MRCP 2 Flashcards
What is abetalipoproteinaemia?
rare autosomal recessive disorder caused by a mutation in the microsomal triglyceride transfer protein.
This results in deficiencies in the apolipoproteins B-48 and B-100.
What are the features of abetalipoproteinaemia?
failure to thrive + developmental delay
steatorrhoea
retinitis pigmentosa
cerebellar signs
deep tendon reflexes are absent
acanthocytosis
hypocholesterolaemia
What is the most common reason for acromegaly?
Pituitary adenoma
Excess GH
A minority of cases are caused by ectopic GHRH or GH production by tumours e.g. pancreatic.
What are the features of acromegaly?
coarse facial appearance, spade-like hands, increase in shoe size
large tongue,
prognathism - profusion of upper jaw
interdental spaces
excessive sweating and oily skin: caused by sweat gland hypertrophy
features of pituitary tumour: hypopituitarism, headaches, bitemporal hemianopia
raised prolactin in 1/3 of cases → galactorrhoea
6% of patients have MEN-1
What conditions are associated with MEN1 ?
MEN-1
What are complications of acromegaly?
hypertension
diabetes (>10%)
cardiomyopathy
colorectal cancer
What is the test of acromegaly?
serum insulin growth factor 1
Previously oral glucose tolerance test with serial growth hormone measurements
If insulin growth factor 1 is equivocal, what test should be done?
Oral glucose tolerance
What is the normal response to growth hormone in oral glucose tolerance?
in normal patients GH is suppressed to < 2 mu/L with hyperglycaemia
in acromegaly there is no suppression of GH
may also demonstrate impaired glucose tolerance which is associated with acromegaly
First line treatment of acromegaly?
Transpehnoidal surgery
When should surgery be used in acromegaly?
If surgery cannot be pursued or is unsuccessful
What medication should be used in acromegaly ?
- somatostatin analogue
- Pegvisomant
- Dopamine antagonists
Mechanism of somatostatin analogue?
Directly inhibits the release of growth hormone
Mechanism of pegvisomant in acromegaly?
GH receptor antagonist - prevents dimerization of the GH receptor
- Does not reduce tumour volume, therefore needs surgery still
Mechanism of dopamine antagonist?
e.g. Bromocriptine
first effective medical treatment for acromegaly, however now superseded by somatostatin analogues
Features of Addisons disease?
lethargy, weakness, anorexia, nausea & vomiting, weight loss, ‘salt-craving’
hyperpigmentation (especially palmar creases)*, vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia
hyponatraemia and hyperkalaemia may be seen
crisis: collapse, shock, pyrexia
Features of Addison’s crisis?
crisis: collapse, shock, pyrexia
Causes of hypoadrenalism?
Primary causes
- tuberculosis
- metastases (e.g. bronchial carcinoma)
- meningococcal septicaemia (Waterhouse-Friderichsen syndrome)
- HIV
- antiphospholipid syndrome
Secondary causes
- pituitary disorders (e.g. tumours, irradiation, infiltration)
Primary and secondary hypoadrenalism - which one has hypopigmentation?
Primary hypoadrenalism only
Secondary hypoadrenalism is not associated with hypopigmentation
What is the management for Addison’s disease?
combination of:
hydrocortisone: usually given in 2 or 3 divided doses. Patients typically require 20-30 mg per day, with the majority given in the first half of the day
fludrocortisone
What should be given to patients to prevent adrenal crisis?
hydrocortisone injections
Illness in Addisons, what should be done to the steroids?
glucocorticoid dose should be doubled, with the fludrocortisone dose staying the same
Management of addisonian crisis?
hydrocortisone 100 mg im or iv
1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic
continue hydrocortisone 6 hourly until the patient is stable.
fludrocortisone should begin after 24 hours and be reduced to maintenance over 3-4 day
Causes of raised ALP?
liver: cholestasis, hepatitis, fatty liver, neoplasia
Paget’s
osteomalacia
bone metastases
hyperparathyroidism
renal failure
physiological: pregnancy, growing children, healing fractures
Raised ALP + Calcium raised?
