Endocrine Diseases Flashcards
What are water soluble hormones?
- stored in vesicles
-unbound transport
-bind to surface receptor
-fast clearance
What are the types of water hormones?
-TRH,LH,FSH
What are fat soluble hormones?
-synthesised on demand
-protein bound
-diffuse into cell
-slow clearance
What are the types of fat soluble hormones?
What are the types of fat soluble hormones?
steroids - cortisol
What are the peptide hormones?
TRH, Gonadotrophins
What are the amine hormones?
Dopamine
Epinephrine
Noradrenaline
Adrenaline
What hormones does the anterior pituitary gland release?
FSH+LH
ACTH
GH
TSH
Prolactin
What is the mechanism of FSH + LH?
Hypothalamus- GnRH-AP-FSH/LH- ovaries +testes
What does FSH act on?
granulosa cells to produce oestrogen and Sertoli cells to stimulate spermatogenesis
What does LH act on?
theca cells to produce androgens and leydig cells to produce testosterone
What is the ACTH mechanism?
Hypothalamus - corticotropin releasing hormone- AP- adrenocorticotropic hormone - adrenal cortex (zona fasciulata). -gluccocorticoid -cortisol
What is the function of cortisol?
- increases protein and carbohydrate breakdown
2.vasoconstriction - suppresses inflammatory dn immune response
4.inhibits non essential factors
What is the mechanism of GH?
Hypothalamus - Growth hormone releasing hormone - AP - GH- liver- IGF-1 production
How is insulin released?
Biphasic - released in two phases
1. Increase peripheral glucose uptake (glucose-> glycogen)
Glucose binds to GLUT2 receptors on pancreas, stimulating insulin release
2. Insulin binds to peripheral insulin receptors - activates intracellular tyrosine kinase + cascade
Result = increased Glut-4 channel expressing on cell membranes to increase peripheral uptake
What is the mechanism for TSH?
Hypothalamus - TRH- AP-TSH - T3+T4 - carried in blood bound to thyroglobullin binding protein
What are the functions of T3+T4?
- food metabolism
-protein synthesis
-increased sympathetic action
-heat production
-needed for growth and development
What is the mechanism of prolactin?
Hypothalamus - dopamine - AP - Prolactin - milk production and breast development
What is released at the post pituitary ?
Oxytocin - milk ejection + labour induction
Vasopressin - recruited when low blood volume, stress
-vasoconstriction
-increase aldosterone
What does the zona glomerulosa release?
aldosterone
What does zone reticualris release?
Androgens
What does the adrenal medulla secrete?
Adrenaline , noradrenaline
What can pituitary tumours cause?
- press on local structures - optic chiasm
-hypOpituitarism
-hypERpituitism - acromegaly, cushings, prolactinoma
What are the types of diabetes?
T1Dm
T2DM
MODY- Maturity onset diabetes of the young
LADA- latent autoimmune diabetes in adults
What are secondary causes of diabetes?
Acromegaly + cushings
Haemachromatosis
Thiazides/ corticosteroids
What is type 1 diabetes?
Type 4 hypersensitivity; autoimmune destruction of pancreatic B cells leading to absolute insulin deficiency
What is the epidemiology of T!DM?
- Young patients
-lean
-North European descent
What are the risk factors of T1DM?
- HLA DR3/ HLA DR4
-other autoimmune diseases
-environmental infection
What is the pathology of T1DM?
Autoimmune beta islet destruction = absolute or very low insulin therefore -hyperglycaemia,
-low cellular glucose so increase in lipolysis and gluconeogenesis
-hyperkalamia even though total body K+ is low as insulin stores K+ into cells via Na+/K+ATPases
What is the presentation of T1DM?
Lean young patient with polydipsia, nocturia, polyuria, polyphagia and weight loss
Glycosuria +/- sigs of ketogenesis
What is the diagnosis of T1DM?
random blood glucose= >11.1 mol/L = T1DM
Fasted blood glucose = >7mmol/L = T1DM
HbA1C= 48mmol/L or >6.5% = T1DM
What are the normal levels for RBG, FBG and HbA1C?
<11.1mmol/L - normal RBG
<6.0mmol/L - normal FBG
<6% - normal Hb1AC
What is the Hb1AC level for pre-diabetes?
