endocrine Flashcards
causes of hypoglycaemia
DM alcohol excess quinine, SSRI insulinoma hypothyroid hepatitis renal dyalysis
what level of blood sugar should you treat for hypo?
<4.0mmol/L
hypoglycaemic and unconscious
10g glucose 20% through large vein
hypoglycaemic and conscious
glucogel/ oral glucose 10g
name some factors that would prompt critical care review in DKA
ketones >6mmol/L SBP<90 K <3.5 GCS<12 pH<7
3 criteria for diagnosis of DKA
capillary BM >11/ known DM
capillary ketones 3+mmol/L
venous bicarb <15mmol/L and/or pH <7.3
what insulin regime should be used in DKA
fixed rate IV insulin infusion- not sliding scale as inaccurate in overweight/ pregnancy
first bag of fluid in DKA
0.9% NaCl 1L over 1 hour unless hypotensive (500ml bolus-> no response call senior)
baseline investigations in DKA
VBG hourly CXR ECG urine dip pregnancy test
what is the definition of resolution of DKA?
blood ketones <0.6 mmol/L and venous pH >7.3
what 2 things should you watch for when treating DKA?
hypoglyceamia
hypokalaemia
diagnostic criteria for DM
HbA1c >48
OR Fasting glucose > 7 mmol/L and a glucose tolerance test
OR random glucose > 11mmol/L (usually on 2 separate occasions)
Management
pathology of T1DM
T cell mediated destruction of B cells
what is an abnormal oral glucose tolerance test
give 75g anhydrous glucose, after 2 hours BM>11mmol/L
If DM and HTN what drug start on
ACEI regardless of age as also reduce risk of nephropathy and albuminurea
3 ways in which DM causes kidney damage
Glomerular damage
Ischemia caused by damage to efferent and afferent arterioles.
Ascending infection
what is often the first way in which diabetic nephropathy can be picked up?
albuminurea, note can cause episodes of nephrotic syndrome (hypoalbuminurea and oedema)
how might diabetic neuropathy present?
symmetrical mainly sensory neuropathy (stocking and glove)
acute painful neuropathy (often in shins)
mononeuropathy (carpal tunnel)
autonomic neuropathy (erectlie dysfunction, silent MI)
sulphonylurea (gliclazide)
hypo risk, low sodium, weight gain
DDP-4 inhibitor e.g. sitagliptin
risk of pancreatitis
at what eGFR is metformin contraindicated?
<30, 30-60 reduce dose
SGLT2 inhibitor e.g. empagliflozon
low hypo risk, lose weight, wee lots and UTI risk
side effects of metformin
epigastric pain, anorexia and diarrrhoea, avoid in severe liver/ kidney disease
complication of injecting insulin
lipohypertrophy of injection site, weight gain (makes you feel hungry)
insulin requirement
0.5-1 unit/kg/day
target BP for diabetics
<130/ 80
target cholesterol for diabetics
<4.5
2 most common causes of hyperthyroidism
graves
nodular thyroid disease
what is the pathology in Grave’s
TSH receptor stimulating antibodies
how is T3 released
hypothalamus releases thyrotropin releasing hormone->
anterior pituitary releases TSH->
thyroid releases T4, converted into T3 in liver/ kidneys
what eye changes can be seen in Grave’s? note eye changes only in Grave’s
exophthalmos
ophthalmoplegia
lid lag
name 2 other conditions that commonly occur with Grave’s
AI conditions: myasthenia gravis, pernicious anaemia
how does a thyrotoxic storm present?
history of acute illness marked fever >38.5 siezures N+v+ diarrhoea jaundice death- arrhythmias
subclinical hyperthyroidism
symptoms present
TSH normal/ low
T4/ T3 normal
what scan is used to differentiate different causes of hyperthyroidism?
radionuclide scan
what benefit do BBs have in Grave’s?
symptom control
reduce peripheral conversion of T4-> T3
What is the side effect of carbimazole to be aware of?
agranulocytosis, therefore sore throat etc come for FBC
what is the long term complication of hyperthyroidism?
osteoporosis
Toxic Multinodular Goitre
older female, high dietary iodine/ amiodarone
2 main causes of hypothyroidism
primary- autoimmune/ damage from radioiodine (also lithium, amiodarone, interferon)
iodine deficiency
subclinical hypothyroidism
TSH high
T3/T4 normal
no symptoms
Hashimoto’s pathology
T cells attack thyroid, causes firm and rubbery goitre (other causes of hypothyroid do not)
myxoedema
thickened, coarse skin in hypothyroidism
name 2 other conditions that commonly occur autoimmune hypothyroidism
addison’s
pernicious anaemia
pre-tibial myxedema
hyperthyroidism, big fatty looking growth.
what effect does PTH have on the kidneys?
increases Ca resorption and phosphate excretion
what effect does PTH have on the intestine?
increases Ca absorption but requires vit D3 (25(OH)D)
what effect does PTH have on bone?
increases osteoclast activity causing release of calcium
symptoms of hypercalaemia
Stones (renal)
Bones (bone pain)
Groans (abdominal pain, nausea and vomiting)
Thrones (polyuria)
Psychiatric overtones (confusion and cognitive dysfunction, depression, anxiety, insomnia, coma)
secondary hyperparathyroidism
PTH high
Ca low
phosphorus high
CKD-> chronic low Ca-> stimulation of PT. also due to malabsorption/ vitamin D deficiency
tertiary hyperparathyroidism
PTH very high
Ca high
phosphorus high
due to long secondary hyperparathyroidism. Ca low
phosphorus high
CKD-> chronic low Ca-> stimulation of PT-> hypercalcaemia
primary hyperparathyroidism
PTH high
Ca High
phophorus low
what hormones does the adrenal cortex produce?
