Endo Flashcards
Signs / Symptoms of DMT2
Polyuria
Polydipsia
Polyphagia
Glycosuria
Usually picked up on routine blood tests
Pathology of DMT2
Repeated, prolonged exposure to glucose results in insulin resistance
+
Pancreatic B cells become damaged from hyperglycaemia and produce less insulin
=
Chronic hyperglycaemia
Ix DMT2
-
HbA1C - GS !!
tells us avg. blood glucose levels for past 3 months
HbA1C > 48 mmol/L = DIABETES
HbA1C between 42 - 47 mmol/L = PRE-DIABETES
- Blood tests
Random plasma glucose > 11.1 mmol/L
Fasting plasma glucose > 7 mmol/L - Oral glucose tolerance test
Fasting > 7 mmol/L
then test 2 hours after glucose
//
If asymptomatic, at least 2 of above
If symptomatic, 1 of above
Tx T2DM
1st line - Lifestyle management
2nd line - Metformin
3rd line - if HbA1C rises to 58, depends on drug tolerance/individual factors
Metformin + sulphonylurea e.g. glicazide
Metformin + DPP4-inhibitor e.g. sitagliptin
Metformin + SGLT-2i e.g. glifazon
4th line - Insulin
Mechanism of Sulphonylurea
Stimulates pancreatic B cells to secrete insulin
S/E of sulphonylurea
Weight gain
Hyponatraemia
Hypoglycaemia
Examples of sulphonylurea
Glicazide
Glimepiride
Describe the mechanism of Metformin
Increases insulin sensitivity
Decreases hepatic gluconeogenesis
Side effects of Metformin
When is it CI?
GI upset
Lactic acidosis
CANNOT be used in Px with eGFR < 30ml/min AKA renal failure!!
Describe the mechanism of DPP4-inhibitors
Increase incretin levels
∴ ↓ Glucagon secretion
Side effects of DPP4-i
Usually not many side effects
But does increase risk of pancreatitis
Describe the mechanism of SGLT-2 inhibitors
Inhibits reabsorption of glucose in the kidney
Side effects of SGLT-2 inhibitors
UTI !!
& Weight loss
Example of SGLT-2 inhibitors
Glifazone
Example of DPP4-i
Sitagliptin
Signs / Symptoms of Cushing’s
Round, moon face
Truncal obesity
Abdominal striae
Buffalo hump
Acne
Hirsutism
Mood changes - depression, anxiety
Irregular periods - Amennorhoea
Proximal limb wasting
Define Cushing’s
Chronic, abnormal elevation of cortisol
Causes of Cushing’s
ACTH-Independent -
> Iatrogenic !! - most common!
usually prednisolone (or other steroids)
> Adrenal adenoma - benign tumour, secretes XS cortisol
ACTH-Dependent
> Cushing’s disease - Ant. pituitary adenoma causes ↑ ACTH ∴ ↑ cortisol
(most common dependent cause)
> Ectopic ACTH production - neoplasm somewhere in body, esp small cell lung cancer!! also carcinoid tumours - produce XS ACTH
Investigations for Cushing’s
1st Line - Raised plasma cortisol
(don’t do randomly! bc cortisol levels fluctuate throughout the day)
GS!! DEXAMETHASONE SUPPRESSION TEST - low dose (1mg)
Other -
24hr urinary free cortisol (can be used instead of ^DST but doesn’t indicate cause)
MRI brain - to find pituitary adenoma
Chest CT - SCLC
Abdo CT - adrenal tumours
Describe how you can identify the cause of Cushing’s disease using the dexamethasone suppression test
Low dose (1mg) should be suppressed to < 50 nmol after 2 hours if normal
If NOT suppressed = Cushing’s syndrome
THEN high dose,
If Cushing’s disease, Px should suppress within 48 hours.
If NOT, it suggests an ectopic source (high ACTH) or adrenal tumour (low ACTH).
Treatment for Cushing’s
If iatrogenic, STOP STEROIDS !!