5.7%- 6.4%
What is the treatment for T1DM?
Basal bolus Insulin
Basal = longer acting, to maintain stable insulin levels throughout the days
bolus= faster acting, 30mins pre-prandial to give ‘insulin spike’
What are the different types of insulin?
rapid -novorapid
short- regular insulin
intermed- NPH
long- glargine
What is the main complication of T1DM?
Diabetic ketoacidosis
What are the causes of DKA?
poorly managed T1DM, infection/illnesses
What is DKA?
increasing hyperglycaemia and rising ketones
What is the presentation of DKA?
10 -years old
-presents to a&e with severe dehydration and a history of T1DM.
Sx:
-kussmaul breathing (deep laboured breaths to blow off CO2)
-Pear drop breath (fruity ketone breath smell)
-Reduced tissue turgor, hypotension and tachycardia
what is the pathology of DKA?
Absolute insulin deficiency = unrestrained lipolysis + gluconeogenesis. So much gluconeogenesis that not all glucose is usable so it is converted to ketone bodies(increase in acidic concentration = ketoacidosis)
What is the diagnosis of DKA?
Ketones - blood >3mmol/L
Hyperglycemic >11.1mmol/L
Acidosis (met) <7.3pH or >15mmol HCO3-
+Ketonuria, glycosuria and hyperkalaemia
What is the treatment for DKA?
ABCDE - emergency
1st line - always fluid - dehydration
then insulin (+glucose to prevent hypoglycaemia and K+ to replenish potassium stores)
What is type 2 diabetes?
Peripheral insulin resistance with peripheral insulin deficiency - carbohydrates, lipids and beta amyloid deposits in pancreas
What are the risk factors for T2DM?
-FHX
-smoking
-obesity
-HTN
-sedentary lifestyle
What is the pathology of T2DM?
peripheral insulin resistance (malfunctional insulin intracellular activation pathway) therefore decrease in GLUT4 expression , and minor destruction to pancreatic islets due to deposition.
Results in hyperglycaemia and increase in insulin demand from depleted B cell population.
What is the presentation of T2DM?
obese, hypertensive, older, with polydipsia, polyuria, nocturia, glycosuria
Aconthisis nigricans - dark pigmented skin folds -severe insulin resistance
What is the diagnosis of T2DM?
same as T1DM:
FBG: >7mmol/L
RBG >11.1mmol/L
HbA1C >6.5%/ 48<
What are the pre diabetes states?
IGT - impaired glucose tolerance test
IFG-impaired fasting glucose
What are the results of IGT?
normal FBG >6mmol/L
2hr OGTT - 7.8-11mol/L - pre diabetic
What are the results for IFG?
FBG- 6.1-6.9 mmol/L
normal 2hr OGTT <7.8 mmol/L
What are the normal ranges for OGTT?
oral glucose tolerance test
normal - <7.8mmol/L
pre-diabetic 7.8-11
diabetic >11.1
what are the normal ranges for FBG?
normal - <6
prediabetic 6.1 - 6.9
diabetic >7
What are the ranges for RBG?
normal <11.1
Diabetes >11.1
What are the ranges for Hb1AC?
normal - <42/<6%
pre-diabetic 42-47/ 6-6.4%
Diabetics >48/ >6.5%
What is the treatment for T2DM?
if pre-diabetic = lifestyle changes to diet and exercise
Diabetic =
1. metformin(increase peripheral sensitivity to insulin)
2. If Hb1AC 58+ - add sulfonylureas (gliclazide)
3. Still high - consider 3rd drug - DPP4 inhibitor, SGLT-2 inhibitor
4. Give insulin
Do you gain or lose weight on Metformin, gliclazide, DPP4, glitazones?
metformin - lose
gliclazide- gain
DPP4 inhibitors - no change
Glitazones - gain
What is the main complication of T2DM?
Hyperosmolar hyperglycaemic state
What is the pathology of HHS?
excessive hepatic gluconeogenesis not totally insulin deficient therefore ketosis doesn’t occur
- glucose osmotically active therefore excessive glucose = hyperosmolar blood
What is the presentation of HHS?
severe T2DM, low consciousness
What is the diagnosis of HHS?
