Adrenal and pituitary disease Flashcards
What is Addisons? Causes of primary, secondary, tertiary ai
It is a type of primary AI. It is where adrenal does not produce enough steroids (cortisol + aldosterone)
Causes
- Primary AI: Tb, AI, trauma, neoplasm, sarcoidosis, amyloidosis
- Secondary + Tertiary AI due to inadequate ACTH + CRH: pituitary/hypothalmus pathology, exogenous steroids >3w
Presentation of Addisons?
LEAN TANNED TIRED TEARFUL
(1. ) Lethargy
(2. ) Weakness
(3. ) Anorexia
(4. ) Wt loss
(5. ) Salt craving
(6. ) Postural hypotension
(7. ) Hyperpigmentation
Ix of Addisons
(1. ) Lying + standing BP: postural hypotension
(2. ) Bloods: UE (hyponatremia, hyperkalaemia), BGL (lo), 9am Cortisol (lo), ACTH (hi = primary, lo = secondary)
(3. ) Short Synacthen test (DX)
- Synacthen = synthetic ACTH
- Serum cortisol measured before + 30mins after administration
- Synthetic ACTH stimulates cortisol production and levels should double. Failure of cortisol to rise (less than double) indicates primary AI
Further Ix to establish cause
(1. ) Adrenal autoantibodies: present in 80% of autoimmune AI
(2. ) CT/MRI adrenals – if tumor
(3. ) MRI pituitary
Mx of Addisons
(1. ) Lifelong glucocorticoid and mineralocorticoid replacement (hydrocortisone + fludrocortisone)
(2. ) Androgen replacement (DHEA)
(3. ) Education pt, family/carers
(4. ) Carry steroid card
(5. ) Sick day rule
- Double dose if unwell with fever or flu-like illness or if in doubt
- IM 100mg hydrocortisone + 999 if vomiting or increasingly unwell
What is an adrenal crisis and how is it managed?
Life-threatening acute presentation due to absence of steroid hormones.
Triggered by infection, trauma, surgery, sudden steroid withdrawal
Presentation
- Hypovolemic Shock: raised HR, hypotension, oliguria
- Reduced consciousness
- Hypoglycaemia, hyponatraemia, hyperkalaemia
- Acute abdo pain
- N+V
Mx
- IM/IV 100mg hydrocortisone
- IV fluid
- Monitor electrolytes + fluid balance
- Glucose if hypoglycaemia
- Abx if infection
- Ix: ACTH, UE, BMs, cultures
What is Cushing syndrome and disease? Causes?
- Elevated glucocorticoid levels
- Cushing’s Disease = pituitary adenoma secretes excessive ACTH.
Causes
- ACTH dependent disease = pituitary tumour, ectopic ACTH producing tumour (small cell ca)
- non-ACTH dependent = adrenal adenoma, adrenal carcinoma
- Exogenous steroids
Presentation of Cushing syndrome
- Round moon face
- Central obesity
- Abdominal striae
- Buffalo hump
- Proximal limb muscle wasting
- Easily bruising and poor skin healing
- Gonadal dysfunction: irregular menses, hirsutism, erectile dysfunction
Signs of complications
- HTN
- Cardiac hypertrophy
- Hyperglycaemia + T2DM
- Depression
- Insomnia
- Osteoporosis
Ix for Cushing
Identify Cortisol excess
(1. ) Low dose dex suppression test (1st line)
- dexa suppresses ACTH
- Cushing syndrome = morning cortisol is NOT suppressed.
(2. ) 24hr urinary free cortisol
Localisation
(3. ) Hi dose dexa suppression test
- adrenal disease = hi cortisol
- pituitary disease = suppressed cortisol
- ectopic ACTH = hi cortisol, hi ACTH
(4. ) MRI – pituitary adenoma
(5. ) CT – chest for small cell lung ca or abdo for adrenal tumours
Mx of Cushing
Refer to end when suspected
- Stop medication, if possible, wean off steroids
- Surgery: Transsphenoidal removal of pituitary adenoma
- Surgery: Removal of adrenal / ectopic tumour
Acromegaly - what is it? causes?
- Acromegaly occurs when excess GH occurs after puberty.
- If before puberty, excess GH results in gigantism as long bones have not stopped growing at this point (no epiphyseal fusion).
- RF = Fx, Multiple endocrine neoplasia type 1 (MEN-1)
Causes:
- Pituitary benign adenoma (most common)
- Hypothalamic tumours
- Ectopic GH producing tumours
- Wermer’s Syndrome (MEN1)
Signs and Syx of acromegaly
Due to pituitary tumour:
- Headache, Bitemporal hemianopia
GH syx:
- Protrusion of forehead and jaw
- Enlargement of hand and feet: ask if they’ve had to change ring and shoe size
- Coarse facial features
- Macroglossia
- Excessive sweating and oily skin
- Joints ache and pain
- Dental changes: separation, jaw malocclusion, lower dental protruding, large tongue
Hypogonadal syx:
- Erectile dysfunction, dec libido, depressed mood
Signs of complications:
- Carpal tunnel syndrome
- DM
- CHF
- HTN
- OSA
- Anxiety + depression
Ix of acromegaly
(1.) Serum IGF1 (1st line test) if suspect acromegaly.
(2. ) 75 gm OGTT (confirms Dx)
- If IGF1 is raised proceed to OGTT.
- GH is normally inhibited by glucose. In acromegaly there is no suppression.
- If the glucose load fails to suppress GH below 1.0 mcg/L this confirms dx
(3. ) MRI - if acromegaly is confirmed, assess for tumour.
(4. ) ECG - Cardiac changes such as hypertrophy
Mx of acromegaly
(1.) 1st line: Transsphenoidal Surgery (for pituitary adenoma)
(2. ) if surgery not possible:
- DA agonist (Carbergoline)
- Somatostatin analogues
- GH receptor antagonist
- Pegvisomant
What is DI? Causes? Syx?
- Lack or no response to ADH which allowed for water renal reabsorption
Causes
- Nephrogenic (Kidney does not respond to ADH): lithium, AVPR2 mutation, kidney disease, hypokalaemia, hypercalcaemia
- Cranial (Hypothalamus does not produce ADH): idiopathic, brain tumour, head injury, brain malformation, infection, surgery, radiotherapy
Presentation
Polyuria, Polydipsia, Dehydration, Postural hypotension
Ix for DI
(1. ) UE + osmolarity: hi serum osmolarity, hypernatremia
(2. ) Low urine osmolarity
(3.) Water deprivation + desmopressin stimulation test Dx*
- Cranial DI:
• After deprivation = low urine osm
• After desmopressin = hi urine osm
- Nephrogenic DI (unable to respond to ADH)
• After deprivation = low urine osm
• After desmopressin = low urine osm - Primary polydipsia
• After deprivation = hi urine osm
• After desmopressin = hi urine osm
