Week 5: Endocrine (2) Flashcards

Question

treatment of hyperthyroidism

Answer 1

**Medication** * Carbimazole * Beware of agranulocytosis (reduces neutrophils) * Beta blocker for symptom control **Surgery** * If side effects on medication or patient preference * Good cosmetic results * Small risk of laryngeal nerves palsy’s and hypocalcaemia **Radioactive iodine** * Good definitive non-surgical option * Contra-indicated in pregnancy * Radiation restriction guidance after treatment

Answer 2

thyroid crisis hyperthyroidism and pregnancy

Answer 3

* Rare condition with 10% mortality * Hyperpyrexia * Tachycardia * Cardiac failure * Liver dysfunction * Urgent treatment

Answer 4

* In graves disease antibodies can cross placenta * Baby can be born with hyperthyroidism * Requires close monitoring in pregnancy

Answer 5

**Diffuse goitre** * Simple goitre * Auto-immune * Thyroiditis **Nodular goitre** * Multinodular goitre * solitary nodule (red flag ) **Fibrotic goitre** * Riedel’s thyroiditis – rare * **Iodine deficiency** * Common worldwide * Rare in UK

Answer 6

* Very young or old patient * Rapid enlargement of lump in neck * Hoarse voice and dysphagia * Family history of thyroid cancer

Answer 7

* Hard irregular thyroid mass * Fixed to surrounding structures * Cervical lymph nodes

Answer 8

* Thyroid ultra-sound * Fine need aspiration * CT scan thorax and mediastinum

Answer 9

surgical removale MUST BE DONE BY EXPERT TO PREVENT DAMAGE TO THE PARATHYROID GLANDS AND NOT DAMAGE TO THE RECURRENT LARYNGEAL NERVE -→ PALSY

Answer 10

* Pyramidal shape * Sits on top of the kidney * made up of cortex and medulla SALT SUGAR SEX (DEEPER YOU GET THE SWEETER)

Answer 11

GFR zona glomerulosa zona fasiculata zona reticularis

Answer 12

* Salt and water * Mineralocorticoids e.g. aldosterone * Regulated by RAAS * RAAS: In response to low circulating blood volume, hyponatraemia or hyperkalaemia, renin is activated to catalyse the conversion of angiotensinogen to angiotensin I, which is converted by angiotensin-converting enzyme (ACE) to angiotensin II. Angiotensin II stimulates aldosterone release upon binding to the angiotensin receptor. Aldosterone acts mainly at the renal distal convoluted tubule on its receptor to cause sodium retention and potassium loss.

Answer 13

* Sugar * Glucocorticoids- cortisol * Cortisol synthesis is regulated by ACTH * Cortisol exerts a negative feedback on the hypothalamus top reduce CRH (and vasopressin) and on the anterior pituitary to reduce ACTH * Cortisol is highest at 0800 and lowest midnight * Investigation- cortisol immunoassays measure total (bound and free) cortisol, hence conditions which stimulate CBG (capillary blood glucose) e,g. oestrogen therapy, may increase measure cortisol levels without affecting biologically active free levels

Answer 14

* Sex * Androgens- Testosterone * Controlled by ACTH * More important role in women (in both sexes pre-pubertally), as adult men rely mainly on testicular production of androgens * DHEA and DHEA-S and androstenedione are converted to more potent testosterone and dihydrotestosterone in peripheral tissue * Androgens exert their effect on: sebaceous glands, hair follicles, the prostate gland and external genitalia

Answer 15

**Presentation of adrenal medulla disease (noradrenaline/ adrenaline)** * Excessive catecholamine secretion * Acute episodes * Sweating * Palpitations * High or low BP * Collapse * SUDDEN DEATH

Answer 16

* **24 hour** **urine** ***catecholamines*** * *adrenaline (short half life)* * *noradrenaline (short half lif)* * *dopamine etc* Measuring 24 hour urine ***catecholamines*** gives an idea of how much ***adrenaline*** is being secreted by the tumour over the 24 hour period. *or* * **Plasma free** ***metanephrines*** * *metanephrines are breakdown products of catecholamine- longer half life- therefore more reliable diagnostic tool* * Avoid certain foods: coffee, coke, bananas, chocolate, vanilla

