Medicine/endocrine Flashcards
Outline calcium homeostasis
Hypercalcaemia causes
- Hyperparathyroidism
- Malignancy – breast, lung, blood, but especially BONE
- Sarcoidosis
- TB
- Rare genetic disorders
- Medications – lithium
- Excessive vit D supplements – BRENDA
Acute hypercalcaemia: Features
Features
- Polyuria
- Polydipsia
- Anorexia, nausea, constipation
- Confusion
- MM weakness
Acute hypercalcaemia: initial investigations
Initial investigations
- A to E
- Assess cognitive function e.g. GCS
- Assess fluid status
- Any examinations that appear relevant from Hx e.g. spine exam if spinal mets suspected
- ECG
- Bloods: calcium, phosphate, PTH, U+Es
Acute hypercalcaemia: management
Management
- Fluid resus consider dialysis if in renal failure
- IV bisphosphonates (stops bone release of Ca) e.g. pamidronate
- Investigate cause
Primary hyperparathyroidism: S&S
Symptoms (Bones, moans and stones)
- Multiple fractures
- Bone pain
- Depression, lethargy, confusion
- Kidney stones
- Polyuria
- Polydipsia
- Anorexia, nausea, constipation
- MM weakness
- But most commonly asymptomatic
Signs
- HTN
- ECG – arrhythmia, short QT
- AKI
- Kidney stones
- MM weakness
- Fragility fractures
- Osteoporosis + osteopenia
- FHx
Primary hyperparathyroidism: investigations,
- Bloods: calcium, phosphate, PTH
- Calculate: calcium clearance to creatinine clearance ratio should be > 0.01 if lower diagnosis is Familial Hypocalcuirc Hypercalcaemia (FHH)
- DEXA scan
- USS of kidneys looking for stones
Primary hyperparathyroidism: complications,
Complications
- Fragility fractures
- AKI
- Peptic ulcer
- Kidney stones
Primary hyperparathyroidism: associated conditions
- Gout
- Pancreatitis
- Metabolic syndrome
Hypocalcaemia: causes
- Acute:
- hyperventilation,
- alkalosis,
- chemo (causes rapid lysis of tumour which causes release of phosphate),
- excessive phosphate intake (enemas),
- blood transfusion with liver disease,
- acute pancreatitis
- Chronic:
- Vit D deficiency,
- CKD,
- hypoparathyroidism (surgery)
Hypocalcaemia: S&S
Signs
- Chvostek’s sign – facial twitch when tapping CN7 (in front of ear)
- Trousseau’s sign – wrist and MCP flexion when BP cuff inflated on arm for several minutes
- Seizures
- Prolonged QT
- Laryngo/broncho spasm
Symptoms
- Parasthesia (fingers, toes and mouth)
- Tetany (mm spasms)
- Carpopedal spasm (wrist flexion and fingers drawn together)
Hypocalcaemia: investigations
Investigations
- Bloods: U+E, amylase, creat kinase, calcium, magnesium, phosphate, PTH
- ECG
Hypocalcaemia: management
- Acute
- A to E
- IV calcium gluconate and calcium
- If present correct hypomagnesia
- If likely to persist oral Vit D
- Monitor urine and serum calcium levels
- Chronic
- Calcium and vit D supplements
- Dietary advice
- Monitor urine and serum calcium levels
Hypothyroidism- Causes, signs, symptoms, treatment
Causes
- Autoimmune (Hashimoto’s)
- Previous thyroid treatment
- Iodine deficiency (not really UK)
- Congenital
- Medications (Lithium, amiodarone, interferons)
Signs
- Bradycardia
- Hyporeflexia
- Oedema
- Hypohydrosis
- Rare:
- Myxoedema coma
- Hoarseness
- Tongue swelling
Symptoms
- Tiredness
- Cold intolerence
- Weight gain
- Constipation
- Depression
