Endo1 Flashcards
Diabetes
What is diabetes insipidus?
Inadequate secretion or insensitivity to vasopressin, causing hypotonic polyuria
What is the vasopressin pathway?
ADH is created in the hypothalamus
ADH is secreted in the posterior pituitary
ADH binds to the kidney and increases water reabsorption
Urine osmolality is raised
Serum osmolality is decreased
What are the two types of diabetes insipidus?
Cranial
Nephrogenic
What are the causes of cranial DI?
Posterior pituitary fails to secrete ADH
Due to: pituitary tumour, infection, sarcoidosis
What are the causes of nephrogenic DI?
Collecting ducts insensitive to ADH
High Ca, low K, lithium, inherited (AVPV2 gene), idiopathic
What is the presentation of DI?
Polyuria
Nocturia
Polydipsia
Lethargy/irritability/confusion (high Na)
What are the investigations for DI?
U+E
Glucose
Water deprivation test
What happens during water deprivation of a normal Pt?
Urine becomes concentrated
osm >600
What happens during water deprivation of a Pt with cranial DI?
Kidneys are unable to concentrate the urine
osm <400
What happens during water deprivation of a Pt with nephrogenic DI?
Kidneys are unable to concentrate the urine
osm <400
What do you give a Pt for the second part of the water deprivation test?
Desmopressin
What happens when you give desmopressin to a Pt with cranial DI?
Urine osm raises by >50% after desmopressin
What happens during water deprivation of a Pt with nephrogenic DI?
Urine osm raises by <45% after desmopressin
What is the management for DI?
Treat the cause eg.
Cranial- intranasal desmopressin
Nephrogenic- thiazide diuretic or NSAIDs
What is T1DM?
Hyperglycaemia due to a deficiency of insulin production (90% autoimmune destruction of B cells)
What is T2DM?
Hyperglycaemia due to a resistance to insulin action
What is the presentation of T1DM?
Polydipsia
Polyuria
Tired/weight loss
DKA
What are the clinical features of a DKA?
N+V
Kussmaul breathing
Ketone breath
Abdo pain
What is the presentation of T2DM?
Polydipsia
Polyuria
What are the risk factors for T1DM?
HLD DR3/4
Other autoimmune conditions
What are the risk factors for T2DM?
Obesity FHx Ethnicity Endocrine Drugs
How is diabetes mellitus diagnosed?
Blood glucose measurement
Fasting >= 7.0mmol/L
Random > 11.1mmol.L
What is the management for T1DM?
Insulin
Patient education
What is the management for DKA?
Fluids
What is the management for T2DM?
Diet and lifestyle
Metformin/sulphonylurea/insulin
How can you categorise hyponatraemia?
Hypovolaemia
Euvolaemia
Hypervolaemia
What are the causes of hypovolaemic hyponatraemia?
Diarrhoea
Vomiting
Diuretics
What are the causes of euvolaemic hyponatraemia?
Hypothyroidism
Hypoadrenalism
SIADH (pneumonia, cancer)
What are the causes of hypervolaemic hyponatraemia?
HF
Cirrhosis
Nephrotic syndrome
What are the signs of hypovolaemic hyponatraemia?
Reduced turgor
Postural hypotension
Dry mucous membranes
What are the signs of hypervolaemic hyponatraemia?
Oedematous
High JVP
What are the investigations for hypovolaemic hyponatraemia?
Urine sample
-low Na as body tried to retain Na due to hypovolaemia
What are the investigations for euvolaemic hyponatraemia?
TFTs
synACTHen test
Drug review, breast exam, CXR, brain MRI
What should you do if a Pt is severely hyponatraemic?
Give slow hypertonic saline
What should you be careful for when giving a Pt hypertonic saline and why?
Do not exceed 10mmol/L in the first 24h
Risk of central pontine myelinosis
What are the complications of hyponatraemia?
Seizures
Decreased consciousness
What are the causes of hypernatraemia?
Vomiting Diarrhoea Burns Diabetes insipidus Primary aldosteronism
What is the presentation of hypernatraemia?
Lethargy Irritability Thirst Signs of dehydration Confusion Coma Fits
What is the management for hypernatraemia?
Replace the water
What is SIADH?
Too much ADH, causing too much water reabsorption
Low serum Na, high urine osm, high urine Na
NB: SIADH is not a final diagnosis
What are the causes of SIADH?
CNS pathology
Lung pathology
SSRI, TCA, opiates, PPIs, carbamazepine
Tumours (eg. breast cancer)
What is the management for SIADH?
