Adrenals Flashcards
What is made in adrenal glomerulosa
Mineralocorticoids
What is made in adrenal fasciculata
Glucocorticoids
What is made in adrenal reticularis
Sex steroids
What is made in adrenal medulla
Adrenaline
Noradrenaline
Which part of the adrenal makes mineralocorticoids
Mineralocorticoids
Which part of the adrenal makes glucocorticoids
Fasciculata
Which part of the adrenal makes sex steroids
Reticularis
Which part of the adrenal makes catecholamines
Medulla
4 causes of primary hyperaldosteronism
Adrenal adenoma: Conn’s syndrome (70%) Bilateral adrenal cortex hyperplasia (30%) Familial hyperaldosteronism RARE: Aldosterone producing adrenal carcinoma
What is the normal population of Conns
young females
What is the normal population of bilateral hyperaldosteronism
older males
Symptoms of hypokalaemia that may be present in hyperaldosteronism (4)
Muscle weakness/cramps
Polyuria/nocturia
Paraesthesia
Mood disturbances/letharfy
Signs of hyperaldosteronism
HYPERTENSION (HTN)
Difficult to control with antihypertensive medications
Complications of hypertension e.g retinopathy of hypertension, headaches
Main 4 Ix for primary hyperaldosteronism
Plasma K+ levels Low in 20% of patients Urine K+ - high Plasma aldosterone - high Plasma aldosterone:renin ratio – high
How to confirm primary hyperaldosteronism
Failure of aldo suppression post fludrocortisone salt load – confirms 1’ hyperaldosteronism
Mx of hyperaldosteronism by cause (2)
Adrenal adenoma
Adrenalectomy (laparoscopic)
Bilateral adrenal hyperplasia (or those not fit for/don’t want surgery)
Spironolactone (aldosterone inhibitor)
Eplerenone if side effects not tolerated
Monitor serum K+, creatinine and BP
SE of spironolactone (3)
gynaecomastia, impotence, muscle cramps
Most common cause of Cushing’s syndrome
steroid exposure
5 ways of acquiring Cushing’s syndrome endogenously
ACTH-dependent (80%)
Excess ACTH from pituitary adenoma (Cushing’s disease)
Ectopic ACTH e.g lung tumour, pulmonary carcinoid tumour
ACTH-independent (20%)
Benign adrenal adenoma
Bilateral adrenal hyperplasia
Adrenal carcinoma (rare)
Ix for Cushing’s disease (5)
Serum glucose – high risk diabetes Pregnancy test Overnight dexamethasone suppression test Low-dose dexamethasone suppression test High dose
What is the use of the HD dexamethasone suppression test and explain
Differentiate between CD and CS
High dose suppresses cortisol –> pituitary adenoma
High dose doesn’t suppress cortisol –> ectopic (lung) or adrenal pathology
Normal population of Cushing’s syndrome (age and gender)
W:M = 4:1
20-40yrs
Mx of Cushing’s (medical 2 and surgical)
MEDICAL
Metyrapone/ketoconazole – inhibit cortisol synthesis
Use pre-operatively or if unfit for surgery
SURGICAL – preferred treatment
Pituitary adenoma: trans-sphenoidal resection of adenoma
Adrenal adenoma/carcinoma: surgery to remove
Ectopic ACTH: treatment directed at tumour
Complications of Cushing’s (4)
Diabetes
Osteoporosis
Hypertension
Pre-disposition to infections
Prognosis of Cushing’s
untreated, 5yr survival rate is 50%.
Depression often persists for years following successful treatment
What is an adrenal paraganglioma
Extra-adrenal tumour of the adrenal medulla
Common triad in phaeochromocytoma
“Palpitations
Headaches
Episodic sweating”
3 familial syndromes that can result in phaeochromocytomas
“Multiple Endocrine Neoplasia 2a (MEN2a)
Von Hippel Lindau syndrome (VHL)
Neurofibromatosis type 1 (NF1)”
Which group of patients should you consider phaeos in
Consider phaeos in patients with young-onset or resistant intractable hypertension
Ix for phaeochromocytomas (5)
“24 hr urine collection - check for catecholamines, metanephrines + normetanephrines
Plasma free metanephrines/normetanephrines
Genetic testing
Tumour localisation:
CT > MRI
I-123 MIBG scintigraphy”
What is primary adrenal insufficiency also known as
Addisons disease
What is primary adrenal insufficiency also known as
Pituitary or hypothalamic disease hits decreased ACTH secretion
Inherited causes of adrenal insufficiency (2)
Adrenoleukodystrophy
ACTH receptor mutation
Iatrogenic causes of adrenal insufficiency (2)
Sudden cessation of long-term steroid therapy
After bilateral adrenalectomy
Infectious causes of adrenal insufficiency (3)
"TB Meningococcal septicaemia (Waterhouse-Friderichsen Syndrome); CMV ; Histoplasmosis"
Ways of acquiring adrenal insufficiency (6)
Autoimmune Infections Infiltration Infarction Inherited Iatrogenic
What can cause infiltrative adrenal insufficiency (5)
metastasis (mainly from lung, breast, melanoma); Lymphomas; Amyloidosis
Which cancers metastasise to adrenals commonly
Which cancers metastasise to adrenals commonly
Signs of Addisons (4)
Increased pigmentation
Postural hypotension
Loss of body hair in women (androgen deficiency)
Associated autoimmune condition (e.g. vitiligo)
Symptoms of Addisons (7)
"Symptoms: VAGUE and NON-SPECIFIC Fatigue Weakness Myalgia Weight loss (+anorexia) Diarrhoea and Vomiting Abdominal pain Depression "
Pathophysiology behind acute Addisonian crisis (4 ways)
“Defective production of aldosterone causes increases water and salt loss, leading to hyponatraemia and hypovolaemia. Hyperkalaemia also occurs leading irregular heart rhythm which can lead to cardiac arrest.
