Endocrinology Flashcards
MEN syndromes
MEN I (3 Ps) – Pituitary, Parathyroid, Pancreas
MEN IIa (1M,2Ps) – Medullary Thyroid Carcinoma, Pheochromocytoma, Parathyroid
- OR “I am meant to sit in an AC room” – 3Cs Calcium, Calcitonin, Catecholamines
MEN IIb (2Ms,1P) – Medullary Thyroid Carcinoma, Marfanoid habitus/mucosal neuroma, Pheochromocytoma
- Every man wants to be a Pharaoh with Medium Cars on Mars with New Romans”
Management of Hypoglycaemia
Whipple’s triad
- Plasma hypoglycaemia
- Symptoms due to low blood glucose
- Resolution of symptoms with correction of hypoglycaemia
Known hypopituitarism –> Gradual onset
Pituitary apoplexy sudden onset
Panhypopituitarism
Reduced GCS
Hypotension
Hypoglycaemia
Diagnosis? Tx?
Hypopituitary coma
- URGENT IV Hydrocortisone
- Then, T3 replacement
- Then treat underlying cause
Simmond’s disease
vs
Sheehan’s syndrome
vs
Pituitary apoplexy
-
Simmond’s disease
- Insidious onset
- Hypopituitarism
-
Sheehan’s syndrome
- Women
- PPH
- Sudden onset
- Hypopituitarism
-
Pituitary apoplexy
- Pre-existing pitutiary adenoma –> acute infarction
- Rapid onset
- Headache
- Xanthochroma
- Hypopituitarism
Ix for GH deficiency
Tx
Insulin (hypoglycaemia is a potent stimulus for GH release)
Normal = GH release
Pituitary dwarfism –> no GH release
Tx: Somatotropin (recombinant GH)
Excess GH is associated with
High levels of GH has prolactin-like effects
Ix for Acromegaly
IGF-1: high (inital Ix)
OGTT (definitive Ix)
- Normal: Glucose load –> ↓ GH levels
- Acromegaly: Glucose load –> Paradoxical ↑ GH levels
Tx for acromegaly
(1) Trans-sphenoidal surgery
(2) Somatostatin analogue (Octreotide) or Cabergoline (DA agonist)
(3) GH antagonist
(4) Radiotherapy
Complications of Acromegaly
Cardiac complications (40%)
Diabetes mellitus
Colonic adenocarcinoma
Micro vs Macroadeoma
Hypothalamic - Pitutiary axes
Signs of hypernatraemia
- Thirst
- Loss of appetite
- Restlessness
- ↑ Tone (Spasticity)
- Hyper-reflexia
- Tremor
- Seizures
- Ataxia
- Lethargy –> Stupor –> Coma
Signs of hyponataremia
If Na+ < 120 mM –> Generalised weakness, Poor mental function, N&V, Irritability
If Na+ < 110 mM –> Confusion, Drowsiness, Seizures, Coma (↓ GCS), Death
SALT LOSS
- Stupor
- Anorexia
- Lethargy
- Tendon reflexes ↓
- Limp muscles (weakness)
- Orthostatic hypotension
- Seizures
- Stomach cramps
Signs of hypokalaemia
ECG changes
Tx
Sx
- Muscle weakness
- Cardiac arrhythmias
- Polyuria/Polydipsia
- Constipation
ECG
- Prolonged PR
- Flattening of T wave
- ST depression
- U wave
Tx
- Oral/IV Potassium chloride (<10mmol/hr)
- Treat underlying cause
Sx and ECG changes of hyperkalaemia
ECG:
- Bradycardia
- Loss of p waves / Flattened p waves
- Prolonged PR
- Broad QRS
- Depressed ST
- Peaked T waves
Sx of hyperkalaemia MURDER
- Muscle cramps –> Weakness –> Paralysis
- Drowsiness
- Hypotension
- Arrhthmias
- Abdominal cramps
- Diarrhoea
- Oliguria
Ix for diabetes insipidus
Serum osmolality: ↑
Urine osmolality: ↓ (i.e. dilute urine)
Tx for DI
Cranial DI –> Desmopressin
Nephrogenic DI –> Thiazide diuretics (Bendroflumethiazide)
