General Endocrine Conditions Flashcards
Causes of hypercalcaemia
- Hyperparathyroidism - primary or tertiary (NOT secondary)
- Familial hypocalciuric hypercalcaemia
- Malignancy - multiple myeloma, humoral hypercalcaemia(PTHrP), bony mets
- Vitamin A or D intoxication
- CKD
- Sarcoidosis
- Hyperthyroidism
- Addisons
- Drugs eg Lithium/thiazides
- Immobilisation
What is familial hypocalciuric hypercalcaemia?
When body has problem of parathyroid detecting Ca2+ levels
What is tertiary hyperparathyroidism?
When you have had secondary hyperparathyoidism for a while and this then results in overactivity/solitary adenoma of pituitary gland
Clinical features of hypercalcaemia
- Bones - fragility fractures, bone pain
- Stones - renal calculi
- Thrones - polyuria, constipation
- Psychic moans - mood disturbance, fatigue/malaise
- Abdominal groans - abdo pain, pancreatitis
- Asymptomatic?
Complications of hypercalcaemia
- Renal calculi
- Osteoporosis
- Pancreatitis
Investigations for hypercalcaemia - steps
- Find raised Ca2+
- Check PTH
- If low - screen for cancer
- If high PTH - check urine Ca2+ creatinine clearance ratio
- If low urine Ca2+ –> FHH? Do genetic testing
- If high urine Ca2+ - suspect primary hyperparathyroidism
Other investigations for hypercalcaemia
- CXR
- FBC
- ACE - sarcoidosis
- TFTs
- Cortisol
- Vitamin D
- Myeloma screen
- Assess for end organ damage
Why do assess for end organ damage in hypercalcaemia and how?
US KUB, DEXA scan
If end organ damage - fill criteria for surgical management
Indications for surgery in primary hyperparathyroidism causing hypercalcaemia
- Very symptomatic
- End organ damage - worsening kidney function, renal stones
- Osteoporosis on DEXA
- Ca2+ more than 3
- Urine Ca2+ 10mmol/day
- Age under 50
Surgical management for primary hyperparathyroidism
- Surgical removal of adenoma or partial parathyroidectomy
Medical management for primary hyperparathyroidism
- Only indicated if not suitable for surgery (surgery 1st line)
- Cinacalcet - Ca2+ sensing agonist
- Bisphosphonates
- HRT
Medical management not first line as it will lower calcium but not affect urinary calcium
Emergency management for severe hypercalcaemia
- If renal failure - dialysis
- Aggressive IV hydration (if then overloaded use loop diuretics)
- Once volume replete consider bisphosphonates
- Calcitonin, steroids or denosumab rarely used
Causes of hypocalcaemia
- Hypoparathyroidism
- Iatrogenic - thyroid surgery
- Radiation
- Infiltration
- Autoimmune - but we don’t really do PT autoantibodies screen
- Familial/syndromic - DiGeorge, overactivity of Ca2+ sensing receptor
- Magnesium deficiency
- Drugs - PPI, Cisplatin, calcitonin, phosphate, citrate
- Pseudohypoparathyroidism
- Vit D deficiency/resistance
- CKD
- Osteoblastic mets (eg prostate Ca)
Symptoms of hypocalcaemia
- Tingling/numbness
- Cramps
- Neuropsychiatric
- Carpopedal spasm
- Seizures
Signs of hypocalcaemia
- Stridor
- Chvostek’s - tap facial nerve and face spasms
- Trousseau’s - inflate BP cuff and carpopedal spasm occurs
Syndromic vs iatrogenic hypocalcaemia
Iatrogenic hypocalcaemia behaves much more aggressively than familial/syndromic causes
Investigations for hypocalcaemia
- Serum Ca
- PTH
- Vitamin D
- Magnesium
Management of hypocalcaemia
- Calcium supplement - aim to keep calcium level just below normal range
- Vitamin D - alfacalcidol, calcitriol
- PTH not approved
Emergency management of acute hypocalcaemia
- IV calcium gluconate (20ml of 10% in 100-200ml saline) over 10 mins
- Calcium infusion (40ml of 10% calcium gluconate in 1L saline over 24hrs)
- Check Ca every 6 hours
- Replace Mg as needed
Severities of hyponatraemia
- Normal - 133-146mmol/L
- Mild - 127-132
- Moderate - 121-126
- Severe - 120 or less
Symptoms and signs of hyponatraemia
- Changes in personality - confusion/short temper
- Headache
- Fatigue
- Convulstions/seizures
- Feeling weak
- Loss of conc/coma
- Low BP
- Feeling nauseous/vomitting
Causes of hyponatraemia
- Hypervolaemic - CKD, CHF, liver cirrhosis, nephrotic syndrome
- Euvolaemia - medications (eg diuretics thiazides), glucocorticoid deficiency, severe hypothroidism, SIADH
- Hypovolaemia - renal or extra-renal loss of sodium
Investigating hyponatraemia
- Rule out artefactual cause - if blood sample taken from same arm as IV fluids
- Patient diabetic? - Hyperglycaemia can cause dilutional hyponatraemia
- Assess fluid status
- Review relevent clinical history - CHF, CKD, liver failure, lung pathology?