Heavy glycosuria, increase plasma osmolarity(>300mmol/L) with hyperglycaemia - no ketonuria
What is the treatment of HHS?
- insulin ( and potassium and glucose)
- Iv fluid - saline
-LMWH- anticoagulant as they have thicker blood
What are DM microvascular complications?
retinopathy, neuropathy( Charcot foot), nephropathy (nephrotic syndrome, CKD)
What are DM macrovascular complications?
Cardiovascular (MI), cerebrovascular (stroke), peripheral arterial disease (PVD)
What is hypoglycaemia ?
Abnormally low blood glucose
What are the causes of hypoglycaemia ?
often resulting from diabetes drugs; sulfonylureas or insulin
Non diabetic - oral, liver failure, Addisons
What do sulfonylureas do?
stimulate increased insulin production and secretion
What is the presentation of hypoglycaemia ?
decreased consciousness, dizziness, sometimes will faint
What is the treatment for hypoglycaemia?
IV glucose - IM glucagon
Where does the thyroid sit?
C5-T1
2 lobes connected with isthmus
Where does the inferior thyroid artery arise from?
off thyrocervical trunk
Where does the superior thyroid artery arise from?
off external carotid artery
What are the follicular cells?
Iodine trapping - from circulation
What is the colloid?
Synthesis of T3+T4 - produces thyroglobulin
What is the T3+T4 process?
- iodine trapped diffuses into colloid
-binds to tyrosine residues on thyroglobulin, using TPO enzyme catalyst
-T1or T2
-TSH - Rbinding= stimulates T1+2 release
T1+T2= T3
T2+T2 = T4
What is hyperthyroidism?
Excess thyroid hormone in the blood
What is the most common cause of hyperthyroidism?
Graves disease
What are other causes of hyperthyroidism?
- toxic multinodular goitre
-ectopic TSH secretion
-toxic adenoma
-drugs= amiodarone, iodine
-de quervains thyroiditis - post viral infection
What is the epidemiology of hyperthyroidism?
common in females
What is the pathology of hyperthyroidism?
TSH- R autoantibodies - excessively stimulate thyroid
What are the symptoms of hyperthyroidism?
- heat intolerance
-diarrhoea
-weight loss
-hyperphagia
-anxiety
-oligomenorrhoea
What are the signs of hyperthyroidism?
-Goitre
-tacycardia
-pretibial myxoedema
- muscle wasting
-fine tremor
What is the diagnosis of hyperthyroidism?
Graves = TSH-R antibodies positive
Thyroid functioning tests:
-low TSH - High T4= primary hyperthyroid - graves
-high TSH -High T4 = secondary hyper
-High TSH - T4=subclinical hypothyroid
-Low TSH - T4= subclinical hyperthyroid
Anti-TPO Ab’s - more in hypo
Thyroid USS - tmg vs graves
What is the treatment for hyperthyroidism?
1st line - carbimazole(CI in pregnancy) + propranolol alongside
-radioactive 131iodine; definitive treatment - destroys excess thyroid tissue (CI in pregnancy)
-surgery
What is a side effect of carbimazole?
agranulocytosis - presents as sore throat
what is a complication of hyperthyroidism?
thyroid storm - rapid deterioration thyrotoxicosis - high level of T4- systemic decompression;AF,HTN and coma, heart failure, osteoporosis
What is the treatment of Thyroid storm?
propylthioruracil + KI
What is graves disease?
Autoimmune condition , that causes hyperthyroidism
What is the pathology of graves disease?
increased levels of TSH receptor stimulating antibody
What is the presentation of graves?
- opthhalmopathy - bulging eyes
-Dermopathy - pretibial myxedema
-characteristic rash - acropachy
What is hypothyroidism?
Lack of thyroid hormone
What is the epidemiology of hypothyroidism?
women
ageing
postpartum
What is the main cause in the developed world?
Hashimotos Thyroiditis
What is hashimotos thyroiditis?
Autoimmune thyroid destruction
What is the main cause in the developing world?
iodine deficiency
What are other causes of hypothyroidism?
post part rum thyroiditis
-amiodarone
-secondary causes - hypopituitarism
What is post part rum thyroiditis?
same mechanism as hashimotos but
1- acute - presents during pregnancy
2-resolves by itself after a year of Sx
What is the pathology of hypothyroidism?