Bone metastases
Hyperparathyroidism
Raised ALP + low calcium?
Osteomalacia
Renal failure
Inheritance of androgen insensitivity?
X-linked recessive condition
Phenotype and genotype of androgen insensitivity syndrome?
male children (46XY) to have a female phenotype
Feature of androgen insensitivity syndrome?
‘primary amenorrhoea’
little or no axillary and pubic hair
undescended testes causing groin swellings
breast development may occur as a result of the conversion of testosterone to oestradiol
Diagnosis of androgen insensitivity syndrome?
- buccal genotype
2.after puberty, testosterone concentrations are in the high-normal to slightly elevated reference range for postpubertal boys
Autoimmune polyendocrinopathy syndrome types?
Type 1: Multiple Endocrine Deficiency Autoimmune Candidiasis
Type 2: Schmidt syndrome
Features of type 2 autoimmune polyendocrinopathy syndrome?
Addison’s disease
+
Type 1 diabetes mellitus
+
Autoimmune thyroid disease
Features of type 1 autoimmune polyendocrinopathy syndrome?
Features of APS type 1 (2 out of 3 needed)
chronic mucocutaneous candidiasis (typically first feature as young child)
Addison’s disease
primary hypoparathyroidism
Genotype of Features of type 1 autoimmune polyendocrinopathy syndrome?
autosomal recessive disorder caused by mutation of AIRE1 gene on chromosome 21
Barter syndrome?
Normotensive
Hypokalaemia
Polyurea and polydipsia
What is the mechanism of Bartter syndrome?
severe hypokalaemia due to defective chloride absorption at the Na+ K+ 2Cl- cotransporter (NKCC2) in the ascending loop of Henle
What is the inheritance of barter’s syndrome?
Autosomal recessive
Mechanism of carbimazole?
blocks thyroid peroxidase from coupling and iodinating the tyrosine residues on thyroglobulin → reducing thyroid hormone production
in contrast propylthiouracil as well as this central mechanism of action also has a peripheral action by inhibiting 5’-deiodinase which reduces peripheral conversion of T4 to T3
What is the side effect of carbimazole?
agranulocytosis
crosses the placenta, but may be used in low doses during pregnancy
HPV viruses types related to cervical cancer?
serotypes 16,18 & 33
Risk factors of cervical cancer?
HPV
smoking
human immunodeficiency virus
early first intercourse, many sexual partners
high parity
lower socioeconomic status
combined oral contraceptive pill*
Causes of congenital adrenal hyperplasia?
21-hydroxylase deficiency (90%)
11-beta hydroxylase deficiency (5%)
17-hydroxylase deficiency (very rare)
Test for congenital adrenal hyperplasia?
ACTH stimulation
Features of 21-hydroxylase deficiency features
congenital adrenal hyperplasia?
virilisation of female genitalia
precocious puberty in males
60-70% of patients have a salt-losing crisis at 1-3 wks of age
Features of 11-beta hydroxylase deficiency features
congenital adrenal hyperplasia?
virilisation of female genitalia
precocious puberty in males
hypertension
hypokalaemia
Features of17-hydroxylase deficiency features
congenital adrenal hyperplasia?
non-virilising in females
inter-sex in boys
hypertension
Features of congenital hypothyroidism? (cretinism)
prolonged neonatal jaundice
delayed mental & physical milestones
short stature
puffy face, macroglossia
hypotonia
How is congenital adrenal hyperplasia tested?
Children are screened at 5-7 days using the heel prick test
Minimal glucocorticoid activity, very high mineralocorticoid activity,
Fludrocortisone
Glucocorticoid activity, high mineralocorticoid activity,
Hydrocortisone
Predominant glucocorticoid activity, low mineralocorticoid activity
Prednisolone
Very high glucocorticoid activity, minimal mineralocorticoid activity
Dexamethasone
Betmethasone
Cushing’s: ACTH dependent causes?