- Slow movements + thoughts
- Muscle aches/cramps and weakness
- dry and scaly skin
- brittle hair and nails
- loss of libido (sex drive)
- pain, numbness and a tingling sensation in the hand and fingers (carpal tunnel syndrome)
- irregular periods or heavy periods
Treatment
- Levothyroxine
Hyperthyroidism- Causes, signs, symptoms, treatment
Causes
- Excessive TSH-receptor stimulation
- Graves
- Autonomous Thyroid hormone secretion
- multinodular toxic goitre
- solitary toxic thyroid adenoma
- Destruction of follicles releasing hormone
- subacute de quervain thyroiditis
- hashimoto’s thyroiditis
- Extrathyroidal source of TH
- Iatrogenic
Risk Factors
- Smoking
Signs
- weight loss
- tremor
- palmar erythema
- sinus tachycardia
- lid retraction
- lid lag
Symptoms
- weight loss despite…
- Increased apitite
- heat intolerence
- sweating
- palpatations, tremor
- dyspnoea, fatigue
- irritability
- emotional lability
Treatment
- medication (1st episode, <40yrs old)
- block and replace
- titrate
- surgery
- subtotal thyroidectomy (large goitre, poor drug compliance esp in young, reccurent thyrotoxicosis in young)
- radio-iodine (pt >40 yrs, recurrence post surgery, serious comorbidity)
Management of thyrotoxicosis
Thyrotoxicosis - Extreme hyperthyroidism
Management
- In 1ary care
- Beta blockers for sx
- Refer
- In 2ary care
- Anti-thyriod drugs
- Iodine
- Surgery
Management of subacute thyrioditis
subacute hyperthyroidism - self-limiting inflammation and pain in thyroid
Management for pain
- NSAIDs
- Occasionally systemic glucocorticoids
Thyroid cancer signs, symptoms, investigations, diagnosis, treatment
Signs
compare the hyperparathyroidisms
Thyroid papillary carcinoma prevalence and identifiable features
70%
- Often young females - excellent prognosis
- Usually contain a mixture of papillary and colloidal filled follicles
- Histologically tumour has papillary projections and pale empty nuclei
- Seldom encapsulated
- Lymph node metastasis predominate
- Haematogenous metastasis rare
Thyroid follicular adenoma/carcinoma prevalence and identifiable features
adenoma + carcinoma - 20%
Adenoma
- Usually present as a solitary thyroid nodule
- Malignancy can only be excluded on formal histological assessment
Carcinoma
- May appear macroscopically encapsulated, microscopically capsular invasion is seen. Without this finding the lesion is a follicular adenoma.
- Vascular invasion predominates
- Multifocal disease raree
Thyroid medullary carcinoma prevalence and identifiable features
5%
- Cancer of parafollicular (C) cells, secrete calcitonin, part of MEN-2
- C cells derived from neural crest and not thyroid tissue
- Serum calcitonin levels often raised
- Familial genetic disease accounts for up to 20% cases
- Both lymphatic and haematogenous metastasis are recognised, nodal disease is associated with a very poor prognosis.
Thyroid anaplastic carcinoma prevalence and identifiable features
1%
- Not responsive to treatment, can cause pressure symptoms
- Most common in elderly females
- Local invasion is a common feature
- Treatment is by resection where possible, palliation may be achieved through isthmusectomy and radiotherapy. Chemotherapy is ineffective.