Answer 17

* **Cortisol (lack of glucocorticoid) deficiency (addisons disease) -** weakness, tiredness, weight loss, hypoglycaemia * Cortisol does the opposite to insulin * **Mineralocorticoid (aldosterone) deficiency–** dizziness, hypotension, low Na, high K * **Androgen deficiency– e.g. Addisons** * **In women-** low libido and loss of body hair in women * Testosterone only produced in adrenal gland in women * **In men-** no symptoms because produced in testicals

Answer 18

* **Cortisol excess-** weight gain and cushingoid features (cushing’s syndrome) * Diabetes * Bone weakness * **Mineralocorticoid excess (aldosterone)-** high BP and low K * **Androgen excess –** increased male characteristics in women

Answer 19

* Skin pigmentation due to melanocyte stimulation * Pigmentation seen in Addisons and ACTH- driven cushings

Answer 20

* Measurement of cortisol and ACTH * Measurement of 24hr urinary excretion of cortisol and its breakdown products * Dynamic function tests * Dexamethasone suppression test * Suppression of plasma cortisol by \>50% is characteristic of Cushing’s disease, but suppression doesn’t normally occur in adrenal tumour or ectopic ACTH production * ACTH stimulation test * Admission of **Synacthen** would normally increase plasma cortisol, and a normal response to this usually excludes Addison’s disease * CT * MRI * Functional imaging: MIBG scan * PET scan

Answer 21

A condition in which there is excessive production of aldosterone.

Answer 22

excess aldosterone production due to a defect in the adrenal cortex. Commonest form of endocrine hypertension. 1. Bilateral idiopathic adrenal hyperplasia 2. Or Aldosterone-secreting adenoma (Conns syndrome)

Answer 23

* Hypertension and **hypokalaemia** * Elevated aldosterone independent of RAAS (suppressed renin) * Scan- shows adrenal adenoma or bilateral hyperplasia

Answer 24

excess aldosterone production due to overactivity of the RAAS * Renin- producing tumour or renal artery stenosis

Answer 25

* High blood pressure * Left ventricular hypertrophy * Stroke * Hypernatremia * Hypokalaemia

Answer 26

* Dependent on cause * Surgical treatment for aldosterone-secreting adenomas or * Spironolactone (a mineralocorticoid receptor agonists) can be used for other causes

Answer 27

A syndrome caused by excessive exposure to cortisol → different to disease

Answer 28

exogenous endogenous

Answer 29

main cause is being prescribed glucocorticoids e.g. being prescribed dexamethasone

Answer 30

* **Cushing’s disease:** benign ***pituitary adenoma*** that secretes ACTH * **Adrenal cushing’s:** Adrenal tumour secreting glucocorticoids * Non- pituitary-adrenal tumours producing ACTH and/ or CRH (e.g. small cell lung cancer- very rare)

Answer 31

* Moon shaped face * Buffalo hump * Abdominal obesity * Striae * Acute weight gain * Hyperglycaemia – increased gluconeogenesis * Hypertension- mineralocorticoid effects of excess cortisol

Answer 32

(e.g. prednisolone and dexamethasone) are the same as the effects of higher levels of cortisol. → steroid dosage should always be decreased gradually and never stopped suddenly

Answer 33

adrenal tumour * ACTH is suppressed- ACTH independent * Unlike pituitary and ectopic ACTH * **Symptoms** * Androgenic symptoms may be present * Hirsutism * Acne * Greasy skin * Virilising features in large tumours * Androgenic alopecia * Deep voice * Clitoromegaly * **Treatment** * Adrenalectomy- laparoscopic * Large tumours need open surgery

Answer 34

Androgens are partially regulated by ACTH and CRH. * Promote axillary and pubic hair growth in both males and females

Answer 35

* In prepubescent males dehydroepiandrosterone (DHEA) released from the adrenal glands is converted to testosterone in the testes. * After puberty this production is insignificant as the testes themselves release testosterone

