endocrinology Flashcards
Increased sweating is seen in:
MenopausePhaeochromocytoma AcromegalyTyrotoxicosisInsulinoma –> hypoglycaemia
Foods high in potassium
BananasFresh orange juiceCitrus fruitsAvocados
Appropriate screening for Cushing’s syndrome
1mg overnight dexamethasone suppression test - given at 11pm - then measure cortisol at 9am <50 nmol/L = normal
Hypothalamic hormones
Dopamine Corticotrophin releasing hormoneGH releasing hormonegonadotropin releasing hormoneThyrotrophic releasing hormoneSomatostatinOxytocin (produced here + secreted by post pituitary) Antidiuretic hormone (produced here + secreted by post pituitary)
Posterior pituitary hormones
OxytocinAntidiuretic hormone (ADH) (vasopressin)
Anterior pituitary hormones
Adrenocorticotrophic hormone (ACTH) Follicle stimulating hormone (FSH)Growth hormone (GH) Leutenising hormone (LH) Thyroid stimulating hormone (TSH) Melanocyte stimulating hormone (MSH) Prolactin
What is 9 AM cortisol measured for?
Adrenal insufficiency.Addisons
What is a dexamethasone suppression test used for?
Cushing’s syndrome.
What is a short synacthen test used for?
Addison’s disease
What is kallmanns syndrome
Failure of episodic GnRH secretion (hypogonadotrophic hypogonadism) + anosmia (absent olfactory bulb) M:F 4:1
Three circumstances leading to the release of renin
1) decreased renal perfusion pressure 2) Sympathetic nervous system activation due to decreased arterial BP3) decreased Na delivery to macula densa
Management of hyperkalaemia
IV calcium gluconate - 10ml 10%IV insulin + dextrose - 10U actrapid in 50ml 50%Nebulised salbutamol -10mgCalcium resonium + lactulose (Furosemide + fluids)(Haemodialysis)
ECG features of hyperkalaemia
Flat P wavesBroad QRSslurred ST segmentTented T-wave
obesity is associated with a higher risk of what medical conditions?
OADMbreast carenal caprostate cahypertensiondepression
features of hyperprolactinoma
amenorrhoeamilk production
Diagnostic criteria of metabolic syndrome
BP > 130/85HDL 1.7fasting blood glucose >6.6waist circ >88cm in F or 102 in M
Primary amenorrhoea and anosmia occurs in…..
Kallmann’s syndrome
What does the testis secrete
TestosteroneAndrostenedione oestradiolInhibinProgesterone (small amount)
What is a phaeochromocytoma
Catecholamine secreting neuro-endocrine tumourIn adrenal medulla V rare
Presentation of pheochromocytoma
Palpitations, tachycardia, anxiety and blanchingHypertensive crisisLeft ventricular hypertrophy on ECG
Presentation Cushing’s syndrome
Weight gain, muscle weakness, hirsutism, Menstrual irregularities, mood disturbanceMoon FaceInterscapular Fat padThin skinEasy bruisingPurple striaeOsteoporosis and pathological fractures
What is Cushing’s syndrome?
Glucocorticoid excess.
What is Cushing’s disease?
Pituitary tumour secreting ACTH
Causes of Cushing’s syndrome?
Cushing’s disease = pituitary tumour Secreting ACTHSmall-cell carcinoma secreting ACTHIatrogenic steroidsAdrenal adenoma or Carcinoma
How can you distinguish Paget’s disease of the nipple from nipple eczema
Paget’s disease has a clear boundary. Eczema does not. Paget’s disease is usually bilateral
Risk factors for breast cancer
Early menarcheLate menopauseCOCPSmokingFamily historyParityHRT
What causes acromegally?
Pituitary adenomaGHInsulin-like growth factor
Skin tethering in the breast is due to what structure?
