endocrine and metabolic Flashcards
Define Addison’s disease
primary adrenal insufficiency caused by adrenal cortex destruction
- low cortisol + elevated ACTH in response
- low aldosterone
- low adrenal androgens (DHEAP - dehydroepiandrosterone)
Causes of Addison’s disease
- TB
- autoimmune addison’s
Presenting symptoms of Addison’s
- fatigue
- hyperpigmentation (high ACTH+ high MSH => high )
- GI (weight loss, loss of appetite, vomiting + nausea, abdominal pain)
- dizziness
- muscle weakness + cramps (electrolyte imbalance)
- fever, headache
Examination findings for Addison’s disease
- postural hypotension (bp 20mmHg lower standing)
- other autoimmune (vitiligo, pernicious anaemia, coeliac disease)
- hyperpigmentation
- loss of body hair on women (less androgens)
- skin changes - darkening of elbows, under palms, gums
Investigations + findings for Addison’s disease
- 9am serum cortisol (<100nmmol/L = likely adrenal insufficiency
*cortisol= diurnal - Bloods:
- U&Es (low Na+, high K+)
- FBC (anaemia)
- Hypercalcemia
- low glucose
- TFTs (exclude hyperthyroidism)
- short Synacthen test (should in normals increase cortisol) - cortisol <500mmol/L in 30 mins = likely adrenal insufficiency
- plasma renin/ aldosterone levels
- serum DHEA-s (low)
- autoantibodies
What factors can affect serum cortisol levels (other than addison’s disease)?
- people working shifts (disrupts diurnal variation of cortisol)
- pregnancy
- oestrogen based medication (OCP/hormone replacement) - increases cortisol binding globulins increasing cortisol
- people on long term corticosteroids
Management for Addison’s disease
- 3mg daily prednisilone OR 15-25mg 3/daily hydrocortisone (replace cortisol)
- fludrocortisone (replace aldosterone)
- DHEA replacement (unlicensed)
What advice should be given to patients with Addison’s disease?
- have a steroid warning card
- carry emergency hydrocortisone
- wear a medic-alert bracelet (take double steroid dosage when ill)
Features of Addison’s crisis
- Hypotension
- Hypovolemic shock (dehydration)- tachycardia
- altered consciousness
- seizures/convulsions
- cardiac arrest (hyperkalemia)
- severe vomiting/diarrhoea
Management of Addison’s crisis
- IV fluid rehydration (replace Na+)
- IV bolus hydrocortisone
- dextrose to treat hypoglycaemia
- treat cause (ABs for infection)
- monitor (electrolyte levels/ vitals)
What is cushing syndrome ?
high levels of cortisol
Causes of Cushings syndrome
ACTH dependant
- cushings disease (adrenal hyperplasia due to pituitary adenoma)- trea
- ectopic ACTH production -small cell lung cancer)
ACTH- independant
- ORAL STEROIDS
- adrenal adenoma
- adrenal nodular hyperplasia
Presenting symptoms of Cushing’s syndrome
- increased weight
- mood change (depression)
- proximal weakness
- erectile dysfunction/ irregular menses
Examination findings of cushing’s syndrome
- central obesity
- moon face, red cheeks
- buffallo hump
- purple abdominal striae
- poor wound healing
- thin skin - bruises
- osteoporosis (thin bones)
Investigations for cushing’s syndrome
- Bloods- U&Es, high glucose
2, High-sensitivity tests:
- urinary free-cortisol
- late-night cortisol (usually only high in morning unless cushings)
- overnight dexamethasone suppression test
- low dose dexamethasone suppression tests
- CT/MRI of adrenals, measure ACTH => ACTH dependant
Pituitary MRI => ACTH independant
lung cancer? => CXR, bronchoscopy
Management of cushing’s syndrome
- stop steroids
- pre-surgery/ unfit
- metyrapone (11b-hydroxylase inhbitor)
- ketoconazole (17a-hydroxylase inhibitor => inhibitis cortisol/ aldosterone + sex-steroids)
- drugs for osteoporosis - surgery