Treat the underlying cause
Fluid restrict to 0.5-1L
If ineffective, give demeclocycline/tolvaptan
What is the prolactin axis/pathway?
Hypothalamus -> TRH -> anterior pituitary
Anterior pituitary -> prolactin -> hypothalamus
Hypothalamus -> dopamine -> inhibits anterior pituitary
What are the causes of hyperprolactinaemia?
Pituitary prolactinoma
Hypothyroidism
Metoclopramide/antipsychotics
Pregnancy, breast feeding
What are the clinical features of female hyperprolactinaemia?
Galactorrhoea, amenorrhoea, infertility, loss of libido
Headache, visual field loss
What are the clinical features of female hyperprolactinaemia?
Loss of libido, infertility
Headache, visual field loss
What are the investigations for hyperprolactinaemia?
Prolactin
TFTs
Pituitary MRI
What is the management for hyperprolactinaemia?
DA agonist (bromocriptine/cabergoline) Surgery
What is the thyroid axis/pathway?
Hypothalamus -> TRH -> anterior pituitary
Anterior pituitary -> TSH -> thyroid gland
Thyroid gland -> hormones -/> HP/AP
What is hyperthyroidism?
Excess circulating T4/3 due to:
- increased hormone synthesis (hyperthyroidism)
- increased release of stored hormones (thyroiditis)
What are the signs and symptoms of hyperthyroidism?
Heat intolerance/sweating Palpitations, irregular pulse Irritable Weight loss, good appetite Diarrhoea Menstrual irregularity/impotence Tremor
What are the signs and symptoms of hypothyroidism?
Cold intolerance Bradycardia Lethary Weight gain Constipation Menstrual irregularity Dry skin/cold hands
What are the types of hyperthyroidism?
Grave’s disease (80%)
De Quervain’s thyroiditis
Toxic multinodular goitre
Adenoma
What is Grave’s disease?
Antibodies to TSH receptors
What is Grave’s triad?
Exophthalmos
Pretibial myxoedema
Thyroid acropachy
What is De Quervain’s thyroiditis?
Post-viral inflammation
High ESR
Causes painful goitre
Self limiting, treated with NSAIDs
What is a toxic multinodular goitre?
Goitre seen in the elderly/iodine deficient areas
What is a thyroid adenoma?
Solitary nodule secreting T3/4
What will you see on a radioisotope scan of Grave’s disease?
Diffuse increased uptake
What will you see on a radioisotope scan of De Quervain’s thyroiditis?
No uptake
What will you see on a radioisotope scan of a toxic multinodular goitre?
Multiple areas of increased uptake
What will you see on a radioisotope scan of a thyroid adenoma?
Single area of increased uptake
What are the causes of hypothyroidism?
Autoimmune Hasimoto's thyroiditis Iodine deficiency Iatrogenic (post-surgery, radioiodine, amiodarone) De Quervain's thyroiditis Congenital thyroid dysgenesis
What is the commonest cause of hypothyroidism in the West?
Autoimmune Hasimoto’s thyroiditis
What is the commonest cause of hypothyroidism in the worldwide?
Iodine deficiency
What is the management for hypothyroidism?
Levothyroxine 25-200 micrograms/day
What is a myxoedema coma?
Severe hypothyroid state, usually seen in the elderly
What is the presentation of a myxoedema coma?
Hypothermia Hypoventilation Hyponatraemia Heart failure Confusion Coma
What is the treatment for a myxoedema coma?
Oxygen Rewarm Rehydrate IV T3/4 IV hydrocortisone
What are the types of thyroid cancer?
Papillary Follicular Medullary Lymphoma Anaplastic
What are the characteristics of a papillary thyroid cancer?
Most common
Affects younger Pts
Radiation exposure is a great risk factor
Psammoma bodies and Orphan Anne nuclei seen on microscopy
What are the characteristics of a follicular thyroid cancer?
Affcts middle aged women
Hurthle cells seen on microscopy
What are the characteristics of a medullary thyroid cancer?
Association with MEN2
What are the characteristics of a thyroid lymphoma?
Most common in females
Usually occurs after pre-existing Hashimoto’s
What are the characteristics of a anaplastic thyroid cancer?
Seen in elderly females
Giant cells and pleomorphic hyerchromatic nuclei on microscopy
What is acromegaly?
Hypersecretion of growth hormone in adults, usually a pituitary adenoma
GH stimulates IGF-1 causing the growth of bone and soft tissue
What is gigantism?
Hypersecretion of growth hormone in children
What is the presentation of acromegaly?