Ligament of Astley Cooper
Non facial symptoms of acromegaly
HypertensionDiabetesOACardiomyopathy Colorectal cancerCarpal tunnelSpade shaped handsSweaty, boggy hands
Medical management of acromegaly
Octreotide Bromocryptine
Facial features of acromegaly
Large tongueLarge lips Large earsLarge nosePrognathism Prominent supra-orbital ridgeBitemporal hemianopia Wide spaced teeth
Features of a neuropathic ulcer
SmallPunched outWell circumscribedPainless
Complications of neuropathic ulcers?
Superficial infectionAbscess formationOsteomyelitis
Features of autonomic neuropathy in diabetes?
Postural hypotensionErectile dysfunctionGastroparesisUrinary retentionNocturnal diarrhoea
Features of A Charcots joint
(Neuropathic joint)Repeated unnoticed traumaAbnormal stresses –> cartilage, ligament, muscle and bone destructionGrossly deformed, unstable but painless joint
Earliest detectable sign of diabetic nephropathy
Microalbuminuria(Not detected on standard dipstick)
What is de Quervain’s thyroiditis
Inflammation of the thyroid gland secondary to a Self-limiting viral infection. Initial hyperthyroidism then Hypothyroid state followed by euthyroid 4-6 months later
Symptoms of de Quervain’s thyroiditis
Goitre, Tenderness - neck, jaw, earsPain worse on swallowing fever, flulike symptoms
What is Graves’ disease
AutoimmuneIgG immunoglobulins stimulate TSH receptors on thyroid –> T4 release
Features of graves Eye disease
Proptosis (Exophthalmus)OphthalmoplegiaDiplopiaPeriorbital oedemaConjunctival oedema Lid retraction
Symptoms of hyperthyroidism
Heat intolerance, weight loss, anxiety, Restlessnessdiarrhoea, tremor, palpitationsOligomenorrhoeaGoitreSweatingIncreased appetiteHair thinningMuscle weaknessFatigue
Causes of hyperthyroidism?
Graves’ diseaseToxic solitary adenomaDe quervains thyroiditis (Transient hyperthyroidism)Follicular carcinoma of the thyroidLithiumAmiodaroneOvarian teratoma
Management of hyperthyroidism
Beta-blockers for symptomatic controlCarbimazolePropylthiouracilRadio iodine
What is Hashimoto’s thyroiditis
Autoimmune disease where the thyroid becomes infiltrated by plasma cells and lymphocytes. Causes goitre and thyroid dysfunction. Often euthyroid at presentation or hypothyroid. (Minority hyperthyroid)Autoantibodies to thyroid peroxidase and thyroglobulin
What is sick euthyroid syndrome?
Abnormal thyroid function in the presence of systemic disease
Causes of hypokalaemia
DiarrhoeaVomitingConn’s syndrome Diuretic useExcessive sweatingBurns
Features of hypokalaemia
Muscle weaknessCrampsECG changes - flat/inverted T, U wave, st depression
Complications of thyroidectomy
> Bleeding.>Unilateral recurrent laryngeal nerve injury –> hoarse voice, dyspnoea>Bilateral Recurrent laryngeal nerve injury –> upper airway obstruction at extubation. Potentially life threatening. >Hypoparathyroidism –> hypocalcaemia >Hypothyroidism>Thyrotoxic storm >Infection: 1-2%
How is radio iodine therapy for hyperthyroidism carried out
Oral administration of radioactive iodine containing solutionAbsorbed from GIT and transported to thyroid + stored. Damages cells and reduces thyroxine secretion
Common side effect for radio iodine therapy for hyperthyroidism
Hypothyroidism May need thyroxine replacement
CI to radioiodine therapy for hyperthyroidism
pregnantbreast-feeding F must be advised not to get pregnant for at least four months.May worsen Graves’ eye disease
Why should thyroxine be started with caution in patients with CVD
Can cause angina, HF, arrhythmiaStart at 25microg (normally 100)
Management of DKA
Aggressive fluid rescusInsulin infusion in saline. 1mg/kg/hrAdd potassium to fluid once k+ <14 start adding 20% dextrose alongside fluid
Management of HHS (hyperglycaemic hyperosmolar state)
IV fluidsIV insulin Enoxaparin
Features of hypoglycaemia
DizzinessSweating HungerDrowsinessPalpitationsAnxiety
Management of hypoglycaemia
If awake - lucozade, gluco-gelIf drowsy / unconscious - 75-80ml 20% dextrose IV or 150-160ml 10% dextrose.Or 1mg IM glucagon
What happens to a patients insulin requirement during illness
Increases
What are the most common type of thyroid tumours
