Endocrine Flashcards
How to Dx. Di
- 8 hwater deprivation test
Normal > 600mmols/l
DI - <300 mmil/l - Desmopressin 2 mg IM IV
Central - > 800 mmols/l
Nephrogenic - no correction
What is the plasma and urine osmolarity in DI
plasma osmolarity is HGIH
urine osmolarity LOW
Na levels in DI and clinical findings
HYPERNATREMIA
- lethargy
- confusion
- coma
- fits
Ddx DI
DM polyuria psychological DIURETICS LITHIUM PROSTATIC HYPERTROPHY
Screening for cause DI
Centra: MRI and pituitary function test
Nephroenic
- U/E
- Calcium
- Renal ULTRASOUND
Treatment for DI
Centra - mild - increase fluid intake
moderate- desmopressin and DDAVP (at lowest dose to control symp)
Nephrogenic - tx underlying disease
Diuretics - BENDOFLUMETHIAZIDE and NSAIS (prostaglandin inhibits Na )
side effect DDAP
can worsen MI in susceptible patients
Hyponatremia
untreated DI
hypernatremia
CV collapse
dehydrate
death
complications of acromegaly
vle
Heart : HTn , CM , LVH , HF Pancreas: DM Lungs: sleep apnea , pulm HTN Arthritis Neuro - HEADACHE , cerebral vascular events MISCILLANEOUS - carpal tunnel - colon polyps/ Ca Hypopituitarism Pyperprolactinemia Carpel tunnel
DI screening test
Elevated serum IGF-1 levels
DI diagnostic test
OGTT
GH is normally inhibited by glucose
2 baseline GH levels after fasting for 8 hours
Ingestion of 75g of oral glucose
GH measurement at 30, 60, 90, 120mins post oral glucose load
Active acromegaly
Di cause tests
Pituitary Anatomy
MRI pituitary: show micro or macro adenoma
CT scan: thorax, abdomen, pelvis
Non-endocrine tumours / ectopic GH secretion
Screening complications
Anterior pituitary function tests:
Decreased Serum TSH ACTH and Cortisol
Reduced Serum LHRH, LH, FSH, testosterone
Raised Serum prolactin
ECG . BP, CXR - heart failure signs cardiomegaly
Sleep studies (sleep apnea)
CoLONSCOPY
DM - screen
dx test chushings
Random cortisol (not helpful usually as peaks & troughs throughout day & varies due to stress, illness,etc)
24 hour urinary free cortisol: HIGH
Midnight cortisol- high
Overnight dexamethasone suppression test
- 1mg dexamethasone at midnight
do cortisol level at 8am - normal should decrease if not low then CS
24 hour dexamethasone suppression test
Screening for cushing cause
Where is the lesion?
Plasma ACTH: If undetectable- likely adrenal cause → CT adrenal
Plasma ACTH: if detectable-
Do corticotrophin releasing test
Cortisol rises - pituitary cause – > BRAIN MRI then inferior petrosal sinus sample
ectopic ACTH does’t else
riASeD BP and hypokalemia
Primary hypoaldosteronism
treatment Conns
Treat underlying cause
Hypokalaemia: IV potassium replacement via slow infusion
Conn’s syndrome:
Laparoscopic adrenalectomy
Spironolactone for 4 weeks pre-op for BP & K+ control
Hyperplasia
Treat medically with aldosterone antagonists e.g. spironolactone, eplerenone, amiloride
Complications & prognosis
Depends on the cause
lab for primary vs secondary hyperaldosteronism
primary - low RAS, high aldosterone
secondary - low renal perfusion so HIGH renin
short synacten test
Do plasma cortisol beofre & 30 mins after giving tetracosactide
(Synacthen 250 μg) IM
Addison’s is excluded if 30minute cortisol is >550nmol/L
( steroid drugs may interfer with this assay)
Synacthen = ACTH
hyponatremia symptoms
Na <135 Brain - headache, confusion Falls, coma,deep somnolence and seizure Cardioresp distress N V anorexia
hyponatremia screening for cause
- U&E
- Serum & urine osmolality
- Urinary sodium
- glucose (High sugar - pseudohyponatraemia (add approx. 4.3mmol/L to plasma Na + for every 10mmol/l rise in glucose above normal)
isotonic hyponatremia
hyperproteinemia
Hyperlipidemia
Hypertonic hypoglcyemia
hyperglycaemia
mannitol, orbital, glycerol, maltase
radiocontrast agents
isotonic - serum osmolarity - 280-295 mosm/kg
hypotonic hypovolemic hyponatremia
UNa<10
- dehydration
- diarrhea
- vomitting
UNa > 20 (reduced salt loses) - Diuretics - ACE inhibitors - Nephropathesis - Mineralocorticoids deficiency - cerebral sodium wasting syndrome
hypotonic euvolemic hyponatremia
- SIADH
- Post op hyponatremia
- Hypothyroidism
- Psychogenic polydipsia
- Beer potornania
- Drugs - diuretics, thiazide, ace -
- Edurance exercise