==> retain urine volume and bypass VP’s concentrating mechanism
Ix in SIADH
Examination findings
- Plasma osmolality: ↓ plasma osmolality, ↓ Na+
- Urine osmolality: ↑ urine osmolality, ↑ Urine Na+
- Euvolaemic
Tx
- Treat underlying cause
-
Treat hyponataremia
- Fluid restriction
- +/- IV Hypertonic 3% saline
- Avoid increasing Na too quickly (central pontine myelinolysis)
- +/- Furosemide
- Long term –> cause nephrogenic DI
- Lithium
- DMCT
- Tolvaptan
Sx of hypopituitarism
Tx for thyroid storm
- ABCDE
-
High-dose anti-thyroid drug (Aim to remove excess T4/T3 QUICKLY)
- Carbimazole
- Propylthiouracil
- + Corticosteroids
- + β-blockers
- + Iodine (Lugol solution)
Tx for Grave’s disease
- Anti-thyroid drugs (Carbimazole or Propylthiouracil)
- High dose and titrate or Block and replace
- Takes time to work due to existing T4/T3 in colloid
- Given with B-blockers
- β blockers (Propranolol)
- Radioactive iodine
- Surgery
Smooth diffuse goitre
Fever (ALWAYS PRESENT)
Extreme agitation
Confusion / Delirium
Nausea & Vomiting
Tachycardia
Cardiac failure
Liver failure / Jaundice
Signs of dehydration / volume depletion
Diagnosis?
Thyroid storm
Thyroid scan in
Grave’s
Plummer’s (toxic nodular goitre)
Toxic adenoma
Grave = smooth uptake
Plummer’s (toxic nodular goitre) = hot nodules and cold areas
Toxic adenoma = hot nodule
Viral thyroiditis = no uptake
Thyroid goitre Ix
TFTs
Neck USS +/- Fine needle aspiration
Thyroid scan
Tx for toxic nodule
- Medical
- Anti-thyroid drugs (Carbimazole, Propylthiouracil)
- Beta-blockers
- Radio-iodine
- Surgical
- Subtotal/Total Thyroidectomy
Antibody in Hashimoto’s thyroiditis
Anti-TPO Ab / Anti-thyroglobulin Ab: +ve
Causes of Cushing’s syndrome
- ACTH dependent
- Pituitary adenoma (Cushing’s disease)
- Ectopic ACTH production
- ACTH indepedent
- Iatrogenic / Exogenous steroids
- Adrenal adenoma
Ix for Cushing’s syndrome
- 24 hour urine cortisol
- 9am and Midnight cortisol
- Low dose dexamethasone supression test (Gold standard)
- High dose dexamethasone supression test
Adrenal adenoma
- ↓ ACTH
- ↑ Cortisol
Ectopic ACTH
- ↑ ACTH
- ↑ Cortisol – remains high in high-dose suppression test
Cushing’s disease
- ↑ ACTH
- ↑ Cortisol on low dose suppression BUT supressed on high-dose suppression test
Tx for Cushing’s syndrome
- Conservative
- If iatrogenic –> ↓ steroid dose
- Medical
- Metyrapone (↓ Cortisol synthesis, ↑ aldosterone, ↑ adrenal androgens)
- Ketoconazole (↓ Cortisol synthesis, ↓ aldosterone, ↓ adrenal androgens)
- Surgical
- If Cushing’s disease –> Trans-sphenoidal hypophysectomy
- If ectopic ACTH –> remove tumour
- If adrenal adenoma –> adrenalectomy
- If non-operable –> Radiotherapy
Tx of Conn’s syndrome
- Medical
- MR antagonist
- Spironolactone
- Epleronone
- Anti-hypertensives
- MR antagonist
- Surgery
- Laparoscopic adrenalectomy: remove the tumour
N.B. If bilateral adrenal hyperplasia, stay on spironolactone (do not remove both adrenals as cannot respond to stress)
Palpitations
Headache
Episodic sweating (diaphoresis)
Episodic severe hypertension (may cause stroke)
Diagnosis? Ix? Tx?
