Thyroid function Flashcards
What THREE clinical signs are most useful when considering thyroid function?
Weight
HR
Tremor
Compare & contrast HYPER & HYPO thyroidism in ELEVEN clinical signs
Hyper/Sign&Sx/Hypo down/Energy/down anxious/Mood/depressed up, nausea/GI/down, constipation loss/Wt/gain amenorrhoea/Menstrual/menorrhagia down/MSK/down down or agitated/Cognition/down up/Temperature/down RAF or palpitations/Heart Rate/reduced or CCF tremor or hyperreflexive/Neuro/Hyporeflexive
Name FOUR types of medication that interfere with thyroid tests:
Thyroxine (artificial TH)
PTU (propylthiouracil) (stops thyroxine formation by preventing Iodine binding to TG)
Amiodarone (inc or dec TH)
Lithium (inc or dec TH)
What is the most useful test of thyroid function?
TSH
Draw the ‘Gome’ thryoid tictactoe matrix.
Use this matrix to identify and name 9 types of thyroid status.
- Primary HYPO thyroidism
- Subclinical HYPO thyroidism - almost about to fail.
- Secondary HYPER thyroidism
- Repeat the test - usually normal function
- Euthyroid
- Repeat the test - usually normal function
- Secondary HYPO thyroidism
- Subclinical HYPER thyroidism
- Primary HYPER thryoidism
What group of patients should not be given TFTs? Why not?
Pts in ICU - because their illness causes their TFTs to be deranged and meaningless.
When would there be a high fT3?
Why?
In a T3 thyrotoxicosis.
Most T3 is bound, and free T3 is usually kept constant (based on the amount of TBG).
If a patient has secondary hypothyroidism, what is your major concern?
Given secondary hypothyroidism means an inactive pituitary gland, the major concern is the lack of glucocorticoids - from the lack of ACTH. So, primary Rx is to give steroids. Thyroxine supplementation is important but not as critical.
Referring to Gome’s thyroid tictactoe, TFTs that show normal to low TH & TSH suggest what diagnosis?
SES - sick euthyroid syndrome.
When is iodine supplementation NOT recommended?
In the thyrotoxic - those with high TSH.
To avoid cretinism, who and what should be tested? Why? What medication should be used?
Maternal TSH should be tested.
Iodine is to difficult to test and too difficult to monitor.
Give thyroxine to ensure that the baby is sufficiently developed.
Name the FOUR clinical reasons to remove a thyroid gland?
Hyperthyroidism
Cancer
Mass effects (no swallowing, breathing etc)
Cosmesis (appearance)
Name the FOUR types of thyroid cancer:
Papillary
Follicular
Anaplastic
Medullary
Which TWO are collectively known as DTC: differentiated thyroid cancer.
What is the treatment for DTC?
Papillary and Follicular
Total thyroidectomy then Rx with radioactive iodine (I131) followed by thyroxine replacement starting low and titrating to effect.
Which is the WORST type of thyroid cancer to get? Why? What is the Rx?
Anaplastic.
The mortality is typically <10% survival in 5/12 as people typically asphyxiate.
Morphine and a holiday.