Anti-tpo (thyroid peroxidase) antibodies high vs thyroid
What are the symptoms of hypothyroidism?
cold intolerance, constipation, weight gain, lethargy , menorrhagia
What are the signs of hypothyroidism?
bradycardia, slow reflexes, cold hands, Goitre, pretibial myxoedema
What is the diagnosis of hypothyroidism?
TFTs:
-High TSH - Low T4= primary hypothyroidism
-Low TSH- Low T4 = secondary hypothyroidism
-High TSH - T4 =subclinical hypothyroidism
Anti-TPO antibodies high - in hashimotos
-typically anaemic - any type
What is the treatment for hypothyroidism?
Levothyroxine(T4) - careful with dose, can cause iatrogenic hyperthyroidism
What is a complication of hypothyroidism?
Myxoedema coma(often infection precipitated); rapidly decrease T4
What is the presentation of myxoedema coma?
hypothermia, loss of consciousness , heart failure
What is the treatment myxoedema coma?
Levothyroxine
Abx + hydrocortisone - until adrenal insufficiency has been ruled out
What are the types of thyroid carcinomas?
Papillary -mc
Follicular
Anaplastic - mets the most
Lymphoma
medullary cell
What is the behaviour, spread and prognosis of papillary ?
young
local spread
good prognosis
What is the behaviour, spread and prognosis of Follicular ?
middle age
Spread to lung/bone
usually good prognosis
What is the behaviour, spread and prognosis of anaplastic?
aggressive
local spread
very poor prognosis
What is the behaviour, spread and prognosis of lymphoma?
variable behaviour
usually poor prognosis
What is the behaviour, spread and prognosis of medullary cells?
familial
Local and metastasises
poor prognosis
Where does thyroid carcinomas metastasise to ?
Lung -50%
Bone-30%
liver-10%
brain-5%
What is the presentation of thyroid carcinomas ?
mostly present at thyroid nodules - hard + irregular
- local compression -hoarse voice
-dysphagia
-any metastasises
What is the diagnosis of thyroid carcinoma?
Fine needle aspiration biopsy
TFts, ultrasound thyroid
What is the treatment of thyroid carcinomas?
papillary + follicular = thyroidectomy + radioactive given
Anaplastic + lymphoma = palliative mostly
What is cushings syndrome?
Refers to the abnormalities resulting from excess cortisol from any cause
What is cushings disease?
Used to describe the clinical state of free circulating glucocorticoids , occurs when a pituitary adenoma secretes excess ACTH
What are the ACTH dependent causes of cushings syndrome?
Cushing disease - mc
ectopic ACTH - sclc
What are the ACTH independent causes of cushings syndrome?
steroid use -mc overall cause
adrenal adenoma
What is the pathology of cushings syndrome?
Corticotrophin releasing hormone typically released with a circadian rhythm (high in morning, low at night)
Here, this rhythm is lost - excessive unregulated CRH, ACTH,Cortisol
What is the ACTH mechanism?
hypothalamus - crh - pituitary - ACTH - adrenal gland - cortisol
What is the presentation of cushings syndrome?
moon face
central obesity
purple abdo striae
osteoporosis
thin easy bruising skin
plethoric complexion
easy infections
muscle atrophy
What is the diagnosis of cushings?
Rule out oral steroids- if on steroids =STOP
FIRST LINE:
-Random serum cortisol high (at 12 am should be at its lowest) then FIRST LINE test:
-Dexamethasone suppression test - in a healthy patient should have negative feedback
-measure cortisol before and after
-if suppressed >50nmol/L= non cushings
-no suppression =cushings
-If first line positive then measure plasma ACTH
-high ACTH = ACTH dependent cause so look for cushings disease on pituitary MRI
-Low ACTH - ACTH independent cause - consider adrenal adenoma
What is the dexamethasone suppression test?
Dexamethasone = essentially cortisol therefore in a healthy patient should negative feedback HPA axis and lower cortisol
1. measure cortisol level then give dexamethasone measure, over night
2. measure cortisol 8hr after
-non cushings - suppression (>50nmol/L)
-cushings- little/ no suppression
What is the treatment for cushings disease?
transphenoidal resection or bilateral adrenalectomy
What is a complication of bilateral adrenalectomy?
