Endo Flashcards
What are the symptoms of hyperprolactinaemia in women?
Amenorrhea, galactorrhea, infertility, [compression symptoms]
What are the symptoms of hyperprolactinaemia in men?
Hypogonadism, reduced libido, erectile dysfunction, gynaecomastia, galactorrhea [compression symptoms]
Often late presentation: osteoporosis, atherosclerosis - indirect results of hypogonadism)
How do prolactin levels help determine cause of endo pathology?
Hypothalamic: prolactin rises
Hypopituitarism: prolactin falls
What is the size of a macroadenoma?
> 1cm
What is the most common functioning adenoma?
Prolactinoma
How do non-functioning adenomas present?
Compression symptoms: headache, vision problems (bitemporal hemianopia or upper temporal quadrantanopia) N+V, cranial nerve palsies
What is Sheehan’s syndrome?
Panhypopituitarism following massive obstetric haemorrhage (leading to infarction)
What is pituitary apoplexy?
Infarction or haemorrhage of pituitary tumour (eg from HTN or major surgery)
What are the symptoms of pituitary apoplexy?
Severe thunder-clap retro-orbital headache, N&V, reduced GCS, ophthalmoplegia + bitemporal hemianopia
What is the principle for testing HYPERpituitarism?
Suppression tests (i.e. not suppressed)
What is the principle for testing HYPOpituitarism?
Stimulation tests (i.e. not stimulated)
What is the test for excessive growth hormone?
Oral GTT (+VE: doesn’t suppress)
What is the test for excessive ACTH or CRH?
Dexamethasone (+VE: doesn’t suppress)
What is the test for insufficient GH?
Insulin tolerance (+VE: doesn’t stimulate it)
What is the test for insufficient cortisol?
Synacthen (ACTH analogue) (+VE: doesn’t stimulate it)
What is the test for insufficient GnRH?
Clomifene or LH/FSH (+VE: doesn’t stimulate it)
What are the typical lab findings in diabetes insipidus?
Increased plasma osmolality, decreased urine osmolality
What is the test to differentiate between cranial and nephrogenic DI?
ADH stimulation:
will correct cranial DI
no effect on nephrogenic DI
What are the typical lab findings in SIADH?
Decreased plasma osmolality, increased urine osmolality
Often euvolaemic and normotensive
What is the relationship between dopamine and prolactin?
Dopamine inhibits prolactin
What are physiological causes of hyperprolactinaemia?
Pregnancy
Puerperium
Breast stimulation
Stress
What are intra-cranial causes of hyperprolactinaemia?
Pituitary tumours Tumours compressing the pituitary stalk Head injury Brain surgery or radiotherapy Post-ictal
What are endocrine and metabolic causes of hyperprolactinaemia?
Hypothyroidism (because increased TRH)
Cushing’s syndrome
Cirrhosis of liver
PCOS
Which drugs cause hyperprolactinaemia?
Drugs that block dopamine receptors: domperidone, metoclopramide, neuroleptics, anti-psychotics
Dopamine-depleting agents: methyldopa
Anti-depressants
(+ many more)
What are the initial investigations for hyperprolactinaemia?
Exclude pregnancy
Basal serum prolactin (if mildly elevated: repeat, if excessively high: likely prolactinoma)
TFTs
Visual field testing
Assessment of pituitary function
How is a prolactinoma managed first-line?
Dopamine agonists: cabergoline, bromocriptine, quinagolide
Usually sufficient to shrink tumour (may need several years)
What are the causes of cranial DI?
Idiopathic Tumours Intracranial surgery Head injury Granulomata Cerebral infections Vascular disorders Post-radiotherapy Inherited
What are the causes of nephrogenic DI?
Idiopathic Hypokalaemia Hypercalcaemia CKD Drugs, eg lithium Renal tubular acidosis Pregnancy Post-obstructive uropathy Inherited
Why may DI cause incontinence in those able to get to the toilet?
Chronic overdistension of bladder
How may the signs in a pt with DI?
Signs of dehydration
Bladder may be enlarged and palpable
What investigations should you carry out in a patient with suspected DI?