If adrenal adenoma, adrenalectomy
If Cushing’s disease, transsphenoidal surgery to remove pituitary adenoma
If ectopic ACTH production and hasn’t metastasised, surgery to remove neoplasm
If can’t do surgery, could remove both adrenal glands and give replacement steroid hormones for life
CUSHING
(acronym)
Cataracts
Ulcers
Striae
Hyperglycaemia or HTN
Increased risk of infection
Necrosis
Glycosuria
RF Acromegaly
MEN-1
Why are plasma GH levels not used as a diagnostic factor in Acromegaly?
Bc secretion is pulsatile
increases due to stress, pregnancy, puberty and during sleep
Signs / Symptoms Acromegaly
Bitemporal hemianopia
Large, spade-like hands and feet
Frontal bossing
Large ears, tongue, nose
Spacing between teeth
Large protruding jaw
Back ache
Arthralgia
XS sweating
Sleep apnoea
Amenorrhoea
Oily skin
Mood disturbances
Headache
Acroparaesthesia / Carpal tunnel signs
“My rings don’t fit anymore, I’ve gone up a couple of shoe sizes recently and my teeth have become more separated”
Pathophysiology of Acromegaly
Hypothalamus secretes GHRH ∴ Ant. pit secretes GH
XS GH causes XS production of IGF-1
∴ inappropriate growth of soft tissue and bone
RF Acromegaly
MEN-1
Ix Acromegaly
1st Line - Raised IGF-1 (bloods)
GS !! - Oral glucose tolerance test !
Give Px glucose
Serum GH should fall if normal
In acromegaly, serum GH release is not suppressed
Tx Acromegaly
If Acromegaly secondary to pit. adenoma, do transsphenoidal surgery to remove
If secondary to cancer, surgically remove tumour
–
If can’t do above, can be treated w/ mediation :
1. Somatostatin analogues e.g. octreotide - blocks GH release
2. Pegvisomant - GH antagonist given via SC daily
3. Dopamine agonist e.g. cabergoline, bromocriptine - blocks GH release
S/E of Somatostatin analogues
Pain at injection site
Loose stool
Abdo cramps
↑ Gallstones
Impaired glucose tolerance
When would you use pegvisomant instead of somatostain analogues (SSA) ?
If intolerant or resistant to SSA
Monitoring Acromegaly
Yearly follow up - vascular assessment, visual fields, GH levels, BMI
Complications / Co-morbidities Acromegaly
HTN / Heart disease - due to ↑ GH ∴ hypertrophy of the heart
Sleep apnoea
Arthritis - due to overgrowth of cartilage
T2 Diabetes - bc constantly high blood glucose
Carpal tunnel - muscle growth compresses nerve
Visual field defects - bitemporal hemianopia
Cerebrovascular events + headaches
RF Prolactinoma
Female
Peak incidence @ 20 - 40 years
Signs / Symptoms Prolactinoma
GENERAL : Headache, visual defect (bitemporal hemianopia), CSF leak (rareee)
FEMALES : Amennorrhoea, oligomenorrhoea, infertility, low libido, galactorrhoea
MALES : Erectile dysfunction, low testosterone, ↓ facial hair, low libido
–
Males can have galactorrhoea too but rarer
Pathophysiology Prolactinoma
Tumour of lactotroph cells
∴ hypersecretion of prolactin
∴ inhibits release of GnRH from hypothalamus
∴ ↓ LH, FSH from ant. pituitary
↓ release oestrogen and progesterone in females / in males ↓ release of testosterone
–
2° hypogonadism
Ix Prolactinoma
1st Line - Serum prolactin levels (ALSO GS!!! If high = prolactinoma)
2nd Line - Pituitary MRI (to detect adenoma)
Tx Prolactinoma
Medication is preferred over surgery!
1st Line - Dopamine agonists
e.g. ORAL cabergoline, bromocriptine
(bc dopamine inhibits prolactin secretion ∴ shrinks the prolactinoma)
Usually see big reduction of macroadenoma, can be sight saving
Microadenoma - responds to small doses, 1 or 2 a week
2nd Line - Hormone replacement therapy e.g. oestrogen
(if galactorrhoea/fertility isn’t an issue)
Complications Prolactinoma
Infertility
Sight loss
↑ Intracranial pressure - bc adenoma growth
Quick! What is Addison’s?
Too little cortisol and too little aldosterone
What is the fun key phrase to remember for Addison’s?
Tanned, Toned (fit and ready), Tired, Tearful
Causes of Adrenal Insufficiency
1° - Addison’s aka autoimmune adrenalitis (most common! 90%!)