Cushing’s disease (80%): pituitary tumour secreting ACTH producing adrenal hyperplasia
Ectopic ACTH production (5-10%): e.g. small cell lung cancer is the most common causes
Cushing’s: ACTH independent causes?
iatrogenic: steroids
adrenal adenoma (5-10%)
adrenal carcinoma (rare)
Carney complex: syndrome including cardiac myxoma
micronodular adrenal dysplasia (very rare)
What is pseudo cushings?
mimics Cushing’s
often due to alcohol excess or severe depression
causes false positive dexamethasone suppression test or 24 hr urinary free cortisol
insulin stress test may be used to differentiate
Biochemisty in bushings disease?
A hypokalaemic metabolic alkalosis may be seen, along with impaired glucose tolerance.
Ectopic ACTH secretion (e.g. secondary to small cell lung cancer) is characteristically associated with very low potassium levels.
Most common tests for cushing disease?
- Overnight dexamethasone suppression test
(sensitive) - 24 hr urinary free cortisol
High dose dexamethasone tests:
Cortisol not suppressed + ACTH suppressed?
Cushing’s syndrome due to other causes (e.g. adrenal adenomas)
High dose dexamethasone tests:
Cortisol surpassed + ACTH suppressed?
Cushing’s disease (i.e. pituitary adenoma → ACTH secretion)
High dose dexamethasone tests:
Cortisol not supressed + ACTH not supressed?
Ectopic ACTH syndrome
How do you differentiate between cushings and pseudocushings?
Insulin stress test
Criteria for diabetes if symptomatic?
fasting glucose greater than or equal to 7.0 mmol/l
random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
Criteria for diabetes if asymptomatic?
HbA1c of greater than or equal to 48 mmol/mol (6.5%) is diagnostic of diabetes mellitus
a HbAlc value of less than 48 mmol/mol (6.5%) does not exclude diabetes (i.e. it is not as sensitive as fasting samples for detecting diabetes)
IF ASSYMPTOMATIC NEEDS TO REPEAT THE TEST
Conditions where HbA1c should not be used?
haemoglobinopathies
haemolytic anaemia
untreated iron deficiency anaemia
suspected gestational diabetes
children
HIV
chronic kidney disease
Positive test result for impaired fasting glucose?
A fasting glucose greater than or equal to 6.1 but less than 7.0 mmol/l implies impaired fasting glucose (IFG)
Criteria for oral glucose tolerance test ?
Impaired glucose tolerance (IGT) is defined as fasting plasma glucose less than 7.0 mmol/l and OGTT 2-hour value greater than or equal to 7.8 mmol/l but less than 11.1 mmol/l
Causes of primary hypothyroidism?
Hashimotos
Subacute thyroiditis (de Quervain’s)
Riedel thyroiditis
After thyroidectomy or radioiodine treatment
Drug therapy (e.g. lithium, amiodarone or anti-thyroid drugs such as carbimazole)
Dietary iodine deficiency
Causes of secondary hypothyroidism?
Down’s syndrome
Turner’s syndrome
coeliac disease
What should you aim HbA1c in diabetes?
48
What blood glucose targets should be in place for T1DM?
5-7 mmol/l on waking and
4-7 mmol/l before meals at other times of the day
What choice of insulin regimen should patients be given?
Basal bolus only
Twice daily insulin detemir
Once daily insulin glargine
Target for HbA1c on type 2 diabetes with drugs that cause hypoglycaemia?
53
SGLT-2 inhibitors should also be given in addition to metformin when?
the patient has a high risk of developing cardiovascular disease (CVD, e.g. QRISK ≥ 10%)
the patient has established CVD
the patient has chronic heart failure
If standard release metformin is not tolerated, what should be used?
Modified release metformin
What should be used if metformin is contraindicated?