- pituitary adenoma => trans-sphenoidal adenoma resection
- adrenal adenoma => surgical removal of tumour
Mechanism + Side effects of metyrapone
Inhibits 11 hydroxylase enzyme and inhibits cortisol production
- nausea, vomiting
- hypoadrenalism (low mineralcorticoids)
Mechanism + Side effects of ketoconazole
Inhibits 17a hydroxylase enzyme and inhibits cortisol (+ sex steroids) production
- nausea, vomiting
- alopecia
- liver damage
complications of cushing’s syndrome
- diabetes (high cortisol => high glucose)
- osteoporosis
- hypertension
- increased infection risk
prognosis for patients with cushing’s syndrome
untreated 5 yr survival - = 50%
Define thyrotoxicosis
abnormally high levels of thyroid hormones in blood due to problem with HPT axis (hypothalamus-pituitary-thyroid)
=> Hyperthyroidisim (subset of thyrotoxicosis)
- increased thyroid production from thyroid gland
Causes of thyrotoxicosis
- Graves disease
- Toxic multinodular goitre (from Plummer’s)
- Early phase Thyroiditis - de Quervains/ post-partum/ hashimoto’s (most common in elderly)
Thyroiditis causes stored thyroxine to be released from thyroid gland=> causing brief early hyperthyroidism but as stores get used up => hypothyroidism
Define Graves disease
autoimmune condition where anti-TSH antibodies bind to TSH receptors on thyroid gland and activate thyroid gland => increased T3/T4 production
Symptoms of Grave’s disease
- weight loss + increased appetite
- heat intolerance (hot)
- diarrhoea
- sweating
- tremor
- anxiety/ irritability
- oligo/amenorrhoea
- libido loss
- weakness
Examination signs of Grave’s
- palmar erythema
- sweaty hands
- thyroid acropachy (severe + painful finger/toe clubbing)
- fine tremor
- hair thinning
- exopthalmos
- opthalmoplegia (CN III,IV,VI palsy)
- lid lag
- goitre
- gynaecomastia
- tachycardia (AF most common arrythmia with thyrotoxicosis)
- pre-tibial myxoedema
Investigations of Grave’s
Bedside
- ECG
- glucose
Bloods
- TFTs (raised T3/T4, low TSH)
- FBC
- U&Es
- LFTs
- autoantibodies (anti-TPO, anti-TSH receptor, anti-thyroglobulin)
Imaging
- neck ultrasound
- radioiodine uptake scan
Management of acute thyroid storm
- IV fluids
- beta-blockers (for tachycardia)
- anti-thyroid drugs (propylthiouracil/ carbimazole)
- IV steroids (hydrocortisone)
- iodine/ pottassium iodide
Management of Grave’s (subacute)
First line:
- beta-blockers for tachycardia/anxiety/tremor/ palpitations + steroids-prednisilone
- anti-thyroid drugs (carbimazole/ propylthiouracil) => 1yr
- radioactive iodine
Surgery (usually in planning to get pregnant/ severe Graves/ ineffective first line/ suspect malignancy)
- Thyroidectomy
Mechanism of antithyroid drugs (thionamides => propylthiouracil, carbimazole)
- inhibit thyroid peroxidase enzyme
- inhibit iodination of iodine
- inhibit iodination of thyroglobulin => no thyroxine synthesis
Side effects= rashes, agranulocytes (SEVERE)
Complications of Grave’s
- AF => strokes/ heart attacks
- Congestive heart failure (elderly)
- Untreated => osteroporosis
- Elephantessis (RARE)
- Orbitopathy (RARE)
Define Plummer’s => toxic multinodular goitre
- benign tumour of thyroid gland => increased thyroxine production
- Unilateral lump on one side
- Radioactive iodine uptake on one side
Define thyrotoxic storm
Extreme and sudden thyrotoxicosis
Symptoms of thyrotoxic storm
- hyperpyrexia (fever)
- hypertension
- severe tachycardia (>140bpm)
- confusion/ delerium
- fainting
- jaundice, nausea, abdominal pain
Management of thyrotoxic storm
- IV fluids
- beta-blockers (for tachycardia)
- anti-thyroid drugs (propylthiouracil/ carbimazole)
- IV hydrocortisone
- URGENT endocrinology review
What can trigger thyrotoxic storm?