Thyroid lymphoma prevalence and identifying features
Rare
Associated with hashimotos
Management of papillary and follicular cancer
- total thyroidectomy
- followed by radioiodine (I-131) to kill residual cells
- yearly thyroglobulin levels to detect early recurrent disease
Diabetes insipidus: definition, cause, s&s, investigations
Definition - defective release/synthesis (central DI) or renal insensitivity (nephrogenic) to AVP/ADH/Vasopressin
Cause
- Central - physical damage (surgery, tumour etc.) or auto immune (wolfram’s syndrome), genetic
- Nephrogenic - nephrotoxic drugs (lithium), CKD, chronic hypercalcaemia, genetic
S&S - polydipsia, polyuria, increased thirst, and formation of hypotonic urine
Investigations
- urine osmolality - low
- 24 hour urine collection - high volume >3L
Note desmopressin is the synthetic form of vasopressin
Conn’s syndrome: Definition, cause, s&s, investigations
Definition - Increased production of aldosterone
Cause - Unknown
S&S - HTN, polyurea,
Investigations
- Potassium - low/normal
- aldosterone/renin ratio - High
Acromegaly: definition, cause, s&s, investigations
Definition - excess growth hormone
Cause - pituitary somatotroph adenoma
S&S - coarsening of facial features, skin changes, carpal tunnel, arthralgia, snoring, change in sexual function
Investigations
- Serum insulin like GF (IGF-1) - elevated
- Oral glucose tolerance test - GH >1 (lack of supression)
- Random serum GH - elevated
Cushing’s: definition, cause, s&s, investigations
Definition - hypercortisolism
Cause - most commonly adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma
S&S - central obesity with insulin resistance, and hypertension, proximal muscle weakness, supraclavicular fat pads, moon-shaped face, violaceous striae, easy bruising, and premature osteoporosis.
Investigations
- Late night salivary cortisol - elevated
- Dexamethasone supression test - cortisol remains elevated
- 24 hour urinary free cortisol - elevated
Prolactinoma: definition, cause, s&s, investigations
Definition - prolactin secreting pituitary tumour
Cause - idiopathic
S&S - amenorrhoea, infertility, galactorrhoea, loss of libido, temporal hemianopia
Investigations
- Serum prolactin
- Pituitary MRI
Phaeochromocytoma - definition, causes, s&s, investigations
Definition - catecholamine (adrenaline) secreting tumour of adrenal gland
Causes
- Multiple endocrine neoplasia type 2
- Von Hippel-Lindau syndrome
- Neurofibromatosis type 1
S&S - headache, palpatations, sweating, HTN, DM2
Investigations
- Urine and serum catecholamines, metanephrines, and normetanephrines - elevated
Addisons: definition, causes, s&s, investigations
Definition - Auto-immune adrenal insufficiency causing decreased production of adrenalcortical hormones (cortisol, aldosterone and dehydroepiandrosterone)
Causes - Usually auto-immune
S&S - fatigue, anprexia, wgt loss, hyperpigmentation, hypotension, N&V
Investigations
- U&Es - low Na, high K, sometimes high Ca
- FBC - anaemia, eosinophilia
- Morning serum cortisol - low
Congenital Adrenal Hyperplasia: definition, cause, S&S, investigations
Definition - Umbrella term for a group of enzyme deficiencies resulting from impraired corticosteriod synthesis from the adrenal cortex. Most commonly 21-hydroxylase deficiency
Cause - genetic
S&S - FHx, wgt loss, FTT, hypotension, ambiguous genitalia, hyperpigmentation, irregular menses, infertility, early puberty
Investigations
- serum 17-hydroxyprogesterone - elevated
- serum 11-deoxycortisol - elevated
- U&Es - low Na, high K, metabolic acidosis
- rapid ACTH stimulation test - high hydroxyprogesterone
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Effects of steriods on endocrine and therefore what happens when you stop taking them suddenly
Steriods (prednisone, dexamethasone, hydrocortisone) cause adrenal suppression through negative feedback loop.
Too much steriod causes cushings (excess cortisol) because that’s essentially what it is
If you suddenly stop taking steriods your body’s adrenal glands won’t be able to keep up. This causes adrenal insufficiency, which can look like addisons
Endocrine axis summary
SIADH: definition, causes, s&s, investigations
Definition - Untrolled production of ADH/AVP/vasopressin
Causes
- Brain damage e.g. stroke
- Malignancy SCC of lung
- Lung and brain infection
- Hypothyroidism
S&S
Signs - Dec GCS, hypervolaemia
Symptoms - Nausea / Vomiting / Headache / Anorexia / Lethargy/Muscle cramps / Weakness / Confusion / Ataxia/Drowsiness / Seizures / Coma
Investigations
- Serum sodium - low
- Plasma osmalilty - low
- Urine osmalilty - high