If CVS disease:
- SGLT2 inhibitors
No CVS disease:
DPP‑4 inhibitor or pioglitazone or a sulfonylurea
SGLT-2 may be used if certain NICE criteria are met
Type of insulins needed in basal bolus injection?
offer rapid‑acting insulin analogues injected before meals
twice‑daily insulin detemir is the regime of choice.
Second line therapy for T2DM?
Dual therapy - add one of the following:
metformin + DPP-4 inhibitor
metformin + pioglitazone
metformin + sulfonylurea
metformin + SGLT-2 inhibitor (if NICE criteria met)
Third line therapy T2DM?
metformin + DPP-4 inhibitor + sulfonylurea
metformin + pioglitazone + sulfonylurea
metformin + (pioglitazone or sulfonylurea or DPP-4 inhibitor) + SGLT-2 if certain NICE criteria are met
insulin-based treatment
Should T2Dm patients get statins?
Primary prevention:
- if QRISK > 10
- egFR > 60
Give atorvastatin 20 mg
Secondary prevention:
- 80 mg atorvastatin
Blood pressure cut off for T2DM?
Clinic first, home second
Age < 80 years 140/90 mmHg 135/85 mmHg
Age > 80 years 150/90 mmHg 145/85 mmHg
Diagnostic criteria for DKA?
Key points
glucose > 11 mmol/l or known diabetes mellitus
pH < 7.3
bicarbonate < 15 mmol/l
ketones > 3 mmol/l or urine ketones ++ on dipstick
Management of DKA?
fluid replacement
most patients with DKA are deplete around 5-8 litres
isotonic saline is used initially, even if the patient is severely acidotic
please see an example fluid regime below.
insulin
an intravenous infusion should be started at 0.1 unit/kg/hour
once blood glucose is < 14 mmol/l an infusion of 10% dextrose should be started at 125 mls/hr in addition to the 0.9% sodium chloride regime
correction of electrolyte disturbance
serum potassium is often high on admission despite total body potassium being low
this often falls quickly following treatment with insulin resulting in hypokalaemia
potassium may therefore need to be added to the replacement fluids
if the rate of potassium infusion is greater than 20 mmol/hour then cardiac monitoring may be required
long-acting insulin should be continued, short-acting insulin should be stopped
Resolution of DKA?
pH >7.3 and
blood ketones < 0.6 mmol/L and
bicarbonate > 15.0mmol/L
Complications of DKA?
gastric stasis
thromboembolism
arrhythmias secondary to hyperkalaemia/iatrogenic hypokalaemia
iatrogenic due to incorrect fluid therapy: cerebral oedema*, hypokalaemia, hypoglycaemia
acute respiratory distress syndrome
acute kidney injury
Management of neuropathy in diabetes?
First line: amitriptyline, duloxetine, gabapentin or pregabalin
treatment does not work try one of the other 3 drug
Rescue therapy: tramadol
Topical capsaicin
How should gastroparesis be managed in diabetes?
metoclopramide, domperidone or erythromycin (prokinetic agents)
Features of gastroparesis?
Bloating
Erratic blood glucose control
Vomiting
Phenotype of androgen insensitivity syndrome? Genotype?
46 XY
Female phenotype
Rudimentary vagina and testes present but no uterus.
Testosterone, oestrogen and LH levels are elevated
Phenotype 5 alpha reductase ? Genotype?
46 XY
Autosomal recessive condition. Results in the inability of males to convert testosterone to dihydrotestosterone (DHT)
ambiguous genitalia in the newborn period. Hypospadias is common. Virilization at puberty.
Cause of male pseudohaeaphroditism?
Individual has testes but external genitalia are female or ambiguous. may be secondary to androgen insensitivity syndrome
Genotype 46 XY
Cause of female pseudohaemaphrotism?
Individual has ovaries but external genitalia are male (virilized) or ambiguous. May be secondary to congenital adrenal hyperplasia
46 XX
High LH + Low testosterone?
Klinfelters (primary hypogonadism)
Low LH + Low testosterone?
Hypogonadotrophic hypogonadism
(Kallman’s syndrome)
High LH + High/Normal Testosterone?