- INFECTION
- trauma
- thyroid surgery
- stroke
- diabetic ketoacidosis
- MI/ congestive heart failure
- radioactive iodine replacement
define hypothyroidism
syndrome caused by low levels of thyroid hormones (T3/T4)
Causes of primary hypothyroidism (low T3/T4 + high TSH)
- iodine deficiency (or XS)
- Hashimoto’s thyroiditis (AUTOIMMUNE)
- Post-surgery damage to thyroid gland (neck/thyroid)
- iatrogenic (anti-thyroid drugs, iodine, amiodarone)
- Transcient thyroiditis (de Quervains/viral, Post-partum)
causes of secondary hypothyroidism (low T3/T4 + low TSH)
pituitary dysfunction due to:
- tumours
- surgery/ trauma
- pituitary infarction
- infiltration (amyloidosis, sarcoidosis, haemachromotosis, TB)
- Sheehan’s syndrome (pituitary necrosis due to post-partum haemorrhage)
- drugs (cocaine, dopamine, glucocorticoids, metformin)
presenting symptoms of hypothyroidism
*everything slows down
- slower metabolism=> weight gain
- bradycardia
- cold intolerance
- fatigue
- constipation
- dry skin/ hair loss
- weakness
- depression, impaired concentration
- menstrual irregularities
+ for secondary hypothyroidism
- recurrent headaches/ vision changes
- changes to other pituitary hormone levels- skin depigmentation (ACTH), galactorrhea (prolactin), erectile dysfunction/amennorrhea (LH/FSH), acromegaly (GH)
examination findings of hypothyroidism
- hands (cold, bradycardia)
- head/neck/ arms (puffy face, goitre, oedema, hair loss, dry skin, vitiligo, Thyroid pain (subacute thyroiditis)
- chest (pericardial effusion, pleural effusion)
- abdominal (ascites)
- neurological (reduced deep tendon reflexes, signs of carpal tunnel)
What is myxoedema coma + symptoms:
severe hypothyroidism seen in the elderly
- hypothermia
- hypoventilation
- hyponatremia
- heart failure
- confusion
- coma
investigations + findings for hypothyroidism
Bloods
- Thyroid function tests (low T3/T4 +/- low TSH)
- FBC + serum b12 ( check for associated normacytic anaemia)
- U&Es- may have low sodium
- high cholesterol (check for associated dyslipidaemia)
- glycated HbA1c (check for associated diabetes)
- check for coeliac disease (anti-transglutaminase antibody)
- serum thyroid peroxidase antibodies (for autoimmune disease)
- ultrasound of neck (look at goitre)
Management of hypothyroidism
- hypothyroidism => 50-100ug levothyroxine daily before food + monitor TSH (to normalise) every 3 months and adjust dose
*in secondary hypothyroidism monitor using free T4 levels - hypothyroidism during pregnancy- need higher levothyroxine dose to prevent neonatal complications (monitor TFTs more frequently)
why can the thyroid function tests still be abnormal in (suspected) hypothyroidism after adequate levothyroxine treatment
- poor drug compliance (side effects)
- interacting with other drugs
- malabsorption of levothyroxine in gut (coeliac, pernicious anaemia, H. pylori gastritis, atrophic gastritis, IBD)
- increased LT4 demands (weight gain/ pregnancy)
- foods that reduce LT4 absorption (grapefruit, coffee, milk, soya)
Why does adrenal insufficiency need to be ruled out before prescribing levothyroxine?