Papillary adenocarcinoma (70%)Follicular carincomas (20%) Both most common in adolescence/young adultPresent as single thyroid nodule
Why do patients with a history of papillary or follicular thyroid carcinoma take lifelong thyroxine
As these carcinomas may be TSH dependent. Lifelong thyroxine acts to suppress endogenous TSH production + reduce recurrence risk
Management of papillary or follicular thyroid carcinoma
Total thyroidectomy
What is reidels thyroiditis
Idiopathic fibrosis of the thyroid gland Slow growing goitreFirm and irregular Can cause compressive symptoms - dysphagia, stridor, laryngeal nerve palsy
What is Hashimoto’s thyroiditis
Autoimmune thyroid conditionMost commonly affects womenDiffusely enlarged rubbery goitre Euthyroid then hypothyroid Autoantibodies to thyroid peroxidase
Treatment of Hashimoto’s thyroiditis
Thyroxine
In who is multi-nodular goitre most common
Middle aged F
Presentation of multi-nodular goitre
Unsightly goitreDysphagia 1 nodule may become an autonomous thyroxine secreting adenoma = toxic multi-nodular goitre –> AF, palpitations
Treatment of multi-nodular goitre
Radio-iodine or thyroidectomyAnti thyroid medications have little effect
What patients get anaplastic thyroid carcinomas
Elderly
Presentation of anaplastic thyroid carcinomas
Acute presentationAggressiveHard, symmetrical, rapidly enlarging goitreSpreads to LN and local structures
Treatment of anaplastic thyroid carcinomas
None - most die within 1 yearPalliative radiotherapy Debulking surgery
What causes conn’s syndrome
Aldosterone secreting tumour within the adrenal cortex
Presentation of conn’s syndrome
Prolonged non-specific illnessPolyuriaPolydipsia Fluid retention, hypervolaemia, hypertension
What causes hypernatraemia and hypokalaemia with normal renal function
conn’s syndrome
How can you confirm the diagnosis of conn’s syndrome
Raised plasma aldosterone Low plasma renin
Treatment of conn’s syndrome
Excision of the aldosterone secreting tumour And spironolactone (aldosterone antagonist)
What does a phaeochromocytoma release
Catecholamines > Adrenaline > Noradrenaline > Dopamine
Diagnosis of phaeochromocytoma
24 hour Urine collectionDemonstrates excess catecholamine degradation products = vanillylmandelic acidCT
Management of phaeochromocytoma
Surgical excisionUnder alpha and beta blockade to protect against potential excessive catecholamine release
In a symptomatic patient what test is considered diagnostic of DM
Single fasting blood glucose >7 mmol/LOrRandom blood glucose >11 mmol/L
In an asymptomatic patient what is considered diagnostic of DM
2 separate occasions of: - fasting blood glucose >7 mmol/LOr - Random blood glucose >11 mmol/L
What is the diagnostic criteria for impaired glucose tolerance
Fasting blood glucose <7 mmol/LAnd oral glucose tolerance test - 7.8 - 11.1 mmol/L 2 hours after 75g glucose bolus
What conditions may phaeochromocytoma Be associated with
NeurofibromatosisMultiple endocrine neoplasiaVon Hippel-Lindau
Best investigation for Addison’s disease
Short synacthen test
How is the short synacthen test done
Plasma cortisol levels measured before and 30 minutes after administration of a single IM dose of ACTH. Normal = rise in cortisolAdrenal insufficiency = no rise in cortisol
What hormone is released from small-cell lung carcinomas
ACTH
Symptoms of congenital adrenal hyperplasia
Precocious puberty (in girls)Accelerated growthAmbiguous genitalia (in girls)ClitoromegallyVirilisation
Inheritance pattern of congenital adrenal hyperplasia
Autosomal recessive
What hormones does congenital adrenal hyperplasia affect and how
Deficiency of enzyme 21-hydroxylaseEnzyme Required to synthesise mineralocorticoids and glucocorticoids but not adrenal androgens. Low steroid hormones means no feedback on anterior pituitary causing increased ACTH release ACTH causes increased secretion of androgens
Diagnostic test for congenital adrenal hyperplasia
Raised concentration of precursor 17-hydroxyprogesterone
Treatment of congenital adrenal hyperplasia
Hydrocortisone Fludrocortisone To replace steroid deficiency
What are carinoid tumours?