24-hour urine collection Urine specific gravity Simultaneous plasma and urine osmolality U&Es Plasma glucose Serum calcium
Fluid deprivation test with response to desmopressin
Interpreting causes of DI on basis of water deprivation and desmopressin:
Urine Osmolality:
Before: low - After: high
Before: low - After: low
Before: high - After: high
- Cranial DI
- Nephrogenic DI
- Primary/ psychogenic polydipsia
What is the Mx of cranial DI?
Desmopressin (monitor for hyponatraemia, have tablet-free days)
What is the Mx of nephrogenic DI?
None just allow good access to fluids and correct metabolic abnormalities, drugs etc.
When may serum osmolality be normal (or increased) and urine osmolality be increased?
Dehydration, renal disease, congestive heart failure, Addison’s, hypercalcaemia, hyperglycaemia, hypernatraemia, alcohol ingestion, mannitol therapy
When may serum osmolality be normal (or increased) and urine osmolality be decreased?
DI
When may serum osmolality be decreased and urine osmolality be increased?
SIADH
When may serum osmolality be decreased and urine osmolality be decreased?
Overhydration, hyponatraemia, adrenocortical insufficiency
What are the causes of acromegaly?
Pituitary adenoma
Rare:
Ectopic GH from tumour
Inherited
Why are those affected with acromegaly susceptible to vertebral fractures?
Low-quality bone despite high bone mass
Why is acromegaly not tested with random GH?
Secretion is episodic and half-life is short
Which cancers are screened for in acromegaly?
Colon
Thyroid
What are the investigations for suspected acromegaly?
IGF-1
Assessment of other pituitary hormones as indicated: prolactin, adrenal, thyroid, gonadal
Blood glucose
Bone profile
Serum triglycerides
Visual tests
OGTT to confirm a raised IGF-1
ECG + echo
What is first-line management of acromegaly?
Trans-sphenoidal surgery (i.e. adenoma)
Otherwise, somatostatin analogues, eg octreotide
What are the causes of pseudo-acromegaly?
Insulin resistance associated with hyperinsulinaemia
What is the name for symptomatic hyperthyroidsm?
Thyrotoxicosis
What are the causes of hyperthyroidism? (7)
Graves Overgrowth of gland Tumour Subacute thyroiditis (de Quervain's) Ectopic thyroid tissue Over-treatment of hypothyroidism Drugs: amiodarone, thyroxine OD
What Ix would you carry out following TFTs?
Autoantibody screen
?Radioisotope scan (show ‘hot’ areas)
ECG if hyper (sinus tachy, AF)
What are the management options for hyperthyroidism?
Carbimazole (1 month for effect, sometimes block-and-replace)
Beta-blockers (palpitations, anxiety)
Radioiodine (slow uptake, may still need carbimazole)
Partial thyroidectomy
What blood finding in Graves?
Autoantibodies against TSH receptors
Graves eye disease:
- What are the findings?
- What is the cause?
- Management
- Exophthalmos, conjunctival oedema, lid lag, proptosis, weakening of extraocular muscles, keratitis (if trouble closing)
- Inflammation causes lymphocyte infiltration + activation of fibroblasts secreting osmotically-active hyaluronic acid
- STOP SMOKING, prednisoolone, lubricants
What is the name for symptomatic hypothyroidism?
Myxoedema
What are the causes of hypothyroidism? (7)
Hashimoto’s
Over-treatment of hyperthyroidism
De Quervain’s
Primary atrophic hypothyroidism
Dyshormogenesis (inherited defect, goitre)
Iodine deficiency
Drugs: lithium, amiodarone, excess iodine
How is hypothyroidism treated?
Levothyroxine
In emergencies, what medication is given to rectify hypothyroidism?
liothyronine (T3)
What are the ADRs of thyroxine?
Hyperthyroidism symptoms
What are the ADRs of carbimazole?
Hypothyroidism symptoms
In hypopituitarism, what must be corrected first?
Corticosteroids first to avoid Addisonian crisis
Which medications reduce absorption of thyroxine?
