Endocrinology Flashcards
How do you determine between Grave’s and De Quervain’s Thyroiditis?
Both are hyperthyroidism presenting with a goitre
Grave’s - non tender goitre
De Quervain’s - painful goitre
Why is exophthalmos specific to Grave’s Disease?
It is a consequence of TPO antibody infiltration and oedema of the periorbital tissues and muscles
Why is the majority of the Hydrocortisone and Fludrocortisone dose given in the earlier half of the day?
Steroids can cause insomnia
What are the biochemical features of Addisonian Crisis?
Hypernatraemia
Hypokalaemia
Hypoglycaemia
PMHx - of using steroids and stopping
What are the causes of raised prolactin levels?
Prolactinoma
Medications
Non-functioning pituitary adenoma
Pregnancy
What is the first line test for diagnosing Cushing’s Syndrome?
Low- dose dexamethasone suppression dose
High-dose helps distinguish the causes
What are the causes of primary adrenal insufficiency? ( Low cortisol, high ACTH)
Addison’s DIsease ( autoimmune )
Infections - TB, fungal, secondary infections to HIV
Infiltration - Amyloidosis, Sarcoidosis
Adrenal Tumours - primary and metastatic
What is Waterhouse-Friderichsen syndrome?
A complication of meningococcal infection, it is adrenal insufficiency secondary to bilateral adrenal haemorrhage
How does a pituitary adenoma cause hypopituitarism?
The compress the normal gland tissue causing it to cease functioning properly
What is the first line test for diagnosing Pheochromocytoma ?
24 hour Urinary metanephrines ( 1st ) and catecholamines
Plasma metanephrines are more specific
How does Carbimazole work?
Decreases the uptake and concentration of iodine by the thyroid. It also prevents the thyroid peroxidase enzyme (TPO) from coupling and iodinating the tyrosine residues on thyroglobulin
What is the first line test for Addison’s Disease?
9am serum cortisol ( low cortisol warrants further investigation)
Then do short SynCATHen test (cortisol levels don’t rise in response to exogenous ACTH)
Confirms primary adrenal insufficiency
Which drugs can cause thyrotoxicosis (high T4) ?
Amiodarone
Can stimulate or damage the thyroid gland ( similar to iodine )
What drugs can cause hypothyroidism?
Amiodarone
Lithium
What are pituitary tumours best visualised on?
Brain MRI
What is the gold standard investigation to clarify a diagnosis of hypopituitarism?
Insulin tolerance test
The stimulates hypoglycaemia, so it can test both ACTH and GH production , these would both increase in normal people eith hypoglycaemia
What are the most common types of thryoid cancer?
Young females - Papillary Thyroid Cancer ( popular)
Elderly female - Thyroid lymphoma ( long life )
How does PTH increase bone ressorbtion?
Binds to osteoblasts, which stimulate osteoclasts via paracrine signalling
What is included in MEN1?
pituitary tumours
parathyroid hyperplasia
pancreatic tumours
What is the first-line management for toxic adenoma or toxic multinodular goitre?
Radioiodine therapy
What is the treatment for patients with an Addisonian Crisis?
FLuid resuscitation
IV Hydrocortisone
How do they Dexamethasone suppression tests work?
Low dose - given at night time. In morning, early morning cortisol levels are not suppressed.
High dose - this will cause suppression of ACTH production by the pituitary adenoma in Cushing’s Disease. However, in ectopic production of ACTH, the cortisol will still not be suppressed as it does not work via a negative feedback cycle.
What is the first line test for suspected Primary Hyperaldosteronism?
Aldosterone/renin ratio ( Aldosterone will be high )
Then to differentiate between causes, a CT of the adrenal glands
Gold standard - s elective adrenal venous sampling can be used ( This shows if its bilateral adrenal hyperplasia because both the left and right adrenal veins will have high aldosterone)
What are the physiological levels of T3, T4 and TSH in the 2nd and 3rd trimester?
T3 and T4 low
TSH normal
What heart problems is hyperthyroidism associated with?
Tachycardia
Atrial FIbrillation
What is the treatment for DKA?
Initially give I.V NaCl Fluid bolus
Give fixed rate insulin infusion an hour later at 0.1 units/kg/hour
What is the treatment for Type 1 Diabetes if the patient becomes hypoglycaemic or hyperglycaemic?
In the community
Hypoglycaemic -
-Consume 15-20g of fast-acting carbohydrate (e.g., glucose tablets, non-diet soda, sweets, fruit juice)
-If patient can’t tolerate oral then do IM Glucagon injection
If in hospital and severe ( seizures, hospital) - Administer 200ml 10% dextrose IV
What are the clinical features of Klinefelter’s?
Delayed puberty
Gynecomastia
Microorchidism
Poor coordination
Muscle weakness
What is the first line treatment for type 1 diabetes?
Basal-Bolus insulin regime
Long acting insulin at night ( e.g Determir )
Short acting insulin 30 minutes before a meal ( e.g Novorapid)
What hormone is most commonly secreted by a Carcinoid Tumour?
Serotonin ( 5HT3)
What is the first line investigation for Acromegaly?
Serum IGF-1 = first line
Then do Oral Glucose Tolerance test to confirm
Give patient oral glucose and GH is not supressed
What is the treatment for Acromegaly?
Transphenoidal resection of pituitary adenoma
Octreotide ( Somatostatin Analogue) if remission is failed with surgery
What is MEN1 associated with?
Parathyroid hyperplasia/adenomas
Pancreatic tumours (gastrinomas, insulinomas)
Prolactinomas.
What is MEN2a associated with?
Medullary thyroid cancer
Pheochromocytoma
Parathyroid hyperplasia/adenoma.