Tumours of enterochromaffin cells of GI tractCommonly of appendix, terminal ileum, rectumThey secrete serotonin which is carried in the portal system to the liver and broken down. But metastasis in the liver - secretes into blood stream
Diagnosis of carcinoid syndrome
24hr union urinary 5-hydroxindole acetic acid(Breakdown product of serotonin)
Management of carcinoid syndrome
Resection of tumourSymptomatic tx with octreotide (inhibits serotonin release)
Causes of parotid gland swelling
Viral parotitis - mumps (bilateral in 90%).Stone in salivary duct.Benign and malignant tumours.Sjögren’s syndrome.Sarcoidosis Acute and chronic bacterial parotitis.Wegener’s granulomatosis.HIV-related lymphocytic infiltration.
Causative organisms in salivary gland infection
Mumps = most common - bilateral swelling of the parotid glands (other salivary glands affected in 10%. Other viruses = Coxsackie virus, parainfluenza, influenza A, parvovirus B19, herpes.Bacterial infection occurs usually in debilitated or dehydrated patients - ascends from the oral cavity -most frequent = Staphylococcus aureus.
What is Spontaneous Atrophic Hypothyroidism
primary hypothyroidism increases in incidence with age autoimmune. destructive lymphoid infiltration of the thyroid leading to fibrosis and atrophy.
Hyperthyroidism plus a thyroid bruit suggests what
Graves’ disease
Presentation of myxoedema coma
Severe hypothyroidismReduced consciousness HypothermiaBrachycardiaHypoglycaemia
Presentation of thyrotoxic crisis
FeverTachycardiaAgitationAFHFCan be precipitated by stress or infection
Tumours of Multiple endocrine neoplasia type 1
Gastrinoma (pancreatic tumour)ProlactinomaParathyroid adeonoma Pituitary adenomaPancreatic islet cell tumour
Tumours of Multiple endocrine neoplasia type 2
parathyroid adenomaMedullary thyroid carcinomaPheochromocytoma
Tumours of Multiple endocrine neoplasia type 3
Tumours of mem type 2 (parathyroid, medullary thyroid, phaeochromocytoma)AND Mucosal neuroma of the GI tractMarfanoid phenotype
What is diabetes insupidus
Lack of ADH secretion Or a peripheral resistance to ADH Causes increased urine production - v diluteDehydration
What Are the 2 types of diabetes insipidus
NephrogenicCranial
How do you distinguish nephrogenic and cranial diabetes insipidus
Do water deprivation test then give desmopressinCranial DI = lack of ADH production. - so desmoprin causes urine concentration. Nephrogenic DI = resistance to ADH - so desmopressin has no effect
How do you diagnose diabetes insipidus
Water deprivation test - measure urine osmolarity hourly + weight. Normal patients concentrate their urine. In DI large volumes of dilute urine continue to be produced
Treatment of diabetes insipidus
Cranial DI - desmopressinNephrogenic DI - good fluid management, NSAIDs and thiazide diuretics helps reduce urine output
Presentation of bilateral renal agenesis
Incompatible with life - still birth or early neonatal deathMother has oligohydramnios - as foetus doesn’t produce urine
Symptoms of hyperkalaemia
LethargyPolyuria PolydipsiaPeptic ulcer Stone formationDepression Cardiac arrest (v. High)
What does parathyroid hormone do?