Adrenal TB
Surgical removal of adrenal glands
Adrenal infarction/haemorrhage (meningococcal septicaemia)
Malignancy
2° - Steroids
CRH deficiency
Trauma
Radiotherapy
Signs / Symptoms Adrenal insufficiency
N + V
Fatigue
Postural hypotension
Hyperpigmentation esp in palmar creases for Addison’s
Pallor
Headaches
Depression
Impotence
Amennorrhoea
Weight loss
REMEMBER : Tanned, Toned, Tired, Tearful
Ix Adrenal Insufficiency
> GS!! Short synACTHen
If Px healthy, cortisol levels should double
If doesn’t, indicates Addison’s (1°) (or doesn’t indicate between 1° and 2° confused)
> Plasma ACTH levels
If high with low/normal cortisol = 1° (Addison’s)
If low with low cortisol, indicates 2° or 3°
> U&E
Low Na+ and High K+ (bc low aldosterone)
Low aldosterone, high renin
Tx Adrenal Insufficiency / Addison’s
STEROIDS!! - double dose if trauma, nightshift work, infection or surgery
Oral Hydrocortisone/Prednisolone - to replace cortisol
Fludrocortisone - to replace aldosterone
Which medication used to treat adrenal insufficiency corrects postural hypotension?
Fludrocortisone
Bc by replacing aldosterone, it ↑ Na+ and ↓ K+
What is an Addisonian crisis?
Medical emergency!! Sudden drop in aldosterone and cortisol
How does an Addisonian crisis present?
Hypotension and cardiovascular collapse
Fever
Hypoglycaemia
Hyponatraemia and hyperkalaemia
Hypovolaemic shock
Confusion
Fatigue
N+V
Abdo and back pain
Muscle cramps
How to treat an Addisonian crisis?
Fluid and IV Hydrocortisone
Describe the differences between 1°, 2° and 3° adrenal insufficiency
1° - adrenal gland is damaged (Addison’s)
∴ ↓ cortisol and ↓ aldosterone
Most common cause worldwide = TB, in UK = autoimmune adrenalitis
2° - loss/damage of pituitary gland
∴ inadequate ACTH (∴ less stimulation of adrenal gland)
3° - suppression of hypothalamus
∴ inadequate CRH release
Usually bc patients on long term oral steroids (more than 3 weeks)
When treating adrenal insufficiency, what is important to remember?
Double dose of steroids if infection, trauma, surgery or nightshift work
Causes Hyperthyroidism
GRAVES’ DISEASE (80%!!)
Toxic multinodular goitre
XS iodine consumption
De Quervain’s thyroiditis/Thyroiditis
Drug induced (iodine, amiodarone)
Pregnancy
Signs / Symptoms Hyperthyroidism
General :
Weight loss
Heat intolerance
Palpitations
Anxiety
Tremors
Tachycardia
Graves’ Specific :
EYE SIGNS! - Exopthalmos, lid retraction, lid lag, lacrimation, diplopia
Pretibial myxoedema
Thyroid acropachy
Diffuse goitre
Ix Hyperthyroidism
- THYROID FUNCTION TEST
If 1° - ↓ TSH, ↑ T3/T4
If 2° - ↑ TSH, ↑ T3/T4 - THYROID AUTO-ANTIBODIES
Thyroid peroxidase Abs - more in hypothyroidism
Thyroglobulin Abs
TSH receptor Abs (TRAb) - ONLY Graves - THYROID ULTRASOUND
- RADIOACTIVE ISOTOPE UPTAKE SCAN
Much higher in Graves’
Important !
If drug induced, everything is normal except ↑Thyroid hormones
–
Might be mild normocytic anaemia and mild neutropenia
Tx Hyperthyroidism
Depends on cause !
> Beta blockers - rapid system control in attacks
> Anti-thyroid drugs e.g. Carbimazole - blocks thyroid hormone synthesis
> Radioiodine treatment
nb. can do thyroidectomy but leave a small bit behind so thyroid function can still happen
What is a common S/E of Carbimazole when treating Hyperthyroidism?