Androgen insensitivity syndrome
Low LH + High testosterone?
Testosterone secreting tumour
Phenotype of klinfelters?
often taller than average
lack of secondary sexual characteristics
small, firm testes
infertile
gynaecomastia - increased incidence of breast cancer
elevated gonadotrophin levels
Gentyoe of klinfelters?
47 XXY
Phenotype of kallman’s syndrome?
‘delayed puberty’
hypogonadism, cryptorchidism
anosmia
sex hormone levels are low
LH, FSH levels are inappropriately low/normal
patients are typically of normal or above average height
DVLA driver requirements?
- there has not been any severe hypoglycaemic event in the previous 12 months
the driver has full hypoglycaemic awareness
the driver must show adequate control of the condition by regular blood glucose monitoring*, at least twice daily and at times relevant to driving
the driver must demonstrate an understanding of the risks of hypoglycaemia
here are no other debarring complications of diabetes
Risk factors for endometiral cancer?
nulliparity
early menarche
late menopause
unopposed oestrogen. The addition of a progestogen to oestrogen reduces this risk (e.g. In HRT)
Metabolic syndrome:
- obesity
- diabetes mellitus
- polycystic ovarian syndrome
tamoxifen
hereditary non-polyposis colorectal carcinoma
Protective factors for endometrial cancer?
Smoking
Multiparity
Combined contraceptive pill
First line investigation of endometiral cancer?
Transvaginal ultrasound
<4mm has a strong negative predictive value
Definitive investigation for endometrial cancer?
Hysterostomy and biopsy
Management of local endometiral cancer?
Hysterectomy + bilateral sapinoophrectomy
High risk patients should recieve radiotherapy
Treatment of endometiral cancer in frail elderly women?
Progesterne therapy
What is the pathophysiology behind familial benign hypocalciuric hypercalcaemia?
Defect in the calcium-sensing receptor
Recessive
What levels of calcium would be expected in familial benign hypocalciuric hypercalcaemia?
Normal PTH
High Calcium
Screen test for gestational diabetes?
oral glucose tolerance test (OGTT) is the test of choice
fasting glucose is >= 5.6 mmol/L
2-hour glucose is >= 7.8 mmol/L
What is the diagnostic criteria for gestational diabetes ?
fasting glucose is >= 5.6 mmol/L
2-hour glucose is >= 7.8 mmol/L
Management of gestational diabetes? Fasting glucose is < 7
if the fasting plasma glucose level is < 7 mmol/l a trial of diet and exercise should be offered
if glucose targets are not met within 1-2 weeks of altering diet/exercise metformin should be started
if glucose targets are still not met insulin should be added to diet/exercise/metformin
gestational diabetes is treated with short-acting, not long-acting, insulin
Management of gestational diabetes? - Fasting glucose > 7?
Start on insulin
Management of women who are already diabetic and become pregnant?
weight loss for women with BMI of > 27 kg/m^2
stop oral hypoglycaemic agents, apart from metformin, and commence insulin
folic acid 5 mg/day from pre-conception to 12 weeks gestation
detailed anomaly scan at 20 weeks including four-chamber view of the heart and outflow tracts
tight glycaemic control reduces complication rates
treat retinopathy as can worsen during pregnancy
What diabetic complication can worsen in pregnancy?
Retinopathy
What is the pathophysiology of gieltman syndrome?
Distal convoluted tubule
thiazide-sensitive Na+ Cl- transporter
Features of Gieltman?
Normotensive
Hypokalaemia
Hypocalcaemia
Hypomagnesaemia
Metabolic alkalosis
(Like taking too much thiazide)
Where is a glucagonoma always found ?
In the pancreas
arise from the alpha cells of the pancreas.
Features of glucagonoma?
Necrolytic migratory erythema - red blistering
Venous thromboembolism
Diagnosis of glucagonoma?
Glucagon elevated
CT scan
Management of glucagonoma?
