Endocrine Flashcards
A CT head shows bleeding on the pituitary gland, what is this and what is the most common cause?
- Pituitary apoplexy is heamorrage of pituitary gland
- Often caused by tumour (macro adenoma)
What investigations should you do for pituitary apoplexy, IN THE ORDER OF MOST IMPORTANT?
What would you expect to see?
1) CT head-bright white in middle by pituitary gland
2) pituitary hormones
- cortisol>CHECK ASAP-if low give hydrocortisone
- thyroid
- sex hormones
- growth hormones
3) visual field problems (bilateral hemianopia a.k.a tunnel vision) caused by compression of the optic chiasma
If hypercalcemia is parathyroid dependant what would you expect to see?
- raised PTH
- high Calcium, low Phosphorus
treatment for thyroid storm?
Thyroid storm
1) Propylthiouracil
2) Hydrocortisol (prevent peripheral conversion of T3 and T4)
3) Symptom control
- Beta blocker
- IV fluids
**monitor heart for arrhythmias
Explain the negative feedback loop of the hypothalamus, anterior pituitary gland and the adrenal glands
Negative feedback loop
1. Hypothalamus produces cortico-trophic releasing hormone CRH
- This causes Anterior pituitary gland to release ACTH (adreno-cortico-trophic hormone)
- ACTH causes the adrenal cortex to release
a) mineralocorticoids(aldosterone)
b) glucocorticoids (cortisol)
c) androgens
What are the effects of the 3 hormones secreted by the adrenal gland?
Adrenal gland hormone
- Mineralocorticoids (aldosterone)
- Na+ and water retention>↑BP - Glucocorticoids (cortisol)
- immunosuppressant and anti inflammatory
- skin thinning
- metabolism (weight gain and insulin resistance
- bone effects (↑osteoclasts>osteopenia and osteoporosis) - Androgens
- more effect for females
Presentation of adrenal insufficiency?
ADRENAL INSUFFICIENCY PRESENTATION
- fatigue, depression, ↓self-esteem, psychosis
- tan/pigmentation (skin/buccal mucosa/palmar creases)
- anorexia and weight loss (can be mistaken for anorexia)
- signs of dehydration
- dizzyness/syncope
- nausea, vomiting (↓Na+)
- abdo pain, constipation or diarrhoea
- arthralgia/myalgia
- decreased libido
- low grade fever
- loss of hair
- can present ACUTELY with circulatory collapse
Investigations and findings of adrenal insufficiency? (bedside, bloods, imaging,special)
Bedside
- low BP and signs of dehydration
- ECG (tachy to compensate for low BP)
Bloods
- Us+Es (HYPONATREMIA, HYPERKALEMIA)
- 9am serum cortisol QUICKEST TEST (reduced)
- Glucose (hypoglyceamic-due to ↓cortisol)
- ABG (metabolic acidosis due to↓aldosterone> ↓HCO3- )
Imaging
-Could do if concerned primary malignancy, mets or infection (TB-CXR)
Special test
- SynACTHen test (diagnostic ∆ ) <420nmol/L cortisol suggests primary adrenal deff -however takes longer so would prob just treat before results
- Adrenal antibodies (21 hydroxylase Ab + ve 80% in Addisons). If negative consider TB
Long term management for Adrenal insufficiency?
ADRENAL INSUFFICIENCY MANAGMENT
- Mineralocorticoid replacement: fludrocortisone (only in primary because RASS has less effect)
- Glucocorticoid replacement: daily hydrocortisone (divided doses throughout day-mimic normal fluctuations)
- Androgen replacement: DHEA (Dehydroepiandrosterone is produced by adrenals whereas testes produce androgens)
What are the clinical effects of
↓Mineralocorticoids
↓ Glucocorticoids
↓Androgens
↓Mineralocorticoids (aldosterone)
- Hyperkaleamia ↑K+
- Hyponatreamia (↓Na+and ↓water retention)>↓BP> compensatory ↑HR
- Metabolic Acidosis (aldosterone reabsorbs bicarb(↓HCO3-)
↓Glucocorticoids
- weight loss
- fatigue
- ↓gluconeogenesis ↓blood glucose
↓Androgens (more effect on women)
- ↓libido
- ↓Pubic hair
-skin pigmentation our to compensatory hyper-pituitary activity → ↑melanocyte stimulating hormone
Causes of adrenal insufficiency
Causes of adrenal insufficiency
- ADDISONS DISEASE (autoantibodies against adrenal cortex +/- hydroxylase autoimmunity)
- infection
- malignancy or mets
- infiltration diseases (heamochromatosis or amyloidosis)
- adrenal heamorrage (warfarin) or infarction
- iatrogenic (Surgery)
- congenital adrenal hyperplasia
What are the cut-offs for cortisol test?
What does high ACTH mean? What does low/norm ACTH mean?
9am ↓Cortisol and ACTH
-allows differentiation of 1 vs 2
Cortisol < 100 (Addison’s likely admit to hospital )
100-500 (do Synacthen test);
> 500 (unlikely Addison’s)
↑ACTH = primary (pituitary trying to compensate);
↓ or norm ACTH = secondary (↓pituit. sec is the issue)
What things might interfere with cortisol test?
