Hypopituitarism Flashcards
What type of hypothyroidism is more common?
Primary
Describe T3, T4 and TSH levels in primary hypothyroidism
T3 and T4 fall
TSH increases
Describe T3, T4 and TSH levels in secondary hypothyroidism
T3, T4 and TSH fall
What is primary hypothyroidism?
Autoimmune destruction of the thyroid
Describe cortisol and ACTH levels in primary hypoadrenalism
Cortisol falls
ACTH increases
Describe cortisol and ACTH levels in secondary hypoadrenalism
ACTH and cortisol falls
Out of cortisol and aldosterone what is regulated by ACTH?
Only cortisol, aldosterone is regulated by renin angiotensin
Describe LH/FSH, testosterone/oestrogen levels in secondary hypogonadism
All fall
Describe LH/FSH, testosterone/oestrogen levels in primary hypogonadism
LH/FSH increase
Test/oest fall
What are the main causes of hypopituitarism?
Acquired eg tumor, radiation, infection, surgery, inflammation, brain injury
What is loss of anterior and posterior pituitary function called?
Panhypopituitarism
Which pituitary hormones are most sensitive to radiation?
GH and gonadotrophins
How does hypopituitarism present- go through all the hormones?
FSH/LH= Reduced libido, Secondary amenorrhoea, Erectile dysfunction, Reduced pubic hair
ACTH= fatigue
TSH= fatigue
GH= reduced quality of life
Prolactin= inability to breastfeed
What is Sheehan’s syndrome?
Post-partum hypopituitarism secondary to hypotension (post partum haemorrhage - PPH)- the enlarged pituitary gland doesnt get enough blood and infarcts
What happens to the anterior pituitary during pregnancy?
Enlarges
How does Sheehan’s syndrome present?
Lethargy, anorexia, weight loss – TSH/ACTH/(GH) deficiency
Failure of lactation – prolactin deficiency
Failure to resume menses post-delivery
Posterior pituitary usually not affected
How do you view the pituitary gland?
Pituitary MRI
What is pituitary apoplexy?
Intra-pituitary haemorrhage or infarction
How does pituitary apoplexy present?
Severe sudden headache
Bitemporal hemianopia
Diplopia or ptosis (droopy eyelid)
How is hypopituitarism diagnosed?
Induce hypoglycaemia (via insulin injection) so they release stress hormones (GH and ACTH) and measure cortisol
Inject TRH to stimulate TSH release and measure
Inject GnRH to stimulate FSH and LH release
How is hypopituitarism treated- go through all the hormones?
GH= GH replacements- then do a questionnaire to measure quality of life and measure plasma IGF-1
TSH= levothyroxine
ACTH= replace cortisol using prednisolone or hydrocortisone
FSH/LH= for men if no fertility needed replace testosterone, if needed gonadotropin injections. foe women if no fertility needed replace oestrogen if needed induce ovulation via gonadotropin injections (IVF)
What is the daily dose of prednisolone?
3mg once a day
What is the daily dose of hydrocortisone?
3 times a day 10/5mg
What are sick day rules for ACTH?
At risk of adrenal crisis if they miss a day of their meds so they:
should wear a steroid alert
double their steroid dose if fever
if unable to take meds eg vomitting go to A&E straight away
What happens to FSH/LH in menopause?
Levels rise