- adrenocorticotropin deficiency
hypotonic hypervolemia hyponatremia
OEDEMATOUS STATES
- CCF
- liver disease
- Nephrotic syndrome
- Advanced kidney disease
correction hyponatremia
hypervolemia or euvolemic - fluid restrict, water intake < 1.5
hypovolemic - give them normal saline or RINGERS
with hyponatraemia with moderate &severe symptoms, 3% saline( usually 150mls
How to correct low Na
- Na+ at 0.5mmol / h
Not more than 12 -16 h or 0.5 - 1.0mmol per hour
Correct slowly to prevent osmotic demyelination
Hypernatremia vulnerable groups
elderly
confused,
children
unconscious
screen for cause HYPERNATREMIA
Serum osmolality ( hyperosmolar in hypernatraemia)
Urine osmolality
Low: often have Diabetes insipidus - see DI lecture
High: unreplaced GI, renal, or insensible losses or osmotic diuresis
Check glucose (to look for uncontrolled diabetes as a cause)
Urinary sodium
Serum and urine osmolarity in DI and SIADH
DI
- low urine osmolality (can’t concentrate urine - therefore low solutes in urine)
- High serum osmolality
SIADH
- high urine osmolality
- low serum osmolality
treatment of hypernatremia
h2O orally
- give IV fluids slowly to prevent cerebral oedema
Ecg HYPERKALEMIA
all tented T waves, small p waves,
widened QRS- eventually becoming sinusoidal &
leading to ventricular fibrillation
Treatment HyperKalemia - URGENT (K>6)
10ml calcium gluconate IV (
Insulin- dextrose e.g. 5-10 units actrapid in 50mls of 50% Dextrose IV
Nebulised salbutamol 2.5-5mg neb stat
Patients in renal failure with hyperkalaemia - dialysis
Non urget Treatment HyperKalemia
find the cause
- Polystrene sulfonate resin (e.g. Calcium reosnium 15 g/ po tds) can be used as it binds K+ in the gut , bringing down K+ levels over a few days.
Causes of HYPOKALEMIA
Vomiting/ nasogastric suction
Diarrhoea
Intestinal fistula
Ileostomy
Rectal villous adenoma
Renal tubular failure/ other renal losses
Medications e.g. Diuretic therapy, salbutamol
Cushing’s syndrome/ Conn’s syndrome
Alkalosis
Bowel cleansing pre-colonoscopy preparations/ laxatives
Osmotic diuresis
Clinical Hypokalemia
Usually asymptomatic Muscle weakness Hypotonia Hyporeflexia Cramps Tetany Palpitations Light-headedness (arrhythmia)
Complication of hypokalemia
Arrhythmia
paralysis
rhabdomyolysis
diaphragmatic weakness
ECG hypokalemia
U wAVE decreased T waves ST segment depression PR interval prolongation QRS prolongation
TREATMENT hypokalemia
MILD-MOD
10-20kcl ORAL given 2-4 times a day
SEVERE
IV 20-40 KCL in 1 L of normal saline over 6-8 hours
Max rate of infusion for K+
10-20 mmol/h
hypomagnesium cause
Severe diarrhoea Alcohol misuse Diuretics Total parenteral nutrition Renal tubular acidosis Malabsorption/ malnutrition Diabetic ketoacidosis
if you correct K too fast what can happen
Cardiac arrest
treatment hypomagnesium
Mil - oral Mg
Severe - IV Mg sulfate in a solution of normal saline or dextrose
Clinical hypomagnesium
Asymptomatic Paraesthesia Ataxia Seizures Arrhythmias Tremor Tetany
treatment of hypercalemia
IV saline administration (watch for fluid overload)
Bisphosphonates (inhibit osteoclasts e.g. IV zolendronic acid
SE: Flu like illness, osteonecrosis of jaw, bone pain, hypocalcaemia)
Calcitonin
Steroids: used in hypercalcaemia associated with sarcoidosis
treatment of hypercalcemia
Mild - ORAL vit D and calcium
- if no response on oral switch to UV
Severe- 10ml of 10% calcium glucoronate
Correct Mg if low
what type of calcium do you use in CKD
Calcitriol (this is the active form and therefore prevents the kidney from activating it
hypoglycaemia definition
low blood surgery when level drops < 3.9 mmol/L It consistent Whipple's train - symptoms consistent hypoglycaemia measurement low plasma glucose relief of symptoms after plasma glucose
Treatment
15-20mg fast acting carb
- dextrose, lucosade(100mls), sweetened fruit juice
- glucotabs - 4g each so 4-5 chewable ones
If severe with coma or confusion
- At home - IM glucagon 1mg
- Inhospital - 50% dextrose 50mls IV
200-300 of 10% dextrose IV
2 dynamic function test for evaluating HYPOpituitarism
Growth hormone deficiency testing:
1) Insulin induced hypoglycaemia test- risk of seizures/ angina/ hypoglycaemia/adrenal crisis.