Phaeochromocytoma
24 hour urinary catecholamines (adrenaline, noradrenaline, dopamine) : ↑
Plasma catecholamines levels: ↑
Long term
- Pre-operative
- FIRST, α blockade (Phenoxybenzamine)
- THEN, β blockade (Propanolol)
- Surgery
- Laparoscopic adrenalectomy
Vomiting
Abdo pain
Tachycardia
Weakness
Pale, Cold, Clammy, Oliguria
Hypoglycaemia
Hypovolaemic shock
+/- Trigger
Diagnosis? Ix? Tx?
Addisonian crisis
↓ Na+, ↑ K+
- High dose IV Hydrocortisone
-
IV 0.9% saline (1L over 30-60min)
- Aim to restore BP & replace salt that is lost
-
5% Dextrose (prevent hypoglycaemia)
*
Ix and Tx of Addion’s disease
Ix
-
9am cortisol
- If normal: HIGH (normally high in the morning)
- Addison’s: LOW Cortisol (< 100nmol/L is diagnostic)
-
ACTH
- Addison’s (Primary): HIGH ACTH
-
SynACTHen test + Measure Cortisol (before & after)
- If normal: ↑ cortisol
- If Addison’s: no/little increase
Tx for Addisonian crisis
- High dose IV Hydrocortisone
- IV 0.9% saline (1L over 30-60min)
- 5% Dextrose (prevent hypoglycaemia)
Long term Tx
-
Hydrocortisone (replace glucocorticoid)
- Advice: Increase dosage if (1) acute illness or (2) surgery or (3) stress
- Fludrocortisone (replace mineralocorticoid)
↓ Na+, ↑ K+
Hypotension + Hyperkalaemia
Diagnosis? Causes?
Addison’s disease
Autoimmune
TB
Iatrogenic
Hypertension
Hypokalaemia
Diagnosis?
Hyperaldosteronism
- Primary
- Conn’s
- Bilateral adrenocortical hyperplasia
- Secondary
- RAS
- Renin-secreting tumour
Steroid synthesis pathway
Complete 21-OH deficiency (most common)
Sx
Ix
Tx
Partial 21-OH deficiency
11-OH deficiency
17-OH deficiency
Causes of hypercalcaemia
Sx and Tx of hypercalcaemia
Sx
- Bones - bone pain +/- fractures
- Stones - renal calculi
- Abdo moans - constipation, pancreatitis
- Psychic groans - confusion, seizures, coma
- Thrones - polyuria, polydipsia
Tx
- IV 0.9% saline ++++++++++
-
+/- Bisphosphonates
- ONLY indication = Hypercalcaemia of Malignancy
- Otherwise avoid!
- Treat underlying cause
Hypocalcemia - Sx, Causes, Tx
- CATS go numb
- Convulsions
- Arrhythmias
- Tetany
- Trousseau’s
- Chvostek’s
- Paraesthesia
- Causes
- ↓ Ca2+ and ↑ PTH
- Vitamin D deficinecy
- CKD
- Pseudohypoparathyroidism (PTH resistance)
- ↓ Ca2+ and ↓ PTH
- Surgical (post-thyroidiectomy)
- ↓ Ca2+ and ↑ PTH
- Tx
- Ca - IV Calcium Gluconate
- Vitamin D
-
Bone pain and tenderness
- Typically lower extremities, lower spine, ribs & pelvis
- Proximal myopathy / Muscle wasting
- Waddling gait
- ↑ risk of fractures
-
Signs of hypocalcaemia
- Trousseau’s sign
- Chvostek’s sign
Diagnosis? Ix? Tx?