Nelson’s syndrome; pituitary tumour will continue to enlarge with no negative feedback from adrenals- increased ACTH + skin hyperpigmentation
What is the treatment for adrenal adenoma?
unilateral adrenelectomy
What is the treatment for ectopic ACTH?
surgical removal - SCLC
What is a complication of cushings?
osteoporosis, secondary DM
What is adrenal insufficiency?
Autoimmune destruction of the entire adrenal cortex in primary adrenal insufficiency or HPA axis suppression in secondary adrenal insufficiency . Resulting in mineralocorticoid, glucocorticoid and androgen deficiency.
What are the primary causes of adrenal insufficiency?
main cause in developed world - Addisons
main cause in developing world - TB
What are the secondary causes of adrenal insufficiency?
Iatrogenic - suppression of HPA axis from steroids
What are other causes of adrenal insufficiency?
adrenal mets - lung, liver,breast
Adrenal haemorrhage
What is the pathology of Addisons?
Addison’s destroys adrenal cortex by autoantibodies therefore high ACTH and low adrenal hormones. High ACTH stimulates proopiomelanocortin (melanocytes) resulting in hyperpigmentation
What is the pathology of HPA suppression?
HPA suppression therefore low ACTH and low Adrenal hormones and no hyperpigmentation
What is the presentation of adrenal insufficiency?
Lethargy,
weight loss
postural hypotension
vitiligo
change in body hair
hyperpigmentation (1)
hypoglycaemia
Abdo pain + vomiting
What is the diagnosis of adrenal insufficiency?
Short synACTHen test:
Test adrenal reserve; 1. measure basal cortisol at 9am
2.administer synacthen
3. sample cortisol again after 30 min
If plasma cortisol >580nmol/L after 30 min EXCLUDE Addisons
-Auto 21-d hydroxylase Ab’s
-bloods
-CXR for TB if suspected
-High ACTH(9am) in primary but low in secondary
\What is the treatment for adrenal insufficiency?
Hydrocortisone, fludrocortisone
If trauma/ infection. Double dose of hydrocortisone
What is adrenal crisis?
Severe adrenal insufficiency especially hydrocortisolemia, ; N+v, renal failure, level of consciousness
What is the treatment for adrenal crisis?
immediate hydrocortisone +IV saline + dextrose if hypoglycaemic
What is acromegaly?
Excess growth hormone- HGH in adults (after epiphyseal fusion)
Gigantism in children (before epiphyseal fusion)
What are the causes of acromegaly?
Functional pituitary adenoma
or ectopic GH releasing hormone from a carcinoid tumour
What is the pathology go acromegaly?
Hypothalamus –> GHRH–> anterior pituitary–> GH–> liver-IGF-1 which exerts effects on rest of body
In acromegaly high IGF-1 (produced by liver)
What is the presentation of acromegaly ?
Large hands/feet, box jaw, change in vision (bitemporal hemianopia), sleep apnoea (increase in larynx soft tissue), large interdental gaps, carpal tunnel syndrome , IGT - risk of T2DM
What is the diagnosis of acromegaly?
IGF-1 serum level high - always first line screening
Impaired glucose tolerance is gold standard - OGTT
What is the treatment of acromegaly?
1st line - transsphenoidal surgery
otherwise : somatostatin analogue - octreotide
dopamine agonist - bromocriptine
GH agonist. -pregvisomant
What is the complication of acromegaly?
T2DM, sleep apnoea
What is hyperprolactinemia?
Most common in females, high serum prolactin
What are the causes of hyperprolactinoma?
prolactinoma, drugs(ecstasy) -mc
what is the presentation of hyperprolactinoma?
Amenorrhoea, galactorrhea, sexual dysfunction, decreased libido, erectile dysfunction, decreased testosterone , bitemporal hemianopia
What is the diagnosis of hyperprolactinoma?
high serum prolactin
What is the treatment fro hyperprolactinoma?
dopamine agonists- bromocriptine - shrinks tumour as dopamine inhibitor of prolactin
What is conns syndrome - hyperaldosteronism?