What would you do to overcome this?
- shift workers
- patients on long term steroids
- patients on oestrogen therapy
- do ACTH test instead
How does the ACTH stimulation test work?
-Synacthen® ACTH stimulation test is diagnostic ∆
- First, measure plasma cortisol
- Then, give IM Synacthen (tetracosactide), wait 30 min
- Then, measure plasma cortisol
- If 30 min cortisol < 500 nmol/L = Addison’s
- If 30 min cortisol > 550 nmol/L = not Addison’s
Refer to endocrinologist
What advice can you give to someone taking steroids for adrenal insufficiency?
STEROIDS ADVICE-ADRENAL INSUFFICIENCY
- Warn not to abruptly stop steroids (risk of crisis)
- DOUBLE hydrocortisone dose alone in febrile illness
- provide IM hydrocortisone if vomiting prevents oral intake
- give blue steroid card
Symptoms of addisonian crisis?
Addisonian crisis
- dehydration>hypotension>HYPOVOLEAMIC SHOCK>altered consciousness>death
- seizures
- stroke or cardiac arrest
What is the ACUTE management for Adrenal insufficiency?
ACUTE adrenal insufficiency
1) Sugar (dextrose)
2) Steroids (IM or IV)
2) Saline
3) Search for cause
What is Waterhouse-Friderichsen syndrome
- complication of sepsis (particularly meningococcal sepsis)
- hemorrhagic necrosis of the adrenal glands
- cause adrenal crisis
Explain how parathyroid hormone works?
- low levels of calcium detected in blood
- causes PTH gland to release PTH
- PTH causes:
a) ↑osteoclast activity and ↑calcium resorption from bone
b) Activates vitamine D so ↑Ca2+ absorption from gut
c) ↑Ca2+ reabsorption from kidneys
PTH also stimulates vitamin D production from kidneys
What is the most common cause of primary hyperparathyroidism
PRIMARY HYPERPARATHYROIDISM CAUSES
- Most common cause is Parathyroid adenoma (80%)
- Hyperplasia (20%)
- Parathyroid carcinoma (<0.5%)
What are risk factors for primary parathyroidism?
PRIMARY HYPERPARATHYROIDISM
- post menopausal women
- MEN1/2a
Symptoms of hyperparathyroidism? (nervous system, cardiac, GI, urinary, MSK)
PRIMARY HYPERPARATHYROIDISM (symptoms of high calcium- MOANS/BONES/ GROANS/ THRONES Nervous system -cognitive impairment -depression/fatigue -confusion>drowsy>siezures>coma
Cardiac
-Arrhythmias (do ECG)
GI system
- abdo pain
- N and V
- loss of appetite
- constipation
Urinary system
- kidney stones (most common)
- increased urination
- increased thirst
MSK
- bone pain
- muscle weakness
70-80% are asymptomatic and diagnosis is often incidental
What investigations would you do for hyperparathyroidism and what would they show? (bedside, bloods, imaging, special)
PRIMARY HYPERPARATHYROIDISM Bedside -Blood pressure (↑HTN)-PTH>aldosterone -ECG – may present with short QT interval -24hr Urinary Ca2+ (↑Ca2+)
Bloods (calcium should be corrected for albumin)
- U+Es (↑PTH / ↑Ca2+ / ↓PO4, check Mg (PPI causes low Mg and low Ca2+)
- LFTS - ↑ALP (bone resorption – osteopenia)
Imaging
-DEXA scan – determine level of osteoporosis/dystrophy (see complications)
Special- biopsy
-if ?carcinoma
What are the 2 options for hyperparathyroidism treatment?
PRIMARY HYPERPARATHYROIDISM
- Conservative if:
- kidneys working well with no stones
- only slightly elevated Ca2+
- bone density okay
- if surgery unsuccessful or unsuitable - Surgery
- high serum/urinary calcium
- osteoporosis
- ↓renal function/renal calculi
- age <50 years
What is the conservative management of primary hyperparathyroidism? (4)
Conservative treatment:
- ↑fluid intake and avoid thiazide diuretics
- Calcimimetics (Cinacalcet) -when surgery unsuitable/unsuccessful) ↑sensitivity of parathyroid cells to ca2+ levels → ↓PTH secretion
- Bisphosphonates if ↑fracture risk
- Replenish Vitamin.D (Cholecalciferol – non-active)
what is the surgical treatment for hyperparathyroidism?
What are the complications of surgical treatment?
SURGERY
-Parathyroidectomy
Complications
- hypothyroidism
- recurrent laryngeal nerve damage (hoarse voice)
- symptomatic ↓Ca2+ (check Ca2+ daily for ≥ 14 d post-op)
What type of lung cancer is associated with ↑PTH?