Agranulocytosis
Contraindications of Radioiodine treatment in Hyperthyroidism
Pregnancy
Breast-feeding
Mechanisms for Hyperthyroidism
- Overproduction of thyroid hormone
- Leakage of pre-formed hormone from thyroid
- Ingestion of XS thyroid hormone
What are the 2 strategies when giving Carbimazole for hyperthyroidism?
- Titration - oral carbimazole for 4 weeks then reduce according to TFTs
- Block & Replace - oral Carbimazole and thyroxine (has a less risk of going hypo)
Complications of Hyperthyroidism
Congestive HF
Atrial Fibrillation
Osteoporosis
Graves’ opthalmopathy complications
Graves’ dermopathy - elephantitis
THYROID STORM
Comp of Radioiodine therapy when treating Hyperthyroidism
Could lead to HYPOthyroidism
Mechanism of Radioiodine therapy when treating Hyperthyroidism
Iodine taken up and local irradiation and tissue damage causes return to normal
function
What drugs must be adjusted alongside a thyroidectomy when treating hyperthyroidism?
Anti-thyroid drugs are stopped 10-14 days prior and replaced w/ oral potassium iodide
Complications of Thyroidectomy
Bleeding
Post-op infection
Hypocalcaemia
Hypothyroidism
Hypoparathyroidism
Recurrent laryngeal palsy - due to laceration
Recurrent hyperthyroidism
What is Thyroid Storm / Thyroid Crisis?
Rare, life-threatening condition
Rapid deterioration of thyrotoxicosis
Signs / Symptoms Thyroid Storm
Hyperpyrexia
Tachycardia
Extreme restlessness
Potentially delirium, coma and death
What is Thyroid Storm usually precipitated by?
Infection
Stress
Surgery
Radioactive Iodine therapy
How do you treat Thyroid Crisis/Thyroid Storm?
Large doses of Carbimazole
Propanolol
Potassium iodide - to acutely block release of thyroid hormone from gland
Hydrocortisone - inhibits peripheral conversion of T4 to T3
Causes Hypothyroidism
Post-partum
Autoimmune thyroiditis (Hashimoto;s)
Iodine deficiency
Drug-induced (Carbimazole, Lithium, interferon Amiodarone)
Iatrogenic (thyroidectomy or radioactive iodine therapy)
Congenital hypothyroidism
Signs / Symptoms Hypothyroidism
Symptoms :
Goitre
Weight Gain
Constipation
Lethargy
Poor memory
Puffy eyes
Arthralgia
Hoarse voice
Cold intolerance
Menorrhagia
Tiredness
Signs : BRADYCARDIC
Bradycardic
Reflexes relax slowly
Ataxia
Dry thin hair/skin
Yawning
Cold hands
Ascites
Round puffy face
Defeated demeanour
Immobile - ileus
Congestive HF
–
nB . Women w/ period problems should always have hypothyroidism excluded !!
Ix Hypothyroidism
Thyroid Function Tests
1° - ↑ TSH, ↓ T3/4
2° - ↓↓ TSH (inappropriately low for what T3/4 are), ↓ T3/T4
Thyroid Antibodies
Anti-thyroid Peroxidase Abs in Hashimoto’s!!!!
Other Hypo
> FBC - normocytic, normochromic anaemia. Could be macrocytic (menorrhagia) or microcytic (pernicous anaemia)
> Hyperlipidaemia
> Hyponatraemia (bc ↑ ADH)
> ↑ Serum creatinine kinase w/ associated myopathy
Tx Hypothyroidism
Lifelong, oral Levothyroxine (T4)
Start w/ 25 mcg, increase incrementally every 3-6 weeks
AIM is to get TSH = 0.5
w/ 1° - titrate dose until TSH normal
w/ 2° - TSH will always be low, monitor T4
Monitoring Hypothyroidism Tx
T4 half-life is ~7 days
∴ wait ~ 4 weeks to see new TSH levels after dose adjustment
Hashimoto’s Thyroiditis pathophysiology
Cell and antibody mediated autoimmune disease
Causes formation of anti-thyroid antibodies
∴ forming progressive fibrosis
What is Hashimoto’s thyroiditis associated with?