Calcium, iron replacements, antacids
What is the common sequence of symptomology experienced in Hashimoto’s?
Hyper –> eu –> hypo
De Quervain’s
- Definition
- Epidemiology
- Symptoms
- Pathology
- Prognosis
- Inflammation of gland by virus
- Young, middle-age women
- Tender, swollen + febrile illness
- Inflammation causes destruction of follicles, then immune reaction causes granulomas to form
- Usually left with hypo symptoms until gland recovers (days/ months)
Who is commonly affected by primary atrophic hypothyroidism?
Elderly - there is atrophy and fibrosis of gland.
Thought to be end-stage of many thyroid diseases
Causes of goitres
Physiological: puberty, pregnancy
Hyper: Graves’ (bruits, v vascular), thyroiditis
Hypo: all
Multi-nodular goitre (‘toxic’ if these produce hormones)
What might precipitate a thyroid emergency?
Surgery, radioiodine, infection, MI, stroke
What are the symptoms of thyrotoxic crisis (thyroid storm)?
Pyrexia, confusion, D+V, life-threatening arrhythmias, coma
What are the symptoms of a myxoedema coma?
Hypothermia, hyporeflexia, hypoglycaemia, bradycardia, seizures, coma
What TFTs would tell they require steroid therapy prior to thyroxine?
Secondary hypothyroidism (ie pituitary):
TSH LOW
T4 LOW
What TFTs may suggest subclinical hypothyroidism or poor compliance with thyroxine?
TSH High
T4 NORMAL
What do TFTs show in sick euthyroid syndrome (non-thyroidal illness)?
TSH Low (or normal) T4 Low (and esp T3)
How can steroid therapy affect TFTs?
TSH: low
T4: normal
What % thyroid lumps are benign?
How should they be investigated?
80%
TFTs + fine-needle aspiration
What is the mnemonic for thyroid cancers?
People forget medicine and mumble
Papillary Follicular Medullary Anaplastic Malignant lymphoma
Which thyroid cancer is associated with ectopic hormone production?
Medullary: arise in para-follicular cells
Calcitonin (usually asymptomatic)
ACTH (Cushing’s)
5-HT (Carcinoid syndrome)
Describe the histology of the adrenal gland
GFR+ MEGA
G- mineralocorticoids
F- glucocorticoids
R- androgens
medulla: 20% NA-secreting / 80% adrenaline-secreting
Mineralocorticoids: Example What are they stimulated by? (Which isn't v significant) Where does it act? What does it do?
Aldosterone
Hyperkalaemia, ACE II and ACTH (not so much)
Acts on DCT/CD
Increases water + salt retention, excretes K+
Glucocorticoids:
Example
Function
How does it exert circadian rhythm?
Cortisol
Regulates metabolism of carbs + proteins, maintains glucose levels when fasting / potent anti-inflammatory + immmunosuppressant
At 6am, exerts weaker neg feedback on CRH –> ACTH
Where are androgens from medulla converted to more active ones - under what enzyme?
In peripheral tissues, aromatase
When does the cortex start secreting androgens?
Andrenarche: 7-9 years
What are the signs of hyperaldosteranism?
Water + salt retention > hypertension [but not hypernatraemia due to other mechanisms] Polyuria + polydipsia Hypokalaemia Alkalosis Muscle weakness + spasm
What are the investigations of hyperaldosteronism?
U&Es
aldosterone
renin levels: decreased in primary, increased in secondary (eg in response to renal or heart failure)
ECG
Will need to be off certain meds
What is Conn’s syndrome?
A cause of secondary hypertension and hyperaldosteronism, caused by adenoma of zona glomerulosa
What are the causes of Cushing’s syndrome? (3)
Overtreatment with glucocorticoids
Ectopic ACTH production (eg oat-cell carcinomma)
Carcinoma of adrenal cortex
(Latter two: death may occur before development of cushingoid features)
What is Cushing’s disease?