- mineralocorticoids- e.g. aldosterone
- glucocorticoids (anti-inflammatory e.g. cortisol)
- androgens (oestrogen/ tesetosterone)
what is the function of aldosterone
raises blood sodium and lowers K by acting on distal tubule of the kidney
how is angiotensin II produced?
decreased renal perfusion-> increased renin released
angiotensinogen from liver-> converted to angiotensin I by renin-> converted to angiotensin II by ACE on lung/ renal epithelium
effects of angiotensin II
increased H2O and salt retention therefore increased circulating volume (1. increased sympathetic activity, 2. arteriole constriction, 3. ADH secretion from post pituitary-> H20 reabsorption 4. aldosterone secretion)
aldosterone has what effect?
NaCl resorption and K excretion in kidneys
what is ACTH?
adrenodorticotropic hormonr: produced by anterior pituitary, releases cortisol
when should cortisol be measured?
8-9am
which hormones make up the management of addison’s?
hydrocortisone- (glucocorticoid)
fludrocortisone- (mineralocorticoid)
2 main causes of Addison’s?
AI disease
TB
How would an Addisonian crisis present?
severe hypotension/ dehydration
give Na and aldosterone replacement in CCU
what abnormal results may be shown on bloods in Addisons?
Na low K high Glucose low ACTH simulation- low rise in cortisol 08:00 cortisol low 08:00 ACTH low/ high depending on secondary/ primary hypercalcaemia anaemia
when should steroid dose be increased in Addisons?
doubled if intercurrent illness
take more day before strenuous exercise
hypopituitarism causing addison’s (low cortisol and low ACTH) what else should you check?
T4 for hypothyroid
symptoms of cushings
moon face, buffalo hump, HTN, osteoporosis, striae, acne, hirstuism, amenorrhoea
which cancer most commonly causes hypercalcaemia?
SCC lung (releases PTH related peptide)
peptic ulceration, galactorrhoea, hypercalcaemia
multiple endocrine neoplasia 1
hypercalcaemia, thyroid cancer and phaeochromocytoma
MEN 2
hypertension
hypokalaemia (e.g. muscle weakness)
alkalosis
Conn’s- hyperaldosteronism
pituitary adenoma causes what visual field loss
bitemporal hemianopia
which hormones may a pituitary adenoma secrete?
prolactin
ACTH (causing cushings)
GH
may also be non-secreting and compress normal tissue leading to insufficiency of these
what would a pituitary blood profile entail
GH, prolactin, ACTH, FH, LSH and TFTs
reducing cholesterol by 10% gives what % reduction in CVD risk
20% reduction in cardiovascular disease risk after 3 years
what factors would make you query familial hypercholeserolaemia?
age <30
FHx
total cholesterol >7.5
other than lifestyle/ genetic: 3 risk factors for hyperlipidaemia
hypothyroid
T2DM
medications (BB, thiazides, corticosteroids, COCP, antipsychotics)
what other bloods should you do in raised cholesterol?
fasting BM
U+E
LFT
TSH
what is the target total cholesterol?
<4mmol/L
side effects of statins
myalgia
GI upset
abnormal LFT
do LFT and CK baseline and repeat 4-8 weeks
symptoms of hypocalcaemia
muscle weakness and cramp/ tetany, numb fingers, convulsions, arrhythmias, stridor
most common causes of hypoparathyroidism
post-surgical, AI, radiotherapy of neck
most common type of thyroid cancer
papillary, often young female, good prognosis
single thyroid nodule
follicular adinoma (toxic thyroid nodule if produces hyperthyroidism)/ carcinoma
thyroid cancer with raised calcitonin
medullary cancer
illness-> hyperthyroid then hypothyroid when illness settles
De Quervain’s thyroiditis
hypopituitarism may present as?
GH-stunted growth prolactin ACTH- low BP , increased thirst/ urination FH, LSH- irregular periods/ amenorrhoea TFTs- Hypothyroidism
hypopituitarism can be caused by
tumours
radiation/ chemo/ surgery
TB/ meningitis
traumatic bleed
what is a pheochromocytoma?
neuroendocrine tumour of chromaffin cells of adrenal medulla. often cause HTN/ hyperglycaemia. found in MEN
congenital adrenal hyperplasia
excess androgen production, masculinization of women, feminization of men, or precocious sexual development in children
hypoaldosternism
fluid and salt loss
hyperkalaemia
abnormal growth of hair on a woman’s face and body.
hirsuitism, caused by increased androgens
Hyperosmolar hyperglycemic nonketotic coma
signs of dehydration, weakness, legs cramps, vision problems, and an altered level of consciousness.
causes of diabetes insipidus
(ADH insufficiency/ insensitivity) head injury pituitary surgery idiopathic high Ca, low K Li genetic
diabetes insipidus presentation
polyuria/ polydipsia
diabetes insipidus investigation
high plasma osmolality, low urine osmolality
SIADH causes
SCC lung
stroke, subarachnoid
infection-TB
drugs- SSRI/TCA/sulfonylureas
SIADH presentation
hyponatraemia secondary to the dilutional effects of excessive water retention
