Endocrinology 3 Flashcards
What is the triad of thyroid acropachy?
Clubbing
Soft tissue swelling of hands and feet
Periosteal new bone formation
Autoantibodies in Grave’s disease (2)
Hashimotos (2)
TSH receptor stimulating antibodies
Anti-thyroid peroxidase antibodies
Anti-TPO and anti-thyroglobulin (Tg)
What do you see on scintigraphy in Grave’s
increased uptake of radioactive iodine
When would you start carbimazole and how?
If propranolol hasn’t worked for symptom control.
Start at 40mg and reduce gradually - continued for 12-18 months.
SE of carbimazole (1)
agranulocytosis
What is the block and replace regime for Grave’s mx
When should it be used?
Carbimazole 40mg, thyroxine when euthyroid - rx lasts 6-9 months
Pregnancy
Contraindications to radioiodine treatment (3)
Pregnancy and avoid for 4-6 months after treatment
<16yo
Thyroid eye disesae
Hashimotos associations (4)
Vitiligo
Coeliac
MALT lymphoma
T1DM
Mx hypothyroidism
Following a change in medication when should the TFTs be repeated
Start at 50-100mcg OD
Unless:
Cardiac disease OR
Severe hypo OR
>50yo
Start at 25mcg
8-12 weeks
In pregnancy in hypothyroidism how should the thyroxine be changed?
Increase by 25-50mcg
SE thyroxine (4)
reduce bone mineral density
hyperthyroid
AF
worsening of angina
Which two drugs interact with thyroxine?
How to prevent this?
Iron
Calcium carbonate
Take 4 hours apart
Secondary causes of hypothyroidism (3)
Down’s
Turners
Coeliacs
How often should you test TSH in pregnancy?
Each trimester and 6-8 weeks post partum
Mx thyrotoxicosis in pregnancy and why
Propylthiouracil if first trimester, switched to carbimazole second and third
Carbimazole can cause congential abnormalities
Propylthiouracil can cause severe hepatic injury
Why should maternal free thyroxine levels be kept in the upper third of the normal reference range?
to avoid fetal hypothyroidism
Most common type of pituitary adenoma
Prolactinoma
Classification of pituitary adenomas
Size:
Micro <1cm
Macro >1cm
Hormonal status
Features of prolactinoma
Women (4)
Male (3)
Galactorrhoea
Infertility
Amenorrhea
Osteoporosis
Galactorrhoea
Loss of libido
Impotence
Dx of prolactinomas (1)
Mx (2)
MR
Dopamine agonist e.g cabergoline, bromocriptine
surgery - transpheroidal
Causes of raised prolactin (6)
prolactinoma
pregnancy
oestrogens
primary hypothyroidism
PCOS
acromegaly
Drug causes of raised prolactin (4)
Metoclopramide
Domperidone
Haloperidol
SSRIs
Features of primary hyperparathyroidism
Bones, stones, abdominal groans and psychic moans
polydipsia, polyuria
depression
anorexia, nausea, constipation
peptic ulceration
pancreatitis
bone pain/fracture
renal stones
Primary hyperparathyroidism
associations (2)
HTN
MEN I+II
Elderly female, unquenchable thirst =
primary hyperparathyroidism
Physiology of parathyroid gland
Role of PTH
How does it do this? (3)
What is the purpose of vit D?
Low calcium leads to increase in PTH
Role of PTH is to increase calcium levels
PTH causes:
1. Increased gut absorption
2. Increased reabsorption of calcium from the kidneys
3. Increased osteoclast activity, to break down bone to increase calcium levels
Vit D does the same as PTH, increase PTH leads to increase conversion of vit D into active form so it can help with above effects.
Explain primary hyperparathyroidism
Causes (1)
Mx
High PTH
High calcium
Low phosphate
Caused by parathyroid gland tumour
Mx surgery
Explain secondary hyperparathyroidism
Causes (2)
Mx
High PTH
Low (or normal) calcium
High phosphate
Caused by vit D deficiency or CKD
Mx treat deficiency or renal transplant
Explain tertiary hyperparathyroidism
Mx
High PTH
High calcium
Low phosphate
Secondary to hyperplasia of parathyroid gland due to secondary hyperparathyroidism after it has been corrected
Mx surgery
Characteristic XR finding for hyperparathyroidism
pepperpot skull
When would you consider conservative mx of primary hyperparathyroidism?
