Endocrinology Flashcards
Cushings disease
Raised cortisol level specifically due to raised ACTH from a pituitary tumour
Cushings syndrome is due to? (2)
Excess cortisol
Excess ACTH -> raised cortisol
C U S H I N G (mneumonic)
Central obesity / Comedones Urinary free cortisol Straiae Hirutuism Immunodeficiency Neoplasms Glucose (raised)
Cushings caused by raised cortisol (2)
Steroids
Adrenal carcinoma / adenoma
Cushings caised by raised ACTH
Tumour producing ACTH (not pituitary) e.g. Small cell lung cancer
Cushings disease
Cause of pseudocushings
alcohol excess
Dexamethasone suppression test result meanings
Low dose High dose
Cortisol dec Cortisol dec
No change Cortisol dec
No change No change
No pathology - dex suppresses cortisol
Cushings disease - high levels able to suppress excess ACTH
Cushings syndrome - levels of cortisol are high INDEPENDENT of ACTH
causes of false +ve dex suppression test
obesity
alcoholism
chronic renal failure
Screening test for cushings
urine cortisol
3 complications of cushings
cardiac problems
diabetes
osteoporosis
Specific clinical presenting feature of cushings disease
hyperpigmentation as ACTH activates melanocytes
Action of aldosterone
Increased sodium and water reabs
Increase K+ secretion
Commonest cause of primary aldosteronism
Conns syndrome - aldosterone producing adenoma
Symptoms of hypokalaemia
cramps
abdo pain
muscle weakness
polyuria and polydipsia
Signs of hyperaldosteronism
fluid overload
hypertension
metabolic acidosis
Treatment of primary hyperaldosteronism
Aldosterone agonist e.g. spironolactone
Calcium channel blockers
Causes of primary aldosteronism
Conns syndrome
Adrenal carcinoma
Adrenal hyperplasia
Pathophysiology of secondary aldosteronism
Increased renin causing increased aldosterone levels
Causes of secondary aldosteronism
Renal artery stenosis Chronic oedema Cardiac failure Liver failure Hypertension
Levels of renin in
1) Primary hyperaldosteronism
2) Secondary hyperaldosteronism
LOW
HIGH
Treatments of hyperaldosteronism
Aldosterone antagonist
Pathophysiology of primary hypoadrenalism (addisons)
Low levels of all adrenal hormones due to acute adrenal destruction
Addisons crisis - patients usually present with one of two conditions
Hypoglycaemia
Hypovolaemic shock
Most common cause of addisons disease
Autoimmune destruction of the adrenal glands
Signs and symptoms of low cortisol
Hyperpigmentation
Hypoglycaemia
Signs and symptoms of low aldosterone
Hyponatraemia
Hyperkalaemia
Hypotension - due to fluid and Na+ loss
Signs and symptoms of low androgens
Lack of pubic hair in females
Generalised unwell symptoms
Addisons crisis features
Abdo pain Vomiting Hypotension Tachycardia Hypovolaemic shock Collapse
Important hx to ask if suspect addisions?
steroid use?
Key test to help diagnose addisons
synacthen test
Short synacthen test result - cortisol not raised
Long synacthen test result - cortisol not raised
Primary hypoadrenalism
Short synacthen test result - cortisol not raised
Long synacthen test result - cortisol raised
Seconary hypoadrenalism
Short synacthen test result - cortisol raised
Long synacthen test result - cortisol raised
NORMAL
SE of steroids
B E C L O M E T H A S O N E
Buffalo hump Easy bruising Cateracts Large appetite Obesity Moon face Euphoria Thin arms / legs / skin Hypertension / hyperglycaemia Avascular necrosis of femoral head Skin thinning Osteoporosis Negative nitrogen balance Emotional liability
Pathophysiology of secondary hypoadrenalism
Dysfuction of hypothalamus, pituitary axis
Main causes of secondary hypoadrenalism (2)
Iatrogenic - long term steroid use
Pituitary / hypothalamus tumour / infection / infarction
Difference between sign and symptoms of primary and secondary hypodrenalism
Secondary
ACTH low - so no hyperpigmentation
Aldosterone not low so no electrolyte imbalance
ACTH levels in
1) Primary hypoadrenalism
2) Secondary hypoadrenalism
HIGH
LOW
When should a new drug be added in T2D treatment (HbA1c)
> 58
T2D diagnosis criteria
If the patient is symptomatic:
fasting glucose greater than or equal to 7.0 mmol/l
random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
If the patient is asymptomatic the above criteria apply but must be demonstrated on two separate occasions.
Hyperparathyroidism leads to
Ca2+ levels to…?
PO4 levels to…?
High
Low
6 key features of hypercalcaemia
Renal stones Abdominal groans - pain Polydypsia Bones (bone pain) Psychiatric overtones - depression
Impact of hypercalcaemia on the ECG
shortened QT
Most cases of primary hyperparathyroidism are due to?
parathyroid adenoma
Primary hyperparathyroidism
Ca2+ results
PTH result
high
high
Main therapy in hypercalcaemia
fluid rehydration
Secondary hyperparathyroidism
Ca2+ results
PTH results
low
high
Two causes of secondary hyperparathyrodism
renal failure
low vit d
tertiary hyperparathyrodism
prolonged secondary so PTH becomes so high, calcium is produced at a v high level. Vit D must be corrected
Increased Ca2+
Vit D normal
PTH high
Clinical signs of hypocalcaemia
pins and needles
muscle aches
tetany
chvostek’s sign - twitching of facial muscles when the facial nerve is tapped
Arrhythmias
Blood tests in hypocalcaemia
Ca2+ PTH Vit D Phosphate Magnesium U&Es
Most common cause of hypoparathyroidism
iatrogenic - removal during thyroidecomy / post radiation
pseudohypoparathyrodism is due to?
resistance to PTH
Impaired glucose tolerance
Fasting glucose -
2h post glucose load
- 0 - 7.0
7. 8 - 11.0
Presentation of T1D
Age 12
Polydypsia
Polyuria
+/- ketoacidosis
Tests in suspected T1D
FBC
Glucose - HbA1C
U&Es
Urine dip - ketone / glucose
What other organs should be monitored in diabetes
Eyes
Renal
Vascular
Precipitants of diabetic ketoacidosis
Sepsis
Not taking insulin
MI
Presentation of ketoacidosis
N&V Confusion Abdo pain Lethargy Tachypnoea