Excess aldosterone independent of RAAS
What is the most common secondary cause of hypertension?
hyperaldosteronism
What are the causes of hyperaldosteronism?
2/3 - adrenal adenoma (Conn’s)
1/3- bilateral adrenal hyperplasia
What is the cause of secondary hyperaldosteronim?
excess renin which increases aldosterone
What is the pathology of hyperaldosteronism?
increase in aldosterone = increase in Na+ / H2O and decrease in K+, hypertension with hypokalaemia
What is the presentation of hyperaldosteronism?
resistant hypertension -unfixable with ACE-i/BB
hypokalaemia; muscle weekness, parasthesia, polydipsia, polyuria
What is the diagnosis of hyperaldosteronism?
1st line - aldosterone:renin high
Diagnostic = high serum aldosterone not surpassed with Iv saline or fludrocortisone
Hypokalemia - ECG( prolonged PR, ST depression, flat t waves)
What is the treatment for hyperaldosteronism?
Surgery - laparoscopic adrenelectomy
Spironolactone - aldosterone antagonist
What is diabetes inspidus?
Tool little ADH from posterior pituitary gland or kidneys aren’t responding to ADH.
What are the 2 types of diabetic inspidus?
cranial - low ADH secretion
Nephrogenic - decreased kidney response to ADH
What are the causes of cranial diabetic inspidus?
ADH gene mutation, pituitary adenomas, idiopathic
What are the causes of nephrogenic diabetic inspidus?
Renal tubular acidosis, ADH-R mutation, polyuria
What is the pathology of diabetic insipidus ?
Low ADH, increased H2O losses in urine; dilute high volumes
What is the presentation of diabetic insipidus?
polyuria, polydipsia, hypernatramia, lethargy, confusion, severe dehydration
What is the diagnosis of diabetic insipidus?
- 3+ L urine daily = suspect
1- Water deprivation test(no fluid for 8hr)- Serum osmolality stays normal, urine osmolality high - normally
Serum osmolality rises while urine is unchanged - DI
2-Inject IM desmopressin (differentiate cranial + nephrogenic)
How do you differentiate between cranial and nephrogenic urine osmolality?
Inject IM desmopressin:
Cranial urine osmolality :Before<300= low after High >800 - adequate ADH to have effect on kidney
Nephrogenic urine osmolality before <300 low after <300 low - ADH has no effect on kidney
What is the treatment for diabetes insipidus?
Cranial - desmopressin
Nephrogenic - thiazides - increase H2O loss at DCT therefore encourages increase Na+ uptake and H2O retention which will concentrate urine and increase retention volume
What is syndrome of inappropriate ADH, (SIADH)?
Inappropraitely released ADH; dilute euvolemia
-cause of hyponatremia
How does SIADH cause hyponatremia?
excess ADH = more water retention therefore compensatory Na+ excretion to maintain euvolemia
What are the causes of SIADH?
S- sclc
I- infection/ immunocompromised -TB
A-abscesses
D- drugs-SSRI,
H-head trauma
What is the pathology of SIADH?
increased ADH, independent of RAAS- increased vessel vasoconstriction therefore increased BP
-increased ADH increased aquaporins - increases water retention therefore blood volume- excess H2O retained means more dilute blood and more Na+ loss
What is the presentation of SIADH?
Sx of hyponatremia
- vomiting, headache, low consciousness (decreased GCS), muscle weaknesss
Low Na+ -seizures, neurological complications ;brainstem herniation
What causes a brainstem herniation?
low Na+ means high compensatory H2O; enters skull = increased ICP
- causes hyponatremic encephalopathy
-risk of brainstem herniating through Forman magnum (tentorial herniation)
What is the diagnosis of SIADH?
Low Na+ and normal K+ serum
- high urine osmolality - concentrated urine and dilute serum
DDx- Na+ depletion - give IV saline - if serum normalises = Na+ depletion if it doesn’t =SIADH
What is the treatment for SIADH?
Fluid restrict + hypertonic saline to concentrate blood
Treat underlying cause - tumour excision
Chronic cases - Drugs; furosemide, vasopressin antagonist
What is a carcinoid tumour?
malignant tumour of enterochromaffin cells which produce 5-HT/serotonin
- only the neoplastic cells no symptoms
What is carcinoid syndrome?
