Thyrotoxicosis Flashcards
What are symptoms of thyrotoxicosis?
Diarrhoea Weight loss Increased appetite Overactive Sweats Heat intolerance Palpitations Tremor Irritability Labile emotiona Oligomenorrhoea Infertility
What investigations in thyrotoxicosis?
TFTs:
TSH low
T3 and T4 up
FBC: mild normocytic anaemia, mild neutropenia in Graves’
Raised ESR
Raised Ca
Raised LFTs
Check thyroid autoantibodies
test visual fields,a city and eye movements if eye disease
What are signs of thyrotoxicosis?
Fast/irregular pulse Warm moist skin Fine tremor PAlmar erythema Thin haie Lid lag Lid retraction (exposure of sclera above iris May be goitre
What are signs of Graves’ disease?
Eye disease - exophthalmos, ophthalmoplegia
Pretibial myxoedema: oedematous swellings above the lateral malleoli
Thyroid acropachy: extreme manifestation with clubbing, painful finger and toe swelling and periosteal reaction (formation of new bone) in limb bones
What is Graves’ disease
Circulating IgG antibodies bind to and activate GPCR thyrotropin receptors which cause smooth thyroid enlargement and increased hormone production , especially T3
Triggers: Stress, infection, childbirth
Patients are often hyperthyroid
Associated with other autoimmune diseases: vitiligo, T1DM, Addison’s
What is toxic multi nodular goitre?
Seen in elderly and in iodine deficient areas
Nodules that secrete thyroid thormone.
What is toxic adenoma?
Solitary nodule producing T3 and T4
What an be the cause of exogenous hyperthyroidism
Iodine excess e.g. food contamination, contrast medium.
Levothyroxine excess causing raised T4, low T3 and low thyroglobulin.
What drugs can cause hyperthyroidism?
Amiodarone
Lithium (hypothyroidism is more common)
What is the pharmacological management for thyrotoxicosis?
Beta-blockers (propanolol) for rapid control of symptoms
Anti-thyroid medication:
A titration - carbimazole for 4 weeks, reducing according to TFTs every 1-2 months
B Block-replace
Carbimazole and levothyroxing simultaneously (less risk of iatrogenic hypothyroidism)
In Graves’ maintain on either for 12-18 months then withdraw
What are side effects of carbimazole?
Agranulocytosis (neutropenia can lead to sepsis)
Warn to stop and get an urgent FBC if signs of infection e.g. fever, sore throat, ulcers
What other management of thyrotoxicosis?
Radioiodine: most become hypothyroid post-treatment
CI: pregnancy, lactation
Thyroidectomy (usually total): Carries risk of damage to recurrent laryngeal nerve (hoarse voice) and hypoparathyroidism.
Patients will become hypothyroid so thyroid replacement is needed
What are complications of hyperthyroidism?
Angina Heartfailure (thyrotoxic cardiomyopathy) Angina AF Ostoporosois Thyroid storm (thyrotoxic crisis)
What are signs an symptoms of thyroid storm?
Severe hypothyroidism Fever Agitation Confusion Coma Tachycardia AF Diarrhoea and vomiting Goitre Thyroid bruit Acute abdomen Heart failure
What precipitates thyroid storm?
Recent thyroid surgery or radioiodine,
infection
MI
Trauma
How to trat thyroid storm
Contact endocrinology
Bloods for T3, T4. TSH
IV access - fluids
Beta blocker - propranolol if no contraindication (e.g. asthma/poor cardiac output) - diltiazem if CI
High dose digoxin to slow the heart
Carbimazole to block thyroid
Hydrocortisone IV or dexamethasone PO to prevent peripheral conversion of T4 to T3
Treat infection
What re symptoms of thyroid eye disease?
Eye discomfort, grittiness, increased tear production, photophobia, diplopia, reduced acuity, relative afferent pupillary defect (RAPD) - patients pupils contract less when bright light is swung from unaffected to affected light so appearing to dilate –> may mean optic nerve compression
What are signs of thyroid eye disease?
Exophthalmos - appearance of protruding eye
Proptosis - eyes protrude beyond the orbit (look from above in the same plane as the forehead)
Conjunctival oedema
Corneal ulceration
Papilloedema
Loss of colour vision
Ophthalmoplegia especially of upward gaze due to muscle swelling and fibrosis
How to manage thyroid eye disease?
Treat hyper/hypothyroidism
Stop smoking
Symptomatic treatment - artificial tears, sunglasses’ cord dust
If severe high dose steroids
Surgical decompression for severe sight threatening disease