Increases serum calcium concentration Promotes bone resorption, renal phosphate excretion and vitamin D synthesis
What is primary hyperparathyroidism
Parathyroid gland secretes too much PTH Usually parathyroid adenoma
What is pseudo-hypoparathyroidism
Autosomal dominant End organ resistance to PTHLearning difficulties Short statureShort 4th and 5th metacarpals
Complications of thyroid surgery
BleedingThyroid crisisHypoparathyroidism –> hypocalcaemia Recurrent laryngeal nerve damage HypothyroidismRecurrence of hyperthyroidism
What is the blood supply to the thyroid
Dual blood supply- superior thyroid artery (external carotid)- inferior thyroid artery (subclavian)
What is pembertons test for a retrosternal goitre
Raise pt arms above head and hold there. Elevates the clavicles and raises the thoracic inlet Causes pink face due to temporary SVC obstruction = Pembertons sign
What is nelson’s syndrome
Follows bilateral adrenalectomy when a patient has Cushing’s disease and the tumour cannot be located. The removal of negative feedback allows the tumour to grow unchecked. Causes skin hyperpigmentation
In what patients are selective aromatase inhibitors used (e.g. Arimidex)
Post menopausal women with oestrogen sensitive breast cancer. Act to block peripheral conversion of oestrogens.
Causes of hirsutism
Idiopathic PCOSadrenal hyperplasia Cushing’s
Causes of palmar erythema
Chronic liver diseaseHyperthyroidism RAPregnancyPolycythaemia
What is pickwickian syndrome
Obesity hyperventilation syndrome
What is an insulinoma
Tumour of pancreatic beta cells Over secrete insulin
Symptoms of an insulinoma
Hypoglycaemia Weak SweatingConfusionHunger Diarrhoea
What is whipples triad of symptoms for insulinoma
Attacks induced by starvationHypoglycaemia during the attackSymptoms relieved by eating
What is a VIPoma
Pancreatic islet cell tumourProduces vasoactive intestinal polypeptideStimulates secretion of water and electrolytes
What is a glucagonoma
Pancreatic alpha cell tumour Secretes glucagonCauses hyperglycaemia
Symptoms of a gastrinoma
Pancreatic G cell tumourCauses peptic ulcerationDiarrhoea
What is Zollinger-Ellison syndrome
Features resulting from gastrinoma over producing gastrin
Symptoms of a pituitary adenoma
HeadacheBi-temporal hemianopia Amenorrhoea (low LH and FSH)Excess of certain hormones e.g. ACTH / GH / prolactin
Symptoms of a craniophyaringioma
Insidious Some of:- Hypothyroidism - adrenal failure - diabetes insipidus - decreased libido- erectile dysfunction - amenorrhoea Headaches.Bitemporal inferior quadrantanopia / bitemporal hemianopia dementia hydrocephalus - headache, papilloedema, visual impairment.
What is McCune Albright syndrome
At least two features of the triad of:- Polyostotic fibrous dysplasia.- Cafe au lait skin pigmentation.- Autonomous endocrine hyperfunction (precocious puberty / thyrotoxicosis / pituitary gigantism / Cushing’s syndrome)
When should patients with diabetes be scheduled for surgery
Early in the dayIdeally 1st on list
How long are diabetic patients kept nil by mouth for before surgery
6 hours for solids2 hours for clear fluids (Same as other patients)
When do patients with diabetes need admitting for surgery
Can be say case if well controlled - omit long acting hypoglycaemic or insulin the night before. If poorly controlled - admit night before and start sliding scale
In whom is hyperosmolar hyperglycaemic state most common
Elderly
What is bronzed diabetes
New diagnosis of diabetes in haemochromatosis+ hypogonadism+ arthralgia+ deranged LFTs+ pigmentation
What is necrobiosis lipoidica
Painless rash Central yellowish lipid-like coreSurrounding brown/purple peripheries Ulceration may occur
Tx of necrobiosis lipoidica
PUVA improved glycemic control
SE of metformin
N+VDiarrhoea Abdo painLactic acidosis
1st investigation in a DM patient with 1st episode of proteinuria on dipstick
Albumin : creatinine ratioMicrobiology - infection is a treatable cause
