hyperthyroidism

Answer 6

• Fatigue
• Palpitations/tachycardia
• Muscle weakness
• Heat intolerance/increased sweating
• Weight loss
• Alterations in appetite
• Diarrhea
• Increased bone turnover with elevated Alkaline Phosphatase
• Dyspnea
• Menstrual irregularities
• Impaired infertility
• Mental disturbances
• Sleep disturbances
• Changes in vision, photophobia, eye irritation, diplopia, exophthalmos
• Thyroid enlargement
• Pretibial myxedema

Question 7

Given a TSH and T4, identify the patients as having hyperthyroidism

Answer 7

Hyperthyroidism: suppressed TSH (<0.3), elevated T4 and T3

Question 8

Given a patient’s symptoms, diagnose thyroid storm

Answer 8

• tachy, arrhythmias, CHF, hypotension
• hyperpyrexia
• agitation, delirium, psychosis, stupor, coma
• n/v/d
• hepatic failure

Question 9

Given a patient with subclinical hyperthyroidism, state diagnostic criteria

Answer 9

• Suppressed TSH and normal T4/T3

- Confirm that it is persistent problem by repeating labs in 3-6 months (some resolve spontaneously)

Question 10

State the complications of untreated subclinical hyperthyroidism

Answer 10

• Deleterious effects on CV system (2.8-fold risk of a-fib in those >60 with this)
• Skeletal system (postmenopausal women may have increased fracture rates)
• Altered cognition possible and/or other symptoms of thyrotoxicosis

Question 11

state the diagnostic criteria of hyperthyroidism in pregnancy

Answer 11

• TSH and either total T4 or T3 OR FT4 and FT3 estimations with trimester-specific normal reference ranges
• Reference ranges for T4/T3 adjusted at 1.5 times the nonpregnant range

Question 12

Describe the 3 phases of postpartum thyroiditis

Answer 12

a. Thyrotoxicosis at 1-6 months postpartum
b. Hypothyroidism
c. Return to euthyroidism at 9-12 months postpartum

Question 13

Identify the precautions that should be discussed with a patient who is prescribed radioactive iodine

Answer 13

• No exchange of saliva for 5 days, wash dishes in dishwasher if possible
• Avoid close contact with children <8 y/o and pregnant woman for 5 days (it is okay to be in the same room)
• No breast-feeding
• Flush the toilet twice after urinating, wash hands thoroughly
• Use acetaminophen/aspirin if sore throat/neck pain develops

Question 14

Given a set of patients with thyroid disorders, select the patient who is a candidate for radioactive iodine

Answer 14

a. Females planning pregnancy in the future
i. Higher risk involved with taking ATD during pregnancy
ii. Females should wait 4-6 months after procedure before attempting conception
iii. Males should wait 3-4 months to allow for turnover of sperm production
b. High surgical risk patients
c. Patients with previously operated/irradiated necks
d. No access to an experienced thyroid surgeon
e. Contraindications to ATDs exist

Question 15

State the complications of RAI therapy

Answer 15

• Lifelong levothyroxine therapy
• Thyroid storm can occur after administration but is rare
• Slight possibility of 2nd procedure due to failure of radioactive iodine
• Risk of worsening ophthalmopathy

Question 16

contraindications to RAI therapy

Answer 16

a. Pregnancy
b. Lactation (wait until 6 months after)
c. Coexisting thyroid cancer (or suspicion of)
d. Unable to comply with radioactive iodine safety guidelines
e. Females planning pregnancy within 4-6 months

Question 17

Outline therapy of thyroid storm

Answer 17

a. Β-blocker therapy: propranolol 60-80mg Q4 hours
b. ATD: PTU 500-1000 mg load, then 250mg Q4 hours, methimazole 60-80mg/day
c. Inorganic iodine: started 1 hour after ATD, given Q6 hours
d. Corticosteroid therapy: hydrocortisone 300mg IV load, then 100mg Q8 hours
e. Aggressive cooling with acetaminophen and cooling blankets
f. Volume resuscitation
g. Respiratory support and monitoring in ICU

Question 18

Outline pediatric treatment of Grave’s disease

Answer 18

a. Methimazole, radioactive iodine, thyroidectomy
b. Avoid radioactive iodine in children under 5
c. Children 5-10 y/o can have radioactive iodine if calculated dose is <10mCi
d. Β-blockers recommended if HR>100bpm

Question 19

Identify the treatment options for postpartum thyroiditis

Answer 19

• If symptomatic: use β-blockers (propranolol has lowest level in breast milk)
• Levothyroxine therapy beneficial at least during second stage