Answer 36

* Adrenal androgens promote libido and are converted to oestrogen in tissues * After menopause this is the only source of oestrogen in the body

Answer 37

**a rare condition in which an infant's external genitals don't appear to be clearly either male or female**. * Genetic defect- deficiency of the 21-hydroxylase enzyme * Results in decreased glucocorticoid and mineralocorticoid production * Precursor of these hormones- 17a-hydroxypregnenolone is therefore diverted to more androgen synthesis (e.g. testosterone)-→ **excessive testosterone** * Can also cause **salt wasting crises- high rate of sodium lost**

Answer 38

*‘Primary adrenal insufficiency”* Hypocortisolism

Answer 39

* Destructive atrophy of the adrenal glands by autoimmune response * Fungal infections * Adrenal cancer * Adrenal haemorrhage * TB (in old times- good time lol)

Answer 40

* Postural hypotension * Lethargy * Weight loss * Anorexia * Increased skin pigmentation hypoglycaemia

Answer 41

* Decrease in cortisol * Reduced negative feedback on the anterior pituitary * More POMC produced to synthesis ACTH * POMC also produces alpha-MSH * Increase in MSH= increase in melanin synthesis- hyperpigmentation * ACTH can also activate melanocortin receptors on melanocytes- hyperpigmentation

Answer 42

* Lifelong replacement * Glucocorticoid: hydrocortisone, prednisolone * Mineralocorticoid: fludrocortisone * Education * Double dose of glucocorticoid at time of illness * Emergency HC injection if vomiting * Steroid card and bracelet

Answer 43

Life threatening emergency due to adrenal insufficiency

Answer 44

* Abrupt steroid drug withdrawal * Severe stress * Salt depravation * Infection * Trauma * Cold exposure * Over exertion

Answer 45

**Signs and symptoms** * Collapse * Nausea * Vomiting * Pyrexia * Hypotension * Vascular collapse

Answer 46

fluid replacement and cortisol

Answer 47

Congenital adrenal hyperplasia (CAH) is a group of rare inherited **autosomal recessive disorders** characterized by a deficiency of one of the enzymes needed to make specific hormones. * CAH effects the adrenal glands located at the top of each kidney. * Normally, the adrenal glands are responsible for producing three different hormones: * 1. corticosteroids, which gauge the body's response to illness or injury; * 2. mineralocorticoids, which regulate salt and water levels; and * 3. androgens, which are male sex hormones. * An enzyme deficiency will make the body unable to produce one or more of these hormones, which in turn will result in the overproduction of another type of hormone precursor in order to compensate for the loss.

Answer 48

enzyme 21-hydroxylase

Answer 49

adrenal crisis and ambigious genitalia

Answer 50

* Block in adrenal cortex pathway * Presentation depends on enzyme defect * Lack of enzyme leads to: * Low cortisol and aldosterone * High male hormones (androgens)

Answer 51

**Presentation** * Hypotension * Hyponatraemia * Hyperkalaemia * Hypoglycaemia * Virilisation – development of male body parts

Answer 52

**Pheochromocytoma and paraganglioma**

Answer 53

**a type of neuroendocrine tumor** that grows from cells called chromaffin cells. These cells produce hormones needed for the body and are found in the adrenal glands. The adrenal glands are small organs located in the upper region of the abdomen on top of the kidneys. * Acute episodes * Sweating * Panic attacks * Palpitations * High or low BP * Collapse **Acute crisis** * Hypertensive crisis * Encephalopathy * Hyperglycaemia * Cardiac arrhythmias * Sudden death

Answer 54

* 24h urine metanephrines * 2-3 x collections needed * Plasma metanephrine * Neuro-endocrine marker: Chromogranin A

Answer 55

* Alpha blockade- phenoxybenzamine * Always do alpha-block before b-block * B blockade- bisoprolol * Surgical excision * Perioperative management * Specialist anaesthetic team * Risk of crisis during operation * Maximal vasodilation and filling with IV fluids

Answer 56

Unopposed alpha stimulation can cause hypertensive crisis