Ring and shoes become tight Increased sweating Coarse facial features Sleep apnoea Weight gain Headaches/visual disturbance Carpal tunnel syndrome Hypertension Insulin resistance
What are the investigations for acromegaly?
Serum IGF-1
OGTT -> failed GH supression
Pituitary MRI
What is the treatment for acromeglay?
Transphenoidal hypophysectomy
Octreotide (somatostatin analogue)
What is multiple endocrine neoplasia?
An autosomal dominant condition with hormone-producing tumours in multiple organs
What is MEN1?
PPP
Mutation in menin gene Chr 11
Parathyroid adenoma/hyperplasia: hyperparathyroidism, high Ca
Pancreas: insulinoma, gastrinoma
Pituitary: prolactinoma, acromegaly, adrenal, carcinoid tumours
What is MEN2A?
TAP
Thyroid: medullary thyroid cancer (in ALL)
Adrenal: phaeocytochroma
Parathyroid hyperplasia
What is MEN2B?
Medullary thyroid carcinoma and phaeo
+mucosal neuroma: bumps on lips/cheeks/tongue/eyelids
+Marfanoid appearance
No hyperparathyroidism
What is carcinoid syndrome?
Multiple symptoms from a systemic release of humoral factors from carcinoid tumours
They can produce serotonin, histamine, tachykinin, prostaglandin
What are the common sites of carcinoid tumours?
Appendix
Rectum
What is the presentation for carcinoid syndrome?
Paroxysmal flushing Diarrhoea Crampy abdo pain Wheeze Sweating Palpitations
What are the investigations for carcinoid syndrome?
24h urine collection- raised 5-HIAA levels (serotonin metabolite)
CT/MRI- localise tumour
A 49 year-old man presents with a history of difficulty sleeping. He reports feeling increasingly tired and general weakness which he attributes to his poor sleep pattern. Additionally, the patient has noticed he has gained weight and sweats more easily. On examination, the patient has coarse facial features. What is the most likely diagnosis?
A. Hyperthyroidism B. Cushing’s disease C. Acromegaly D. Hypothyroidism E. Diabetes
C. Acromegaly
A 50 year old Asian man is referred to diabetes clinic after presenting with polyuria and polydipsia. He has a BMI of 30, a blood pressure measurement of 137/88 and a fasting plasma glucose of 7.7mmol/L. The most appropriate first-line treatment is:
A. Dietary advice and exercise B. Sulphonylurea C. Exenatide D. Thiazolidinediones E. Metformin
A. Dietary advice and exercise
A 15 year old girl complains of headaches which started 6 weeks ago. The headaches initially occurred 1-2 times a week but now occur up to five times a week, they are not associated with any neurological problems, visual disturbances, nausea or vomiting. The girls also reports a white discharge from both of her nipples. She has not started menstruating. The most appropriate investigation is:
A. Lateral skull X ray B. CT scan C. MRI scan D. Thyroid function tests E. Serum prolactin measurement
E. Serum prolactin measurement
A 6 year old girl presents to A&E with severe abdominal pain, nausea and vomiting. On examination, the patient is tachypnoeic, capillary refill is 3 seconds and she has a dry tongue. While listening to the patient’s lungs you detect a sweet odour from her breath. The most likely diagnosis is:
A. Diabetic ketoacidosis B. Non-ketotic hyperosmolar state C. Gastroenteritis D. Pancreatitis E. Adrenal crisis
A. Diabetic ketoacidosis
A 58 year old woman presents with an acutely painful neck, the patient has a fever, blood pressure is 135/85, and heart rate is 102 bpm. The patient explains the pain started 2 weeks ago and has gradually become worse. She also experiences palpitations and believes she has lost weight. She presents one week later complaining of intolerance to cold temperatures. What would you see if you performed a radioisotope scan on her?
A. Single area of increased uptake B. Multiple areas of increased uptake C. Diffuse increased uptake D. No uptake E. She does not need a radioisotope scan
D. No uptake
A 72 year old man is brought to A&E because his carer noticed that recently he has become increasingly lethargic, irritable and confused. On examination he has a raised JVP and bibasal crackles. He suffered from a myocardial infarction 3 years ago.
Blood results are as follows:
Na 125 mmol/L
Urea 3
K 4 mmol/L
Glucose (fasting) 6 mmol/L
What is the most likely cause of his hyponatraemia:
A. SIADH B. Hypothyroidism C. Nephrotic syndrome D. Heart failure E. Diabetes
D. Heart failure