Ostemalacia (Vitamin D deficiency)
↓ Ca2+ , ↓ PO43- , ↑ ALP
Tx: Vitamin D
Types of Vitamin D supplementation
- If normal renal function, give precursor (they can convert)
- Ergocalciferol (25 OH D2)
- Cholecalciferol (25 OH D3)
- If renal failure (inadequate 1𝝰 hydroxylation)
- Alfacalcidol
Types of hyperparathyroidism
X-ray changes in Primary hyperparathyroidism
- Pepper pot skull (diffuse porotic mottling of skull)
- Rugger jersey spine (sclerosis of sup / inf vertebral margins w central deminerlisation)
Pathology and Signs of pseudohypoparathyroidism
PTH resistance
Hypocalcaemia
Abnormal 4th and 5th metacarpal joint
“Knuckle knuckle dimple dimple” sign
Osteoporosis - Sx, Ix, Tx
Osteoporosis
Asymptomatic until fracture
Ix
- DEXA score (T score < -2.5 (healthy reference) and Z-score (age-matched control)
- Normal Ca2+, PO43-, ALP
- FRAX score / QFRACTURE tool
Tx
- (1) Bisphosphonates
- + Ca and Vitamin D supplementation
- (2) Denosumab (RANKL inhibitor –> inhibitor osteoclasts)
- (3) Teriparatide (recombinant PTH –> osteoblasts > osteoclasts)
- Strontium ranelate
- SERMs
- HRT
Paget’s disease
X-ray changes
Biochemistry
Tx
Cx
ALP: ↑↑↑
Ca2+ & PO43-: normal
PTH: normal
Vitamin D: normal
X-ray: Cotton-wool appearance
Tx: Bisphosphonates +/- Analgesia
Cx: Fractures, Osteosarcoma (1%), Sensorineurlal deafness
Definitions of diabetes
- Fasting blood glucose: > 7 mmol/L in Diabetes
- OGTT: > 11.1 mmol/L in Diabetes
-
HbA1c: > 48 mmol/mol is diagnostic for Diabetes (> 6.5%)
*
Tx for T2DM
(1) Diet & Exercise
(2) Metformin
(3) See image
Complications of T2DM
Tx of Hypoglycaemia
Altered mental status (Confusion ==> Coma)
Severely dehydration
Hyperglycaemia
↑↑ osmolality
↑ Na+
No ketones
Diagnosis? Tx?
Hyperglycaemic Hyperosmolar State
-
IV 0.9% saline
- Rehydrate with normal saline SLOWLY
- If corrected too quickly –> cerebral oedema (high mortality)
- If blood glucose is not falling ==> IV Insulin
- +/- Anticoagulation
Diabetic retinopathy - Stages, Findings, Tx
Diabetic nephropathy
Features
Ix
Tx
Sx
- Progressive proteinuria
- ↑BP
Ix
- Albumin:Creatinine ratio (ACR)
- eGFR
- Proteinuria
Tx
- ACE inhibitors (aim for BP < 130/80mmHg)
Diarrhoea
Flushing
+/- Wheezing
Abdo Pain
Telangiectasia
Diagnosis? Ix? Tx?
Carcinoid syndrome
Ix:
-
Serum Chromogranin A/B: ↑
- Tumour marker
-
24hr urine collection of 5-hydroxyindoleacetic acid: ↑
- 5-hydroxyindoleacetic acid is a serotonin metabolite
Tx
- Acute
- IV Octreotide +/- IV Hydrocortisone
- Long-term
- Surgical resection
Tx for Obesity
- Conservative
- Diet & Exercise
- Medical
- Orlistat: lipase inhibitor –> ↓ absorption of dietary fat
- Lorcaserin: serotonin receptor agonist –> ↓ appetite
- Liraglutide: GLP-1 receptor agonist –> ↓ appetite
- Manage comorbidities
- Surgical
- Criteria:
- BMI > 40
- All other measures ineffective
- Fit for anaesthesia and surgery
- Committed to need for long-term follow up
- Options
- Roux-en-Y gastric bypass
- Adjustable gastric banding (Laparoscopic)
- Sleeve gastrectomy
- Duodenal switch with biliopancreatic diversion
- Criteria:
Tx for hypercholesterolaemia / hyperlipidaemia
(1) Statins
(2) Ezetimibe
(3) Fibrates (Gemfiibrozil)
DDx Goitre
- Iodine deficiency
- Autoimmune
- Grave’s disease
- Hashimoto’s
- Infection
- Viral thyroiditis
- Malignancy
- Pituitary adenoma
- Physiological
- Pregnancy
- Puberty