Pituitary adenoa causing bilateral enlargement of cortex
Same symptoms + pigmented skin
Causes of pseudo-cushings
Depression, obesity, alcoholism
First-line investigation for Cushing’s syndrome
24-hour urinary free cortisol (represents 1%) - ideally 3 collections
In whom should suspicions of Addison’s be considered?
Hx of craving for salty food, postural hypotension, pigmented skin
Addisonian crisis
Unexplained recurrent hypoglycaemia
Hypothyroidism that gets worse despite thyroxine
Other auto-immune disease
What investigations should be carried out for adrenal insufficiency?
NB may be normal - no reserve when stressed
FBC U&Es Calcium Glucose LFTs Cortisol (between 8am-9am when highest)
Followed by:
ACTH
Renin:aldosterone (renin usually high, aldosterone low)
Synacthen test
What would be done during Addison’s ongoing monitoring?
Hx
Examination
Ix
Questions about symptoms, eg energy + appetite - questions about other auto-immune diseases (thyroid, diabetes, pernicious anaemia, coeliac)
Weight, BP (sitting + standing), examination of skin for pigmentation
U&Es, bone profile, TFTs, glucose + HbA1c, FBC, B12
What should be in an emergency Addison kit?
What are the sick days rules?
Hydrocortisone self-injection
Double the hydrocortisone
What are the typical biochem findings in Addison’s?
hyponatraemia, hyperkalaemia, hypoglycaemia, tendency for hypercalcaemia
What are causes of acute adrenocortical failure?
How does it present?
Bilateral haemorrhagic necrosis (sepsis/ DIC/ Waterhouse-Friderichson syndrome [meningococcal])
Stopping steroids suddenly (steroids stop ACTH production - so no endogenous cortisol for weeks)
How are phaechromocytomas treated?
Alpha-blockers for ~10 days, then surgery
Tumours where can produce same symptoms of phaechromocytomas?
Sympathetic ganglion (usually beside aortic bifurcation)
Order steroids in terms of mineralocorticoid content…
Fludrocortisone
Hydrocortisone (think water)
Prednisolone
Dexamethasone, betmethasone
What are the side-effects of steroids?
Glucocorticoids (Cushing’s)
Mineralocorticoids (like hyperaldosteronism) - be wary of prescribing alongside other meds that cause hypokalaemia
What should you consider prescribing alongside steroids?
Steroid-sparing agent, eg azathioprine, methotrexate
Bisphosphonates
PPIs
Causes of hyperglycaemia
DM
Glucagonoma
Causes of hypoglycaemia
Anti-diabetic meds/ poor control Alcohol Pituitary insufficiency (reduced GH) Insulinoma/ ectopic insulin Drugs: quinine, salicylates, propanolol
What is MODY?
Maturity-onset Diabetes of the Young
inherited, young patients, often not obese, at risk of DKA
What is LADA?
Latent Autoimmune Diabetes of Adults
often misdiagnosed as T2DM
If a patient is symptomatic for DM, how can this be diagnosed?
Fasting: 7+
Random: 11.1+
HbA1C: 6.5% (48 mmol) - but normal does not rule out
How is an asymptomatic pt diagnosed with DM?
Two readings
How is pre-diabetes diagnosed?
Fasting: 6.1 - 6.9
HbA1C: 42-47
When should HbA1C not be used?
When RBC life is prolonged (eg asplenic), or when RBC life is shortened (eg SCD)
Children + gestational
What medication is first-line for hypertension in DM?
ACEi (renoprotective)
If black, ACEi + thiazide/CCB
How is HHS differentiated from DKA?
Ketonuria ++ in DKA
What are the findings in DKA?
Dehydrated (glucose + ketones form diuresis)
Metabolic acidosis (ketones)
Hypokalaemia
What are the complications of DKA?
Cerebral oedema in kids
Cardiac dysarrhythmias
What are the causes of secondary diabetes?
Pancreatic disease: cystic fibrosis, chronic pancreatitis, pancreatectomy, ca pancreas
Endocrine: Cushing’s, acromegaly, thyrotoxicosis, phaechromocytoma, glucagonoma
Drugs: CS, among others
Hereditary: Friedrich’s ataxia, haemachromatosis
What is ideal BP if DM?