When carcinoid tumour metastasises to liver, constellation of Sx
Where are the carcinoid tumours?
Mostly GIT at appendix and terminal ileum- also can be lungs
What is the presentation of carcinoid syndrome?
Flushing, diarrhoea, tricuspid incompetence (valve lesion)
may have RUQ pain, respiratory problems
What is the diagnosis of carcinoid syndrome>
Liver USS - positive mets
increase In 5-Hydroxyindoleacetic acid in urine - major 5HT metabolite - GS
CT/MRI to locate primary tumour
What is 5HT?
5- hydroxytryptamine (serotonin)
What is the treatment of carcinoid syndrome?
Surgically excise primary tumour - definitive
octreotide (somatostatin analogue) - can block tumour hormones
What is a complication of carcinoid syndrome?
carcinoid crisis; life threatening Sx constellation
What is the treatment for carcinoid crisis?
SST analogue - octreotide - high dose
What is pheochromocytoma?
Adrenal medullary tumour , secretes catecholamines (Adr,NAd)
What are the causes of pheochromocytoma?
usually inherited associated with
- Men 2a +2b (multiple endocrine neoplasia)
-neurofibromatosis 1 - tumours deposited along nerve myelin sheath
What is MEN2?
A rare, genetic disorder that affects the endocrine glands and can cause tumors in the thyroid gland, parathyroid glands, and adrenal glands.
What is the presentation of pheochromocytoma?
hypertension, pallor, very sweaty, tachycardic
What is the diagnosis of pheochromocytoma?
plasma metanephrines + normetanephrines - diagnostic
- more sensitive readings than NAd/Adr as longer half life
- urinary catecholamines
- CT image tumour
What is the treatment of pheochromocytoma?
Drugs - alpha blocker first (phenozybenzamine) then beta blocker - atenolol - prevents reactive vasoconstriction
- surgery - excise tumour
What are metanephrines?
made when your body breaks down hormones called catecholamines
metanephrines and normetanephrines are metabolites of the catecholamines
What are the complications of pheochromocytoma?
HTN crisis (180/20 + BP)
causes - XR contrast, TCA, opiates
Treat -phentolamine - alpha blocker
What is the parathyroid gland?
4 glands on posterior aspect of thyroid - very sensitive to change in calcium
What is the action of the parathyroid gland?
- Parathyroid hormone released when low calcium, negative feedback by increased calcium and by calcitonin
- PTH inhibits osteoprotegerin (which competes with Rank-L) therefore allows Rank -L signalling from osteoblasts - osteoclasts - bone resorption
-PTH acts on kidney to convert 25-hydroxycholecalciferol to its active form1,25 dihydroxyvitamin D -which increases calcium and phosphate gut absorption and decreases calcium and phosphate excretion at DCT
PTH- increases intestinal calcium absorption and at the kidneys and increases phosphate excretion at kidneys
What is hyperparathyroidism?
Parathyroid gland produce too much parathyroid hormone
What are the primary causes of hyperparathyroidism?
excessive PTH secretion usually caused by parathyroid adenoma (or sometimes parathyroid hyperplasia) - mc (hyperparathyroid–> hypercalcaemia
What is the secondary cause of hyperparathyroidism?
physiological compensatory hypertrophy of all parathyroids in response to hypocalcaemia , vitamin deficiency or chronic kidney disease
What is the tertiary cause of hyperparathyroidism?
Glands become autonomous, producing excess PTH even after the correction of calcium deficiency. occurs after many years of secondary hyperparathyroidism .
What is the malignant cause of hyperparathyroidism?
neoplasms (squamous cell lung cancer, breast, renal) secrete PTHrp; ectopically mimics PTH
What is the presentation of hyperparathyroidism?
Hypercalcemia
- bones (excess resorption therefore osteopenia), stones (kidney stones), Groans(abdo pain and constipation) and psychedelic moans (depression and anxiety)
What is the diagnosis for primary hyperparathyroidism?
- high PTH
-high calcium
-low phosphate
-high ALP - alkaline phosphate
What is the diagnosis of secondary hyperparathyroidism?