as it can precipitate Addison’s crisis
Management of myxoedema coma
- oxygen
- rewarming
- rehydration
- IV T3 (faster action onset than T4)
- IV hydrocortisone (for adrenocortical insufficiency)
- treat underlying cause (e.g. infection)
complications of hypothyroidism
- myxoedema coma (80% mortality rate)
- myxoedema madness (+ delusions/ psychosis)
Define hyperparathyroidism
XS production of PTH (by chief cells of parathyroid gland)
- Primary - high PTH regardless of calcium levels (high Ca2+)
- Secondary - high PTH in response to hypocalcemia (low Ca2+)
- Tertiary- increased PTH in response to inital hypocalcemia, then autonomous secretion of PTH
Causes of hyperparathyroidism
Primary (high PTH)
- parathyroid adenoma (80%)
- parathyroid hyperplasia
- parathyroid carcinoma
- MEN syndromes
Secondary (low Ca2+ => high PTH)
- chronic renal failure
- Vit. D deficiency
Presenting symptoms of hyperparathyroidism (hypercalcemia)
Primary
- bone pain
- renal calculi
- abdominal pain, nausea, constipation, dyspepsia, anorexia
- pscyhcic groans (depression, fatigue, impaired concentration)
- polyuria, polydypsia
- lethargy
- pancreatitis, duodenal ulcers??
Secondary
- could present with hypocalcemia signs (Convulsions, arrhytmias, tetany, parasthesia)
Investigations for hyperparathyroidism
Bloods
- U&Es- albumin
- PTH (high)
- serum calcium
- serum phosphate (low)
- LFTs- ALP
- Vit D
- calcium: creatinine ratio- differentiates primary hyperparathyroidism with familial hypercalciuric hypercalcemia (FHH)
Imaging
- renal USS - check for stones
Management of hyperparathyroidism
Primary
- IV fluids
- moderate calcium/ vit D intake
- avoid thiazide diuretics (worsens hypercalcemia)
- Surgery - partial/total parathyroidectomy
Secondary
- treat cause- renal failure (dialysis?) / vit D deficiency (Ca2+/ Vit D supplements)
Complications of hyperparathyroidism
- Primary => increased bone resporption, increased calcium reabsorption => HYPERCALCEMIA
- Secondary => stimulates osteoclasts => osteitis fibrosa cystitis
- Post-surgery => hypoPTH, hypoCa2+, hoarse voice (reccurent laryngeal nerve damage),
Define hypoparathyroidism
low pTH production
- Primary - Low pTH => low Ca2+
- Secondary - high Ca2+ => low PTH
Causes of hypoparathyroidism
Primary (low PTH, low Ca2+)
- trauma
- parathyroidectomy
- thyroidectomy
- hypomagnesium- chronic alcohol intake, XS diarrhoea, poor nutrition/ malabsoprtion
- genetic mutations in CASR, GATA3
Secondary (high Ca2+ => low PTH)
- malignancy (bone metastasis, multiple myeloma, lung Squamous CC)
- thiazide diuretics
- XS vit D (high calcitriol)
- sarcoidosis
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Presenting symptoms of hypoparathyroidism
Primary -hypocalcemia
Secondary - hypercalcemia
Primary (low PTH => low Ca2+)
- Convulsions
- Arrhytmias
- Tetany
- Parasthesia
Examination findings of primary hypoparathyroidism (hypocalcemia)
- Chovostek’s sign (ipsilateral facial twitch when cheek touched)
- Trousseau’s sign (blood pressure cuff inflates, cause carpopedal spasm)
Investigations for hypoparathyroidism
Bedside
- ECG- prolonged QT interval (arrythmias)
Bloods
- U&Es- albumin, creatinine (normal- unless renal failure)
- serum calcium (low)
- serum phosphorous
- serum magnesium (low)
- serum PTH (low)
- Vit D (low)
- LFTs- ALP
- FBC
IMaging
- renal imaging
Management of hypoparathyroidism
Primary (low PTH => low Ca2+)
- Ca2+ / Mg2+ supplements
- recombinant PTH
- calcitirol supplements
- thiazide diuretics (reduce the rate of urinary calcium excretion )
- reduce PPI/Corticosteroids (reduce Ca2+ absorption), loop diuretics (increase Ca2+ excretion)
Secondary (high Ca2+ => low PTH)
- treat cause
- moderate Ca2+/ Vit D
- reduce thiazide diuretics (worsen hypercalcemia)
Complications of hypoparathyroidism
- hypocalcemia (CATs NUMB)
- increased phosphate reabsorption
- cataracts
- renal stones/ insufficiency (hypercalcemia?)
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