the calcium level is less than 0.25 mmol/L above the upper limit of normal AND the patient is > 50 years AND there is no evidence of end-organ damage
Medical management of primary hyperparathyroidism if pt not suitable for surgery
Cinacalcet - mimics calcium on tissues
Primary hyperaldosteronism
Conns
define:
bilat idiopathic adrenal hyperplasia is the cause in up to 70%
Conns is secondary to an adrenal tumour
Features Conns (4)
HTN
Hypernatramiea
Hypokalaemia - muscle weakness
Alkalosis
Primary hyperaldosteronism
Ix (3)
- Aldosterone/renin ratio
High aldosterone, low renin (due to low feedback system) - high resolution CT abdomen
- Adrenal vein sampling to differentiate between unilat and bilat sources
Primary hyperaldosteronism
Mx (2)
Adrenal adenoma - surgery
Bilateral adrenocortical hyperplasia - aldosterone antagonist e.g spiro
Pheochromocytoma associated with (3)
MEN II
Neurofibromatosis
von Hippel Lindau syndrome
Pheochromocytoma
Ix
24 hour urinary collection of metanephrines
Pheochromocytoma
Mx
Must be stabilised on which four medications
Surgery
Must be medically stabilised with an AB and BB phenoxybenzamine and propranolol
Prediabetes/ Impaired glucose regulation numbers
Fasting
HbA1c
Fasting BM 6.1-6.9 OR
HbA1c of 42-48 (6.0-6.4)
Mx of prediabetes (3)
Lifestyle modification
Yearly FU with bloods
Metformin in adults who are high risk
Obesity Mx (3)
Lifestyle factors
Medical - orlistat
Surgical
Orlistat criteria
BMI >=28 with associated RF
BMI >=30
Continued weight loss at 3 months
To be used for <1 year
Most common cancer in infants
Neuroblastoma
What is a neuroblastoma
Tumour from the neural crest tissue of the adrenal medulla and sympathetic nervous system
Neuroblastoma features (6)
abdominal mass
pallor
weight loss
bone pain
limp
hepatomegaly
MEN = multiple endocrine neoplasia
Type I, IIa, IIb
I 3Ps hyperPTH, pituitary, pancreas
MEN I = most common presentation hypercalcaemia
IIa 2Ps PTH, pheo
RET oncogene
IIb 1P pheo, marfans, neuromas
RET oncogene
medullar thyroid and pheo for both types of II
Common causes of hypercalcaemia (2)
- Primary hyperPTH
- Malignancy e.g myeloma
Other causes of hypercalcaemia (8)
Sarcoidosis
Vitamin D intoxication
Acromegaly
Thyrotoxicosis
Thiazides
Dehydration
Addison’s
Pagets
SVAT DAPT
Mx hypoglycaemia
- Oral gluc 10-20g OR glucogel PO/SC/IM
Hospital
As above but if unconscious then SC/IM glucogel
OR
IV 20% glucose
Hypoparathyroidism
Caused by
Low PTH, low calcium, high phosphate
Secondary to thyroid surgery
Hypoparathyroidism
Mx
Alfaclcidol
Features hypoparathyoidism (6)
Secondary to hypocalcaemia
Muscle twitching
Trousseau’s sign
Chvostek’s sign
Periooral parasthesia
Depression/ cataracts
Long QT
What is Trousseau’s sign
occlude brachial artery with a BP cuff, wrist flexes, thumb adducts
What is Chvostek’s sign
tapping over parotid causes facial muscles to twitch
PseudohypoPTH
What is it?
Biochem
target cells are insensitive to PTH
So low calcium, high phosphate but high PTH
Pseudopseudohypoparathyroidism
Biochem
Normal biochem
What is Kallman’s?
delayed puberty secondary to hypogonadotrophic hypogonadism
X linked recessive
A boy with lack of smell with delayed puberty =
Kallmans
Features of Kallmans (6)
Anosmia
Delayed puberty
Hypogonadism
Cryptorchidism (absence of one testicle)
LH and FSH low
Normal and above average height
What is Klinefelter’s karyotype
Features (6)
XXY
Tall
Small firm testes
Infertile
Gynaecomastia
Low testosterone
LH and FSH raised
Glucagon dosing for hypo’s in children
Under 1 yo
>1yo and <25kg
>1yo >25kg
Under 1 yr old - 500mcg
Over 1 yr old AND <25kg - 500mcg
Over 1 yr old AND >25kg - 1mg
