Clin Med - Thyroid (Carlozzi) Flashcards
Given a patient’s symptoms, identify as hypothyroid
- 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
Select the laboratory orders of choice to diagnose hypothyroidism
- TSH-always first test performed
- Additional tests: free T4, thyroid autoantibodies (anti-thyroid peroxidase and antithyroglobulin autoantibodies), thyroid ultrasound (if suspicious of nodules)
Define subclinical hypothyroidism
- Mildly elevated TSH and
- Could represent early thyroid failure
Identify the patients to refer to an endocrinologist
- 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
Identify the causes of hyperthyroidism
- 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)
Given a patient’s signs and symptoms, identify as hyperthyroidism
- 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
Given a TSH and T4, identify the patients as having hyperthyroidism
Hyperthyroidism: suppressed TSH (<0.3), elevated T4 and T3
Given a patient’s symptoms, diagnose thyroid storm
- tachy, arrhythmias, CHF, hypotension
- hyperpyrexia
- agitation, delirium, psychosis, stupor, coma
- n/v/d
- hepatic failure
Given a patient with subclinical hyperthyroidism, state diagnostic criteria
- Suppressed TSH and normal T4/T3
- Confirm that it is persistent problem by repeating labs in 3-6 months (some resolve spontaneously)
State the complications of untreated subclinical hyperthyroidism
- 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
state the diagnostic criteria of hyperthyroidism in pregnancy
- 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
Describe the 3 phases of postpartum thyroiditis
a. Thyrotoxicosis at 1-6 months postpartum
b. Hypothyroidism
c. Return to euthyroidism at 9-12 months postpartum
Identify the precautions that should be discussed with a patient who is prescribed radioactive iodine
- 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
Given a set of patients with thyroid disorders, select the patient who is a candidate for radioactive iodine
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
State the complications of RAI therapy
- 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
contraindications to RAI therapy
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
Outline therapy of thyroid storm
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
Outline pediatric treatment of Grave’s disease
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
Identify the treatment options for postpartum thyroiditis
- If symptomatic: use β-blockers (propranolol has lowest level in breast milk)
- Levothyroxine therapy beneficial at least during second stage