135/85
unless signs of end-stage organ damage: 130/80
When should short-acting insulin be injected?
15-30 mins before meal
How often should BM be checked if on insulin?
4 times/day (before each meal and before bed)
every 4 hours if ill
What level of hypoglycaemia should be treated in hospitals?
Below 4
Less-obvious way for hypoglycaemia to present?
Cardiac event
How often should HbA1c be checked in T2DM?
3-6 monthly until stabilised
6 monthly thereafter
What is HbA1c target in T2DM?
48 mmol (6.5%) if on mono-therapy 7.0% if on drugs associated with hypoglycaemia
Consider relaxing on case-by-case basis
Symptoms and management of gastroparesis
Gastrc bloating and vomiting
Domperidone
Side-effects of metformin
Lactic acidosis
GI disturbance
Step-up gradually
Mechanism of metformin
Increase insulin sensitivity
Decrease hepatic gluconeogenesis
Mechanism of sulfonylureas
Stimulate pancreatic beta cells
Side-effects of sulfonylureas
Hypoglycaemia
Hyponatraemia
Examples of sulfonylureas
Gliclazide
Glimepiride
What are the sick day rules for diabetics?
Keep a sick day pack with sugary food and fluids
Keep eating + drinking
Continue taking meds (inc insulin)
If T1DM: ketone sticks, 4-hourly BMs
If unable to eat and drink properly, seek medical advice
Normal serum calcium level
2.1 to 2.6
Symptoms + signs of hypocalcaemia
Paraesthesia Muscle cramps Carpopedal spasm Chvostek's sign Trousseau's sign
Seizures
Prolonged QT (leading to VF, heart block)
Laryngospasm
Bronchospasm
Causes of hypocalcemia
If low PTH: parathyroid agenesis (eg DiGeorge's syndrome) parathyroid destruction (surgery, radiotherapy, infiltrative disease) autoimmune disease
If high PTH:
vit D deficiency
hypomagnesaemia
pseudohypoparathyroidsm (PTH resistance)
Other: hyperventilation drugs (eg bisphosphonates) acute pancreatitis acute rhabdomyolysis malignancy
How to investigate hypocalcaemia?
Check: ideally take fasting blood sample fro uncuffed arm, ensure using adjusted calcium
U&Es (exclude CKD) amylase (exclude acute pancreatitis) creatinine kinase (exclude rhabdo) Phosphate Mg Vit D
ECG
How do you treat acute symptomatic hypocalcaemia?
Give 10 mL of calcium gluconate 10% by slow IV injection
Repeat if necessary (up to 40 mL/24h)
(Correct hypomagnesaemia first)
Which hypocalcaemics are prescribed calcitriol?
Renal impairment: doesn’t require hydroxylation by kidney
What are the symptoms of hypercalcaemia?
Mild: polyuria, polydipsia, dyspepsia, depression, mild cognitive impairment
Moderate: also muscle weakness, constipation, anorexia, nausea, fatigue
Severe: abdo pain, vomiting, dehydration, shortened QT interval, pancreatitis, coma
If long-standing, calcium deposited in soft tissues + stones
What are the causes of hypercalcaemia?
PTH-mediated
Malignancy
Granulomatous conditions
Others
What investigations for hypercalcaemia?
PTH
U&Es
Serum phosphate
ALP
(Consider urine calcium + phosphate)
When are PTH levels low in hypercalcaemia?
Granulomatous disease, renal dialysis, adrenal insufficiency, thyrotoxicosis
How should acute hypercalcaemia be administered?
IV fluids
After rehydration, bisphosphonates IV
Sometimes steroids or other drugs, depending on cause
Does vit D (calcitriol) increase or decrease serum calcium?
Increases absorption from gut
Causes of primary hyperparathyroidism
PT adenoma (80%), hyperplasia (20%)
Causes of secondary hyperparathyroidism
chronic renal disease
vit D deficiency/ malabsorption
ie IN RESPONSE TO LOW CALCIUM
When may osteitis fibrosa cystica result?