2) Arginine & growth hormone releasing hormone test
ACTH deficiency testing:
1) Short synacthen test to assess adrenal axis
2) Cosyntropin/ rapid ACTH stimulation test
pheochromocytoma 10% rule
10% are malignant
10% are extra- adrenal
10% bilateral
10% familial
MEBF
biochemical test for phaeochormocytoma
24hour urinary testing VMA, catecholamines or metenephrines ( most sensitive)
- repeat urinary testing x 3 (episodic)
Plasma catecholamines & metenephrines
Images for phaeochormocytoma
MRI ( T2 weighted ) with gadolinium contrast
CT with contrast
Nuclear imaging with radioactive tracer can also be used e.g PET, MIBG scan
subclinical hypothryodisim
TSH mildly increase , T3 and T4 normal
ONLY TX
Reasons to treat
1. Risk to become clinical
- previous Graves/ autoimmune
- positive thyroid antibody
- goitre
2. Hyperlipidaemia
3. atherosclerosis
4. Pregnancy or trying
5. Reduce quality of life if symptomatic
6. TSH >10acute thyroiditis
HIGH ESR
TENDER THYROID
Most common cause of hypothyroidism and how to distinguish
Hashimotos thyroidisim
- HIGH ANTIBODIES TITERS
anti-thyroids peroxidase antibodies (anti TPO)
anti-thyroidgnobulin antibodies
treatment hypothyroidism
Start 50-100 mcg per day
increase 25-50mcg in increments by 4-6 weeks until TSH stable
ONCE stable monitor in 6-12 months
treatment of hypothyroidism in elderly and ischemic heart disease
Caution in
Start at 25micrograms daily & adjust slowly in 4 weekly increments of 25 micrograms ( risk of precipitating angina or myocardial infarction)
Drug that interfere with absorption
with thyroxine absorption
AFFECTS ABSORPTION
Antacids (aluminum containing)
Iron tables
Calcium tablets
INCREASES METABLOSIM
- anti-epileptic
- Rifampin
complication of hypothyroidism
Myxoedema coma Ischaemic heart disease Weight gain/ obesity Rare neurologic problems include reversible cerebellar ataxia, dementia, psychosis, and myxedema coma. Hashimoto's encephalopathy
important additional test to get any female elderly with hypothyroidism
- DEXA
risk factors and pathogenesis for thyroid eye disease and findings
SMOKING
- exopthalmous
- ptosis
- conjunctival edema
- ophthalmoplegia
- papillodema
- loss of colour vision
RETRO - orbital inflammation and lymphocyte inflammation results in swelling of orbit
Jod Basedow presentation
hyperthyroidism following administration of iodine
causes of hyperthyroidism
Graves’ disease ( 60-80% of cases) Toxic multi-nodular goitre Solitary toxic thyroid nodule Thyroiditis (Hashimoto’s; deQuervains) Post-partum thyroiditis Ectopic thyroid tissue eg. metastatic follicular thyroid cancer, struma ovarii Medications eg amiodarone, l-thyroxine excess Jod-Basedow phenomenon
pretibial myexedema and exophthalmus in hyperthryoidism
DUE to TSH receptor - fibroblast behind the eye and skin have TSH receptors therefore glycoamminoglycans “DOUGH like apperenace”
antibody in hyperthyroidism
TSH receptor antibodies (graves) antithyroid peroxidase (autoimmune)
Treatment of Graves
- Beta blockers - symptoms
- Carbimazole or Propylthiouracil (PTU)
- Radio-iodine
- Surgery
- obstructive goitre
- contraindication to RAI
what precaution do u have to tell patients who start Carbimazole
STOP medication if they get a sore throat or mouth ulcers
- b.c can can agranulocytosis
treatment for thyroiditis
Analgesia- NSAIDS Beta-blockers Steroids (taper over 2 weeks) L- thyroxine --> if become hypothyroid Monitor TFT’s closely- every 2-4 weeks until normalise
reason to treat subclinical hyperthyroidism
Atrial fibrillation Osteoporosis Increased cardiovascular disease risk Progression to clinical hyperthyroidism Multi nodular Goitre
complications of hyperthyroidism
Atrial fibrillation Heart failure Angina Osteoporosis Ophthlamopathy Oligomenorrhoea/ amenorrhoea Gynaecomastia
success rate of RAI
10-205 FAIL frist time and require a 2nd dose
Dx of T1DM
Fasting Plasma Glucose > 7.0 mmol/l ⃰ Fasting is defined as no caloric intake for at least 8 hours
Plasma glucose > 11.1 mmol/l two hours following Oral Glucose Tolerance Test. (OGTT) ⃰
Random plasma glucose >11.1 mmol/l ( in symptomatic patient)
HBA1C > 48 mmol/mol. ( >6.5%) ⃰
antibodies in islet cell
AntiGAD
isle cell antibody
blood target levels for t1DM
FBG: 5-7 mmol/litre
PG: 4-7 mmol/litre before meals
PG: 5-9 mmol/litre at least 90 minutes after eating
HbA1C: <6.5%
patient suffering from depression constipation and a pain in his back
think hypercalemia
- measure serum Calcium levels
22 year old complains of dizziness and feeling light headed when she stands up to go to the toilet , she noticed her scar is much darker
THINK ADDISONS disease
- SYNACTHEN TEST
you inject synacthen (ACTH) and you would expect their to be an increase cortisol