-Squamous cell carcinoma is associated with ↑PTH (also seen in breast and renal cancer)
What are two complications of primary Hyperparathyroidism (2)
Osteitis fibrosa cystica
- bones replaced by fibrous tissue
- salt and pepper skull
- brown tumours of long bones
- dissapearance of distal clavicle
Nephrocalcinosis-loads of calcium in kidneys
Define:
- primary Hyperparathyroidism
- secondary Hyperparathyroidism
- tertiary Hyperparathyroidism
Primary Hyperparathyroidism
-excess PTH independant of Ca2+ levels
Secondary Hyperparathyroidism
-excess PTH in response to chronic hypocalcaemia
Tertiary Hyperparathyroidism
- prolongued secondary hyperparathyroidism
- when secondary is treated, the PTH baseline is still increased → HYPERcalcaemia
What would the PTH/ calcium/vit D/phosphate/ALP be in primary/secondary/tertiary hyperparathyroisim?
osteomalacia?
Primary
↑PTH / ↑Ca2+ / ↑vitamine D / ↓phosphate/ ↑ALP
Secondary:
↑PTH /Ca2+↓ or normal /↓Vitamin D/ ↑phophate
Tertiary
↑↑PTH / ↑ Ca2+/ ↓Vitamin D/↓phosphate if CKD normal phosphate (if kidneys transplant)/ ↑ALP
Osteomalacia
↓Vit D ↓Ca ↓Ph ↑PTH ↑ALP
What is secondary hyperparathyroidism?
What is the most common causes?
SECONDARY HYPERPARATHYROIDISM
- excess PTH in response to chronic hypocalcaemia
- causes hyperplasia of PT gland to compensate for low calcium
Common causes:
- CKD (common)
- ↓Calcitrol (active vit.D)> ↓GI tract Ca2+ absorption> ↓free calcium ions
- Vitamine D defficiency (↓Calcitrol)
- lack of sunlight, poor vitamin D intake
-Bowel absorption problems/liver problems
What are the symptoms of secondary hyperparathyroidism?
SECONDARY HYPERPARATHYROIDISM
(symptoms of low calcium)
- Starts with confusion/tiredness
- Tetany – twitching, cramping, spasms
- Perioral paraesthesia
- Siezures
- Trousseau (BP cuff and cramp)
- Chvostek’s sign (tap parotid, causing facial twitch)
What is the treatment of secondary hyperparathyroidism?
SECONDARY HYPERPARATHYROIDISM
- Correct cause – treat CKD or Vitamin D def (Ergocalciferol-high dose. Colecalciferol for maintenance)
- Cinacalcet if PTH ≥ 85
What is tertiary hyperparathyroidism?
What is the treatment of tertiary hyperparathyroidism?
Tertiary hyperparathyroidism
-prolongued secondary >HYPERcalceamia
Treatment: surgery to remove hyperplasia glands and return PTH to baseline
What is the 2nd most common cause of hypercalceamia?
Cancer is 2nd most common cause of hyperparathyroidism (after primary HP)
What would the calcium/phosphate/PTH/phosphate/ALP be in hypercalcemia due to malignancy?
- ↑Ca2+ and ↓phosphate (↑Urine phosphate)
- normal or ↓ (compensation) PTH
- ↑Serum ALP
- low albumin
What would you see on ECG with HYPER calceamia?
ECG IN HYPERCALCEMIA Most common: Short Q/T interval -wide T-waves -BBB -prolonged PR interval -arrhythmia -J waves
Treatment of hypercalcemia of malignancy
HYPERCALCEMIA MALIGNANCY
Fluids → bisphosphonates
STEP 1: Fluids
- IV Fluids (rehydration)
- normal Saline 0.9% 3-4L/day (rate 250ml/hr) with adequate K+ (20 or 40mmols)
- administer with Furosemide if ↑risk of fluid overload (also promotes ↑Ca2+ excretion ☺)
STEP 2 IV BISPHOSPHONATES
- Zolindronic acid or Pamidronate (inhibit osteoclast bone resorption) if Ca2+ > 3
What are some causes of SECONDARY hyperlipidemia?
Secondary hyperlipidaemia
- Cushing’s synd
- Hypothyroidism
- Nephrotic syndrome
- Cholestasis (↓bile)
- Anorexia nervosa
- Alcohol
- Obesity
What are some signs of hyperlipidemia?
HYPERLIPIDEAMIA
- Premature corneal arcus – white grey opaque ring in corneal margin
- Tendon xanthomata – hard, non-tender nodular enlargement of tendons (knuckles and Achilles
- Xanthelasma – yellow plaques around eye
What bloods would you get in hyperlipideamia?
Hyperlipideamia (get full lipid profile)
- total cholesterol (refer to speilaist if >9)
- HDL-C
- non HDL-C
- Triglycerides
Phaeochromocytoma
Features?
Test?
Treatment?
Phaeochromocytoma (features are typically episodic)
- hypertension (around 90% of cases, may be sustained)
- headaches
- palpitations
- sweating
- anxiety
Tests
-24 hr urinary collection of METANEPHRINES
Treatment:
-Surgery is the definitive management.
-The patient must first however be stabilized with medical management:
alpha-blocker (e.g. phenoxybenzamine), given before a
beta-blocker (e.g. propranolol)