Secondary hyperparathyroidism
How is secondary hyperparathyroidism managed?
Diet modification/ phosphate binders
Vit D analogues
What is tertiary hyperparathyroidism?
If secondary hyperparathyroidism persists, level of calcium needed resets/ autonomous secretion of PTH
What are the lab findings in the three types of hyperparathyroidism?
PTH increased always
1: increased calcium, decreased phosphate
2: normal/ decreased calcium, increased phosphate
3: normal/ increased calcium, normal or decreased phosphate, normal or decreased vit D, increased ALP
What produces calcitonin?
C cells of thyroid
What investigations for hyponatraemia?
U&Es Glucose Lipids TFTs LFTs Plasma osmolality
Urine osmolality
Urine Na + K
What are the causes of hypernatraemia?
Pure free water loss, eg poor intake, DI
Hypotonc fluid loss, eg excessive sweating, burns, GI losses, urinary losses (eg diuresis)
Hypertonic sodiu gain, eg iatrogenic
What investigations for hypernatraemia?
U&Es
Calcium
Plasma glucose
Lithium levels, where appropriate (reduces lithium elimination)
If DI suspected: urine and serum osmolality
What is management of hypernatraemia?
Address underlying cause, withhold diuretics, lactulose
Seek specialist help so not to correct too rapidly (esp if chronic)
There are formulae to calculate amount of free water needed
What are the main causes of hypokalaemia?
Diuretics
GI lossses
What investigations for hypokalaemia?
Check with ABG
ECG: flat t waves, ST depression, prominent U waves
U&Es (concurrent low sodium suggests thiazides or marked volume depletion) Serum bicarbonate Serum glucose Serum chloride Serum magnesium
Urine: osmolality (needed to interpret urine K) urinary potassium (high = renal loss) urinary sodium (if low, and urinary K high = secondary hyperaldosteronism)
How to manage hypokalaemia?
Usually diet/ oral supplements
Administer KCl
Monitor 1-3 hourly
What investigations for hyperkalaemia?
Check: ABG
FBC
U&Es
Capillary + plasma blood glucose
24h urinary volume and electrolytes
If takes digoxin, check levels
What are the ECG changes in hyperkalaemia?
Tented t waves
Prolongation of PR interval
Widening of QRS
Other shit
If already has heart disease, bradycardia may be only new thing
How to manage hyperkalaemia?
If above 7 or ECG changes:
Stop medications that conserve potassium
Consider stopping digoxin and beta-blockers
10 mL 10% calcium gluconate (protect cardiac membrane) - up to 50 mL until ECG stabilises
Effects only last 30-60 mins
Insulin-glucose infusion (usually 10 units/25 g glucose) by IV: check BM before, during + after
Also give 10-20 mg nebulised salbutamol
Are other things to try, haemodialysis if necessary
MEN I
3 Ps
Parathyroid
Pituitary
Pancreas (insulinoma/ Zollinger-Ellinson)
MEN IIa
2 Ps
Medullary thyroid cancer
Parathyroid
Phaechromocytoma (bilateral)
MEN IIb
1 P
Medullary thyroid cancer
Phaechromocytoma
(Marfanoid body, neuromas)
PLACEHOLDER
Diabetes Meds
Endo causes of clubbing
Thyroid acropachy
Main steps in medical management of T2DM
Diet alone/ metformin: 48 mmol (6.5%)
Meds that might cause hypo, eg sulphonylurea: 53 mmol (7%)
If rises to 58 mmol (7.5%) - intensify treatment - add insulin (+metformin, +sulphonylurea)
Pregnancy and hyperthyroidism precaution
Carbimazole and methimazole are teratogenic
Propylthiouracil used instead
Thyroid and periods
Hyper: amenorrhea
Hypo: menorrhagia
What produces a woody hard thyroid?
Riedel thyroiditis
typically euthyroid but can be hypothyroid due to autoimmune fibrosis
can cause compression of local structures
treat with pred
which common med reduces hypoglycaemic awareness
beta-blockers