- Constituional symptoms - malignancy?
- Consider medications
Medications which can cause hypocalcaemia
- Thiazide diuretics
- Loop diuretics
- Potassium sparing diuretics
- Combined diuretics
- Angiotensin II receptor antagonists
- Tricyclic antidepressants
- SSRIs
- MAO inhibitors
- PPIs - omeprazole
- Anticonvulsants - carbamazepine, valproate
Investigations for hyponatraemia
- Serum and urine osmolality
- Urine Na+ and K+
- Plasma glucose
- 9am serum cortisol if suspect glucocortocoid deficiency
- Short synacthen test maybe
- TFTs
- Other investigatiojs depend on cause
Criteria for diagnosing SIADH
- Serum osmolality less than 275mosm/kg
- Urine osmolality more than 100mosm/kg
- Urine sodium more than 30mmol/L - if Na was low, suggests body holding onto Na+ and is hypovolaemic
- Absence of adrenal, thyroid, pituitary or renal insuffiency
- Clinically euvolaemic
Management of hypovolaemic hyponatraemia
- Rehydrate with 0.9% NaCl
- Check U&Es after infusion and prescribe further fluids if needed
Management of hypervolaemic hyponatraemia
- Fluid and salt restriction
- Consider diuretics
- Treat underlying cause
Careful with diuretics, they can sometimes worsen low Na
Treatment of euvolaemic hyponatraemia
- Treat the cause - chest infection, malignancy, hormonal insuffiency
- If SIADH - fluid restriction (750-1000mls per day)
- If serum Na not corrected despite fluid restriction consider Tolvaptan or Demeclocylcine
Emergency management of hyponatraemia
- Within 1st hour - IV infusion of 150ml 3% hypertonic saline or equivalent (over 20mins)
- Check Na - IV infusion of 150ml of 3% hypertonic saline
- Repeat twice or until 5mmol/L increase in Na
F/u management after 5mmol/L increase in Na in emergency hyponatraemia management
- Stop IV infusion of hypertonic saline
- Keep IV line open minimum volume of 0.9% saline
- Start diagnosis specific treatment
- Limit increase of Na+ to 10mmol/L within first 24hrs - risk of central pontine demyelination
- Limit increase Na+ to additional 8mmol/L every 24hrs therafter until Na+ 130mmol/L
- Check Na 6hrs, 12hrs, and daily until stable
Severity hyponatraemia
mild: 130-134 mmol/L
moderate: 120-129 mmol/L
severe: < 120 mmol/L
Two sources of hyperandrogenism in females
- Ovaries = PCOS, CAH
- Adrenals
- Others - acromegaly, idiopathic, cushings
- Androgen secreting tumour
How can Cushings cause hyperandrogenism?
Androgens in adrenal gland are under ACTH control
Red flags for androgen secreting tumour
- Rapid onset
- Virilisation
- Testosterone very high - more than 5nmol/L
Signs of virilisation
- Frontal balding
- Deepening of voice
- Increased muscle mass
- Clitromegaly
Steps for investigating hyperandrogenism
- Check testosterone
- Abdo USS
- If suspect PCOS - rule out Cushings with Dexamethasone suppression test
- If suspect Adrenal cause - can do ACTH suppression test
- If suspect ovarian cause, can give GnRH will should suppress
Criteria for diagnosing PCOS
Rotterdam criteria - need 2/3
* infrequent or no ovulation (usually manifested as infrequent or no menstruation)
* clinical and/or biochemical signs of hyperandrogenism (such as hirsutism, acne, or elevated levels of total or free testosterone)
* polycystic ovaries on ultrasound scan
Multiple endocrine neoplasia
- Autosomal dominant inheritance
- MEN 1, 2A and 2B
- Each type has particular cancers associated with it
MEN 1
- Pituitary adenoma
- Parathyroid hyperplasia
- Pancreatic tumours
3Ps
MEN 2A cancers
- Medullary thyroid cancers
- Parathyroid hyperplasia
- Phaechromocytoma
2Ps
MEN2B cancers
- Medullary thyroid carcinoma
- Phaechromocytoma
- Marfanoid
- Mucosal neuromas
1P
MEN 1 vs MEN2 genes
- MEN1 - MEN1 gene on chromosome 11
- MEN2 - C-RET oncogene on chromosome 10
Testing for medullary thyroid cancer
Calcitonin