Defective production of cortisol leads to liver function decreasing and so hypoglycaemia leading to seizures, convulsions and loss of consciousness.
Lack of cortisol leads to nausea and vomiting and diarrhoea and cramps leading to hypovolaemia which is exacerbated by the lack of aldosterone causing hypotension leading to shock, coma, organ failure and death.”
Sign of acute adrenal insufficiency (4)
Vomiting, diarrhoea, low blood pressure and
precipitated by stress
Ix for adrenal insufficiency (5)
Confirm diagnosis: 9am serum cortisol <100nmol/L Short SynACTHen test Serum cortisol <550 nmol/L at 30 mins
Long SynACTHen test
Autoantibodies
Abdo CT/MRI
Ix for acute Addisonian crisis (7 but 4 main ones)
"FBC U+Es High urea Low sodium High potassium CRP/ESR Low glucose Blood cultures Urinalysis Culture + sensitivity"
Mx of acute Addisonian crisis (3)
Rapid IV fluid rehydration
50ml 50% dextrose
IV 200mg hydrocortisone bolus
100mg 6hrly hydrocortisone till BP stable
Treat precipitating cause e.g Abx for infection
MONITOR
Mx of Addisons disease (2)
Replace:
GCs with hydrocortisone (TDS) increase dose in times of acute illness/stress
MCs with fludrocortisone
Changes to the ECG in moderate and severe 2 hypokalaemia
Moderate
Flattened T wave
Severe
ST depression
U wave
Changes to the ECG in moderate 2 and severe 2 hyperkalaemia
Moderate
Peaked T wave
ST depression
Severe
Widened QRS
Loss of P wave
Causes of systemic potassium release (2)
rhabdomyolysis, metabolic acidosis (e.g DKA)
Clinical features of hyperkalaemia (2)
Muscle weakness
ECG changes life-threatening arrhythmia
Mx of hyperkalaemia (5)
Management – 10 10 10 50 50
10ml 10% calcium gluconate 10U Actrapid 50ml 50% glucose Nebulised salbutamol 12-lead ECG (continuous)
Causes of hypokalaemia (4)
GI loss – vomiting, diarrhoea
Redistribution of K+ into cells – insulin, B-agonists, metabolic alkalosis
Renal loss – hyperaldosteronism, excess cortisol, natriuresis
Decreased K+ intake – anorexia nervosa
Clinical features of hypokalaemia (3)
Muscle weakness & spasm
Cardiac arrhythmia
Polyuria and polydipsia (nephrogenic DI)
Mx of hypokalaemia (3)
Management – always correct magnesium K+ 3.0-3.5 mmol/L Oral potassium chloride (SandoK) Recheck in 48 hours K+ <3.0 mmol/L IV potassium chloride Max infusion rate 10 mmol/hr (peripheral irritant)
3 main features of PCOS
Clinical features of hyperandrogenism Hirsutism Acne Oligo/amenorrhoea Polycystic ovaries on USS
Associations of PCOS (5)
Obesity Insulin resistance Type 2 DM Infertility Endometrial cancer
Aetiology of PCOS
Hyperinsulinaemia: increased ovarian androgen synthesis and reduced hepatic sex hormone binding globulin synthesis
Leads to an increase in free androgens (which gives rise to the symptoms)
Signs of PCOS (3)
High BMI
Hirsutism
Acanthosis nigricans
Symptoms of PCOS (3)
Menstrual irregularities Acne Male-pattern hair loss Weight gain Infertility
Blood test results for PCOS (6)
High LH
High LH:FSH ratio
High testosterone, androstenedione and DHEA-S
Low sex hormone binding globulin
Ix for PCOS
Bloods looking at sex hormones
Transvaginal USS
Ways of acquiring hyperkalaemia (5)
Renal disease – HTN, DM Low RAAS activity – ACE-Is, ARBs, aldosterone antagonists, adrenal failure Systemic K+ release - rhabdomyolysis, metabolic acidosis (e.g DKA) Damage to the DCT - type 4 renal tubular acidosis, NSAID toxicity Spurious sample (recheck)