What is MEN2b associated with?
Medullary thyroid cancer
Pheochromocytoma
Parathyroid hyperplasia/adenoma
Mucosal neuromas
What is a complication of treating DKA?
Cebrebral Oedema
What drugs are first line for diabetic neuropathy?
Pregabalin, Duloxetine, and Gabapentin
How do you work out basal-bolus amounts?
basal bolus as 0.5units x weight = 24 hour requirement
then in 24 hours; 50% = basal and 50% = bolus.
the 50% bolus = split in 3 meals
If 100kg - 0.5x100 = 50units needed in 24 hours
Basal = 12 units , bolus = 12/3 = 4 units
What is the add on to Metformin recommended if you have cardiovascular disease or have a new diagnosis of CVS problems during treatment for diabetes?
SGLT2 inhibitor
If a patient has a HbA1c > 48mmol/L can you diagnose Diabetes?
Only if they are symptomatic, otherwise a confirmatory blood glucose sample should be arranged
How is the dose of Hydrocortisone given in Addison’s disease?
Majority given in the first half of day and rest given in second half of day
Trying to recreate circadian levels of cortisol
What is a myxoedema storm?
Myxoedema coma is a potentially fatal complication of longstanding undertreated hypothyroidism. It may be precipitated by illness, stress, and certain drugs. Apart from confusion and hypothermia, patients may have non-pitting periorbital and leg oedema, reduced respiratory drive, pericardial effusions, anaemia, seizures, and other symptoms of hypothyroidism.
What is Pre-diabetes HbA1c?
42-47mmol/L
What is the maximum dose of Metformin?
2g/day usually given as 1g b.d
What are the side effects of Metformin?
What are the side effects of Sulphonylureas?
What are the side effects of SGLT-2 inhibitors?
UTIs/genital infection
normoglycemic ketoacidosis
increased risk of lower-limb amputation ( check feet)
What is the type 1 diabetic sick day rules?
Stay on normal routine
Check blood sugars more frequently
What can make the HbA1c look lower than expected?
Sickle-cell anaemia
GP6D deficiency
Hereditary spherocytosis
Haemodialysis
Due do decreased RBC lifespan
What can make the HbA1c look higher than expected?
Vitamin B12/folic acid deficiency
Iron-deficiency anaemia
Splenectomy
Due to increased RBC life span
What is the treatment for DKA?
500ml blus 0.9% saline
FRII ( Actrapid ) 0.1unit/kg/hour
What is a complication of DKA ?
Cerebral Oedema
What is the primary investigation for diagnosing DMT1?
Serum glucose
fasting glucose, random glucose or oral glucose tolerance test
What are the thresholds for diagnosis of DMT1?
If symptomatic
Random blood glucose ≥ 11.1mmol/l or Fasting plasma glucose ≥ 7mmol/l
2-hour glucose tolerance ≥ 11.1mmol/l
HbA1C ≥ 48mmol/mol (6.5%)
How should normal insulin regimes be adjusted if a patient is going on a FRII?
Stop short-acting insulins
Stay on long acting insulins
What conditions are associated with Type 1 Diabetes?
Thyroid conditions
Coeliac’s Disease
What are the initial investigations for DKA?
CBG - acidosis, low bicarb
Blood ketones >3
Blood glucose >11.1
U&Es - hypokalaemia
How is basal-bolus insulin worked out?
Total insulin units per day
2/5 = basal long term
3/5 = short term, split into 3 meals
What is the VBG finding in DKA?
Metabolic Acidosis with a raised ion gap
What are some symptoms of diabetic retinopathy?
Floaters or dark spots in the vision
Blurred or distorted vision
Difficulty seeing at night
Sudden loss of vision
What will be found on examination with mild retinopathy?
Microaneurysms
Hard exudates
Blot haemorrhages
Neo-vascularistaion
What will be found on examination in severe diabetic retinopathy?
Cotton wool spots
Large blot haemorrhages
Which diabetes drug is mainly associated with hypos?
Sulphonylureas e.g Gliclazide
Is target BP different for people with Diabetes?
No
What is the cause of peripheral neuropathy?
Microvascular
Advanced glycation end product effects on matrix metalloproteinases, this damages nerves
What bacteria is commonly found in diabetic foot ulcer?
Pseudomonas aeruginosa
What is the treatment for a diabetic foot ulcer?
Debridement
Use dressings while ulcer heals
Oral Flucloxacillin and Gentamicin ( Pseudomonas)
What are some hallmarks of peripheral neuropathy?
Numbness
Anhidrosis
Accumulation of trauma without patient realising
What antihyperglycemics would be stopped in end of life care?
Insulin
Gliclazide
Due to the risk of hypos, will affect quality of life
When is HbA1c inaccurate?
Haemolytic anaemia
CKD
Chronic liver disease
Haemoglobinopathies
Steroids
Why might a HbA1c be higher than expected?
Prolonged lifespan of RBCs
Splenectomy
Iron-deficiency anemia
Vitamin B12/Folic acid deficiency
What might make the HbA1c lower than expected?
Due to reduced red blood cell lifespan
Sickle-cell anaemia
GP6D deficiency
Hereditary spherocytosis
Haemodialysis
What does Cortisol do to blood sugar levels?
Stimulates gluconeogenesis
Promotes glycogenolysis
Reduces glucose uptake by tissues
Increases blood sugar ( Stress, repair, fight or flight respons)
What is the treatment for DKA?
1L 0.9% Saline over 1 hour
FRII 0.1units/kg/hour
Correct any hypokalemia that make occur
What is the treatment for a thyrotoxic storm?
Beta blockers, propylthiouracil and hydrocortisone