Surgical resection
Octerotide
Features of Graves disease ?
eye signs (30% of patients)
exophthalmos
ophthalmoplegia
pretibial myxoedema
thyroid acropachy, a triad of:
digital clubbing
soft tissue swelling of the hands and feet
periosteal new bone formation
Features of thyroid acropachy?
digital clubbing
soft tissue swelling of the hands and feet
periosteal new bone formation
What antibodies are seen in graves disease ?
TSH receptor stimulating antibodies (90%)
anti-thyroid peroxidase antibodies (75%)
In graves disease what is seen in scintography?
Increased generalised uptake
Initial treatment of Graves disease ?
Propanolol - for adrenergic effects
Carbimazole 40 mg
typically continued for 12-18 months
In graves disease who should be managed with radio-idodine therapy?
Patients who relapse therapy after carbimazole
Contraindication to radio-iodine treatment?
Thyroid eye disease
Age < 16
Causes of gynaecomastia?
physiological: normal in puberty
syndromes with androgen deficiency: Kallman’s, Klinefelter’s
testicular failure: e.g. mumps
liver disease
testicular cancer e.g. seminoma secreting hCG
ectopic tumour secretion
hyperthyroidism
haemodialysis
Drug causes of gynaecomastia?
spironolactone (most common drug cause)
cimetidine
digoxin
cannabis
finasteride
GnRH agonists e.g. goserelin, buserelin
oestrogens, anabolic steroids
Features of hashimotos thyroiditis?
features of hypothyroidism
goitre: firm, non-tender
anti-thyroid peroxidase (TPO) and also anti-thyroglobulin (Tg) antibodies
May have transient hyperthyroidism
What haematological malignancy is assocated with hashimotos?
MALT lymphoma
What is hungry bone syndrome?
Occurs following parathyroidectomy
Rapid decrease in PTH casues decreased osteclast activity
Rapid remineralisation of bone
Bone pains noted + systemic hypocalcaemia
Most common causes of hypercalaemia?
- Primary hyperparathyroidism
- Malignancy - squamous cell carcinoma - secrete PTH
Rarer causes of hypercalcaemia
sarcoidosis
other causes of granulomas may lead to hypercalcaemia e.g. tuberculosis and histoplasmosis
vitamin D intoxication
acromegaly
thyrotoxicosis
Milk-alkali syndrome
thiazides
calcium-containing antacids
dehydration
Addison’s disease
Paget’s disease of the bone
Management of hypercalcaemia?
- Saline 3/4 L per day
Other options include:
calcitonin - quicker effect than bisphosphonates
steroids in sarcoidosis
Management of hyperemesis gravivarum?
Frist line:
antihistamines: oral cyclizine or promethazine
phenothiazines: oral prochlorperazine or chlorpromazine
Second line: Oral ondansetron ( discuss risk of cleft palet)
Oral metoclopramide / domperidone ( extrapyramidal side effects)
ECG changes of hyperkalaemia ?
tall-tented T waves, small P waves, widened QRS leading to a sinusoidal pattern and asystole
Causes of hyperkalaemia?
acute kidney injury
metabolic acidosis
Addison’s disease
rhabdomyolysis
massive blood transfusion
Drugs that cause hyperkalaemia?
drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin**
When should statin be monitored post commencing?
3 months
Causes of hypernatraemia?
dehydration
osmotic diuresis e.g. hyperosmolar non-ketotic diabetic coma
diabetes insipidus
excess IV saline
Pathophysiology of HHS?
Pathophysiology
hyperglycaemia → ↑ serum osmolality → osmotic diuresis → severe volume depletion
Diagnostic criteria of HHS?
hypovolaemia
marked hyperglycaemia (>30 mmol/L)
significantly raised serum osmolarity (> 320 mosmol/kg)
can be calculated by: 2 * Na+ + glucose + urea
no significant hyperketonaemia (<3 mmol/L)
no significant acidosis (bicarbonate > 15 mmol/l or pH > 7.3 – acidosis can occur due to lactic acidosis or renal impairment)