Flashcards
Hypothyroidism & Hyperthroidism
Cards in this deck (31)
- 1Hypothyroidism: incidenceOvert: women 2%, men 0.2%
Subclinical: women 6-8%, men 3%
2.5% of pregnant women develop hypothyroidism - 2Hypothyroidism: causes of primaryAutoimmune: Hashimoto's and atrophic thyroiditis
Iatrogenic: surgery, radio-iodine
Drugs: amiodarone, contrast, lithium
Congenital
Infiltration of the thyroid - eg, amyloidosis, sarcoidosis - 3Hypothyroidism: causes of secondaryIsolated TSH deficiency.
Hypopituitarism: neoplasm, infection, infiltrative, radiotherapy
Hypothalamic disorders: neoplasm, trauma - 4Presentation of hypothyroidismTiredness, lethargy, intolerance to cold
Dry skin and hair loss
Slowing of intellectual activity
Constipation, reduced libido
Decreased appetite with weight gain
Menorrhagia and later oligo/amenorrhoea - 5Signs of hypothyroidismDry coarse skin, hair loss and cold peripheries.
Puffy face, hands and feet (myxoedema).
Bradycardia.
Delayed tendon reflex relaxation.
Carpal tunnel syndrome.
Serous cavity effusions - 6What antibodies are found in 90-95% of patients with autoimmune hypothyroidism?Anti-thyroid peroxidase (anti-TPO)
(anti-thyroglobulin) - 7Investigation for suspected hypothyroidismSerum TSH and T4 (+T3)
- 8Management of clinical hypothyroidismLevothyroxine
Initial dose 50-100 micrograms once daily, adjusted in steps of 25-50 micrograms every 3-4 weeks according to response
Usual maintenance dose = 100-200 - 9For which patients is an initial dose of 25 micrograms and increases of 25 recommended?Patients with cardiac disease.
Patients with severe hypothyroidism.
Patients aged over 50 years - 10Hypothyroidism and pregnancyWomen of childbearing age should be encouraged to wait until euthyroid to conceive
Maintain a euthyroid state throughout pregnancy (esp. 1st trimester) - 11Clinical features of myxoedema comaA reduced level of consciousness.
Seizures
Hypothermia
Features of hypothyroidism. - 12Precipitating factors for myxoedema comaInfections
Discontinuation of thyroid supplements
Sedative drugs
Anything that impairs the respiratory system e.g. pneumonia, HF, MI - 13Hyperthyroidism: what is the most common cause of thyrotoxicosis?Graves'
- 14Thyrotoxicosis due to toxic nodular goitre is more common in which group?Over 60s
- 15Causes of secondary hyperthyroidismTSH-secreting pituitary adenoma.
Thyroid hormone-resistance syndrome.
hCG-secreting tumour.
Gestational thyrotoxicosis - 16Hyperthyroidism: risk factorsFH
Smoking
High iodine intake.
Trauma to the thyroid gland
Toxic multinodular goitre (esp. associated with increased iodine intake)
Childbirth.
Highly active antiretroviral therapy (HAART) - 17Hyperthyroidism: symptomsWeight loss despite an increased appetite
Irritability, weakness and fatigue
Diarrhoea ± steatorrhoea
Sweating, tremor
Mental illness
Heat intolerance
Loss of libido, a/oligomenorrhoea - 18Hyperthyroidism: signsPalmar erythema, sweaty and warm palms
Fine tremor
Tachycardia
Hair thinning or diffuse alopecia
Urticaria, pruritus
Brisk reflexes
Goitre, lid lag
Proximal myopathy, gynaecomastia - 19Precipitating factors for thyroid stormWithdrawal of an anti-thyroid drug
Radio-iodine therapy
Infection
Surgery - 20What is the mechanism of Graves'?Thyroid-stimulating immunoglobulins bind to TSH receptors which stimulates the secretion of T4 and T3
- 21Clinical features of Graves'Eye changes: exopthalmos, opthalmoplegia
Diffuse moderate enlargement of the thyroid gland which feels firm on palpation
Sometimes pretibial myxoedema - 22Differentials for hyperthyroidismPhaechromocytoma
Any cause of weight loss - 23Investigations for suspected hypothyroidismTFTs
Autoantibodies: Anti-TPO, antithyroglobulin, TSH-receptor
Thyroid US - 24Management of new-onset thyrotoxicosis in primary careAll patients with new-onset thyrotoxicosis should be referred for assessment in secondary care, to establish the cause and to agree on a management plan
- 25What can be given for rapid symptom control whilst waiting for thyroid function to normalise?Beta-blockers
- 26Management of hyperthyroidism: drug therapyCarbimazole
2 methods: a) block and replace, b) dose titration. Both equally effective, b) associated with lower rate of side effects
Full benefit may take 2-3 weeks
Most Graves' euthyroid by 4-8 weeks
TFTs every month, dose altered to T4 levels
Once euthyroid, reduce to lowest possible maintenance dose - 27Carbimazole: remission, side effects and cautionsRemission usually achieved at 18-24 months, after which attempts may be made to stop drug therapy
SE: nausea and bitter taste
Warn patients to come for FBC if they develop a sore throat - drugs can cause bone marrow suppression - 28Management of hyperthyroidism: radio-iodine1st-line treatment in teenagers
Given as a drink, taken up by thyroid and destroys gland. 3-4 months to take effect
Anti-thyroid drugs should be stopped 5-7 days before treatment
Contraindicated to pregnancy
May worsen Graves' eye disease
Hypothyroidism is a complication - 29Management of hyperthyroidism: surgeryShould be returned to the euthyroid state with anti-thyroid drugs before
98% cure rate, may cause hypo -> need long-term follow up
Indications: suboptimal response to anti-thyroid medication or radio-iodine
Complications (rare): haemorrhage, hypoparathyroidism and vocal cord paralysis - 30Summary of management of hyperthyroidism in primary careEducate them on the nature of the illness and the management plan.
Start carbimazole.
Warn the patient of the importance of seeking urgent help if they develop a sore throat or a rash.
Consider starting a beta-blocker or calcium-channel blocker to control symptoms driven by the sympathetic nervous system - eg, atenolol or verapamil. - 31—
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- Community Based Medicine Flashcards on Hypothyroidism & Hyperthroidism, created by Liam Musselbrook on 16/02/2017.
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