DMT1, Addison’s, Pernicious anaemia
RF Hashimoto’s Thyroiditis
Down’s syndrome
Turner’s
HLA-DR3
Graves’
Ix Hashimoto’s thyroiditis
1st Line = Thyroid Function Tests
↑ TSH, ↓T4
GS = Anti-Thyroid Peroxidase Antibodies
Tx Hashimoto’s thyroiditis
Levothyroxine
What is Diabetic ketoacidosis?
A life-threatening, medical emergency
Signs / Symptoms of DKA
N+V
Severe dehydration - can cause hypotension
PEAR DROP BREATH
Abdo pain
↓ Consciousness
Hyperventilation - Kussmaul’s
Confused
Confusion - could lead to coma
Potassium imbalance
Also, signs of DM - i.e. polyuria, polydipsia etc
What is the associated between DKA and DMT1?
Most common way children w/ DMT1 present is with DKA
Is DKA preventable?
YES, so preventable
Usually occurs when people w/ DMT1 stop insulin (bc of illness/vomiting)
Pxs SHOULD NEVER STOP INSULIN !!!!!!!!!!!
Causes DKA
Untreated DMT1 / Interruption of insulin therapy
Undiagnosed DM
Infection/Illness
Myocardial infection
What is Kussmaul’s breathing?
Deep, laboured breathing pattern at consistent pace
Often associated with severe metabolic acidosis
Ix DKA
Need 3 of the following for diagnosis !! :
1. Hyperglycaemia - BG > 11mmol/L
2. Ketosis - blood ketones > 3mmol/L
3. Acidosis - ABG, pH < 7.3 and/or bicarbonate < 15mmol/L
Clinical features
+ BG measurement
+ Blood gas
DKA Pathology
↓↓↓ Insulin
∴ unrestrained glucose production (hepatic gluconeogenesis)
∴ ↓ peripheral glucose uptake
High levels of circulating glucose
-> Osmotic diuresis by kidneys
∴ DEHYDRATION
Peripheral lipolysis = ↑ FFAs
FFAs oxidised to Acetyl CoA -> ketones
∴ ACIDOSIS
Tx DKA
IMMEDIATE ABC management if unconsciousness
Replace fluid loss w/ 0.9% saline
Replace deficient insulin - give insulin AND glucose (will prevent hypoglycaemia, will both inhibit gluconeogenesis and ∴ ketone production)
Treat underlying triggers - e.g. illness w/ Abx
Why can insulin Tx for DKA cause hypokalaemia?
Why is this dangerous?
Bc insulin decreases K+ levels
K+ goes into cells bc ↑ Na+ pump activity
∴ Hypokalaemia
∴ can lead to arrhythmias etc
Monitoring DKA
Monitor BG closely
Bc therapy can lead to shift of K+ into cells
∴ hypokalaemia
Complications DKA
Cerebral oedema
Cell types of Thyroid Cancers
Papillary
Follicular
Medullary
Lymphoma
Anaplastic
Behaviour
Spread
Prognosis
for Papillary cell Thyroid Cancer
Affects young people
Local spread, followed by pulmonary/skeletal
Good prognosis
Behaviour
Spread
Prognosis
for Follicular Cell Thyroid Cancer
Affects middle aged people, 3x more common in Females
Pulmonary & skeletal (lung/bone)
Usually good prognosis if early but poorer than papillary
Behaviour
Spread
Prognosis
for Medullary Cell Thyroid Cancer
Often familial
Local and metastases (liver, lung, skeletal)
Poor prognosis - depends on age/stage
Behaviour
Spread
Prognosis
for Lymphoma Cell Thyroid Cancer
Variable
/
Usually poor prognosis
Behaviour
Spread
Prognosis
for Anaplastic Cell Thyroid Cancer
Aggressive, mean onset = 65years
Local spread
Very very poor prognosis (avg. survival = 3-8 months)
RFs Thyroid Cancer
Head & neck irradiation
Females
Signs / Symptoms Thyroid Cancer
Palpable thyroid nodule - increased size, hardness and irregularity
Dysphagia
Hoarseness of voice - if tumour presses on recurrent laryngeal nerve
DDx Thyroid Cancer
Goitre
Ix Thyroid Cancer
1st Line = Ultrasound of neck (thyroid)
Fine needle biopsy cytology (to distinguish between benign and malignant)
Laryngoscopy
TFTs - hypo/hyperthyrodism needs to be treated before surgery