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Flashcards in Endocrinology Deck (27)
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1

What antibody to Grave's and Hashimoto's have in common?

Anti-TSH Receptor antibodies

- Grave's: activate receptor

- Hashimoto's: inhibit receptor

2

Pt presents with sweating and wt loss despite increased appetite. On examination, you note diffuse goitre + bruit, pretibial myxoedema (shin rash) and their eyes gritty. They smoke.

Likely diagnosis? Investigations?

Management?

Grave's disease

Investigations:
TFT - low TSH, high T3

Serology - TRAb, Anti-TPO

Management:
1. Propanolol - immediate relief

2. Carbimazole
- titrate down if healthy
- titrate up if elderly

OR Block & Replace with Carbimazole + Thyroxine

3. 131_I
4. Thyroidectomy

+ Stop smoking! (big RF for Grave's eye disease)

3

Pt presents with constipation, wt gain and numbness in their hands. Their hair appears brittle and their skin dry/. Examination reveals cardiomegaly and bradycardia, as well as a large tongue. They also have a positive Hertoghe sign.

Likely diagnosis, investigations, management + risks

Hypothyroidism

TFT - high TSH, low T3

Serology - Hashimoto's?

Management:
LEVOTHYROXINE
(Risks = osteoporosis, arrhythmia)

+ annual TSH check

4

Pt presents with constipation, wt gain and numbness in their hands. Their hair appears brittle and their skin dry/. Examination reveals Goitre, hypertrophy and hyperplasia.

Likely diagnosis, risk factors, investigations, management + risks

Hashimoto's thyroiditis

RF: Turner's/ Down's syndrome; HLA-DR5; T1DM, SLE, etc

Inv: TFT - high TSH, low T3
GOLD: High Anti-TPO (Anti-thyroid Peroxidase Ab).
Low Thyroglobulin Ab. Anti-TSH_R Ab

5

Pt arrives from the Middle East complaining of fatigue, constipation and neck swelling.

Exam reveals large, diffuse, non-tender goitre.

TFT shows hypothyroidism. Serology is negative. Likely cause?

IODINE DEFICIENCY

- most common world-wide cause
- Middle-East, Nepal, South-America

6

What drugs interfere with levothyroxine absorption?

IRON - Ferrous Sulphate
- take Levothyroxine THEN iron 2-4 hrs apart

Calcium chloride
Digoxin
Hormone Replacement Therapy

7

Half life of levothyroxine

4-6 weeks

8

Pt presents with heat intolerance, sweating and palpitations. She is 11 weeks pregnant. TFT reveals raised T3 and low TSH.

Management?

PROPYLTHIOURACIL (PTU)

Carbimazole is contraindicated in 1st trimester of pregnancy (crosses placenta > aplasia cutis)

9

Painful goitre

De Quervain's thyroiditis

10

Secondary causes of Hyperthyroidism

Amiodarone
Lithium
TSH-adenoma
Choriocarcinoma (B-hCG activates TSH receptor)/ gestational
Struma ovarii

11

Thyroid storm management

IV Propanolol
IV digoxin

Propylthiouracil via NG tube THEN Lugol's Iodine 6hrs later

Prednisolone/ HC

12

Grave's disease cardinal features

Diffuse goitre + bruit
Pretibial myxoedema (shin rash)
Infiltrative eye disease
- exophthalmos
- periorbital oedema
- opthalmoplegia

13

Pt diagnosed with thyrotoxicosis and is started on Carbimazole + Propanolol. She initially felt better but now complains of a sore throat.

Management?

STOP CARBIMAZOLE + FBC

SE: Agranulocytosis > Neutropenia > sepsis

*also a side-effect of PTU

14

Pt is 7 weeks into pregnancy and has a Hx of hypothyroidism. It is well managed with levothyoxine.

TFT shows:
- fT4 = 18 (11-22)
- TSH = 2.1 (0.17-3.2)

Management?

Increase Levothyroxine by 25 mcg + Repeat TFT in 4 weeks

EVEN IF IN EUTHYROID STATE

- in preg, there is ^fT4 until week 12 :: foetus is dependant on maternal T4 until their foetal T4 develops at wk12.

15

Pharmacology + SE of Carbimazole

Inhibits Thyroid Peroxidase in Follicular cells > inhibits iodination of tyrosine residues in thyroglobulin > stops T3/4 production.

SE: Rash, pruritus, agranulocytosis (> neutropenia > sepsis)

16

Acromegaly investigations + management

Investigations
1L: IGF-1?

GOLD: Oral Glucose Tolerance Test - GH not suppressed

MRI - prolactinoma?

Management
1L TRANS-SPHENOIDAL SURGERY

2L
a) Somatostatin receptor ligands - OCTREOTIDE
b) GH Antagonist - PEGVISOMANT
c) Dopamine agonist - CABERGOLINE
d) Radiotherapy

Repeat IGF-1 + random GH 3 months after

17

Acromegaly is a RF for which GI disturbance?

Colonic polyps - can become malignant

Require colonoscopy every 5 years

18

Hypothalamic-pituitary-adrenal axis

Hypothalamus >> CRH > Pituitary >> ACTH > Adrenals >> Adrenocorticoids (cortisol, aldosterone, testosterone)

CRH = Corticotropin-releasing hormone

ACTH = Adrenocorticotropic Hormone

19

Hypothalamic-pituitary-ovary axis

Hypothalamus >> GnRH > Anterior Pituitary >> LH, FSH > ovaries

LH - stimulates oestrogen
FSH - stimulates inhibin

20

Growth hormone axis

Hypothalamus >> Somatostatin (-) or GHRH (+) on GH.

Stomach >> Ghrelin (+) on GH


GHRH/ Ghrelin(+) > Ant Pit >> GH > Liver >> IGF-1 > cells, muscles, bones

21

Raised PTH
Hypocalcaemia
Hypophosphatemia

Secondary Hyperparathyroidism

Causes: CKD, vit D deficiency

Mx: Give calcium

22

Raised PTH
Hypercalcaemia
Hypophosphatemia

Primary Hyperparathyroidism
(Parathyroid adenoma)

Mx: Remove adenoma

23

Raised PTH
Hypercalcemia
Hyperphosphatemia

Tertiary hyperparathyroidism
(autonomous hyperplasia)

Mx: Parathyroidectomy

24

Hypertension
Hyperkalaemia
Metabolic acidosis

Conn's Syndrome (adrenal adenoma) - Primary hyperaldosteronism

25

Addison's disease presentations

Investigations, management

Tanned, tired, tearful, thin, throwing up + hypotension

= adrenal insufficiency
- low cortisol
- low aldosterone

Mx: Hydrocortisone + Fludrocortisone (replacement)

26

Long-term steroid use complications

- Diabetes Mellitus
- Immunosuppression
- Osteoporosis
- Proximal weakness
- Thin skin

27

Pt presents with a 2 day history of vomiting and fatigue. She is disorientated and looks clinically dry.

Her BP is 92/50. Pulse 105. RR 20. Sats 98%. Temp 36.4.

ABG: PaO2 13kPa, pH 7.3, PaCO2 4.1 kPa, HCO3 13mmol/L.

Capillary blood glucose is 32mmol/L and urine dispstick shows Glucose +++, ketones +++

Likely diagnosis? Pathophysiology?

Diabetic Ketoacidosis

No insulin = hyperglycaemia...

- Osmotic diuresis > polyuria, dehydration, polydipsia (to get rid of glucose)

- Glucose not utilised :. lipolysis upregulated for energy source > ketoacidosis > metabolic acidosis

- respiratory compensation for MA > hyperventilation to blow off CO2

= Kussmaul respiration