- high PTH
-low calcium
-high phosphate
-high ALP
What is the diagnosis of tertiary hyperparathyroidism?
- high PTH
-high calcium
-high phosphate
-high ALP
What are other tests needed to diagnose hyperparathyroidism?
XRKUB- renal stones
DEXA scan - bone density
U+Es - access renal function
ECG- short QT - hypercalcaemia
What is the treatment for hyperparathyroidism?
primary = removal of PTH adenoma/ parathyroidectomy of all 4 glands
secondary/tertiary = treat cause
malignant = remove tumour
What is a complication of hyperparathyroidism?
Acute severe hypercalcemia
How do you treat acute severe hypercalcemia?
- give IV fluids + bisphosphonates
What is more common hypoparathyroidism or hyperparathyroidism?
Hyper most common
What is the primary cause of hypoparathyroidism?
PTH gland failure
- Di George syndrome –> familial, PTH glands failed to develop
-idiopathic
What is the secondary cause of hypoparathyroidism?
- after surgery (parathyroid/ thyroidectomy) - most common
What is pseudohypoparathyroidism?
- peripheral PTH resistance
-short stature + small 4th/5th metacarpals
What are the symptoms of hypoparathyroidism?
- hypocalcemia
-CATS go numb
-Convulsions, arrhythmia ,tetany, numbness
What are the signs of hypoparathyroidism?
Hypocalcemia signs:
-Chvostek’s (twitching of facial muscles when CN7 tapped over parotid)
-Trousseau’s - carpopedal spasms when applying tourniquet to forearm
What is the diagnosis of hypoparathyroidism?
- low PTH
-low calcium - high phosphate
-ECG; long QT
What is the treatment for hypoparathyroidism?
- calcium supplements + vitamin deficiency supplements -AdCalD3
What are the causes of hypercalcemia?
- hyperparathyroid
-bone malignancy
-Drugs- thiazides
-Excess Ca++ intake
-hyperthyroid
-dehydration
What is the diagnosis for hypercalcemia?
-serum calcium >2.6mmol/L
ECG - long QT
- low PTH due to negative feedback except in hyperparathyroid
What is the presentation of hypercalcemia?
BONES - pain, osteoporosis
STONES - kidney stones
GROANS - abdominal pain + constiaption
PSYCHEDILIC MOANS - anxiety+ depression
+decrased muscle tone + contractions
What are the causes of hypocalcemia?
- CKD( low vit D activation)
-Severe vitamin D deficiency
-hypoparathyroidism
-Drugs - bisphosphonates
What is the diagnosis for hypocalcemia?
Serum calcium <2.1mmol/L
ECG - short QT
-PTH always high except in hypoparathyroidism
What is the presentation of hypocalcemia?
CATs go numb
- convulsions, arrhythmias, tetany, numbness
Chvosteks signs
Trousseau’s sign
- increased muscle tone + contractions
What are the causes of hyperkalemia?
-AKI
-Drugs - NSAIDs,Spironolactone, ACEi
-Addisons
-DKA
-increased intake
What is the pathology of hyperkalemia?
Increased potassium decreases threshold action potential therefore easier depolarisation + abnormal heart rhythms
What is the presentation of hyperkalamia?
- fast irregular pulse
-myalgia - muscle aches and pains
What is the diagnosis of hyperkalemia?
U+E = >5.5mmol/L - hyper
>6.5mmol/L - medical emergency
ECG:
-absent p waves
-prolonged PR
-Tall tented T waves
-Wide QRS
What is the treatment for hyperkalemia?
if urgent - calcium gluconate - stabilise cardiac membrane then insulin and dextrose
Non urgent- insulin and dextrose
What are the causes of hypokalaemia?
- Thiazides and loop diuretics
-Conns
-Renal tubular acidosis
GI losses
-decreased intake
What is the presentation of hypokalaemia?
hypotonia, hyporrefelxia , arrhtymias - AF
What is the diagnosis for hypokalemia?
U+Es - <3.5mmol/L- hypo
<2.5mmol/L - emergency
ECG:
-small inverted T waves
-prominent u waves
-ST depression
-PR prolongation
What is the treatment for hypokalaemia?
K+ replacement
-aldosterone agonist - spironolactone