Chem Path 2 Flashcards by Elliot Colman

Roles of T4

Regulating basal metabolic rate

Potentiating responses to catecholamines

How well did you know this?

Not at all

Perfectly

Hypothyroidism causes

AI (most common in UK) -> Primary atrophic with no goitre, Hashimoto’s (goitre and anti-TPO/TG)

Iodine Deficiency (most common worldwide) 
Surgery/radioactive ablation

Drugs

How well did you know this?

Not at all

Perfectly

Which drugs can cause hypothyroidism

Lithium, Amiodarone, Carbimazole

How well did you know this?

Not at all

Perfectly

How does amiodarone affect the thyroid gland?

Hyper -> Contains iodine, used as substrate to synthesise thyroxine

Hypo -> Amiodarone is toxic to thyroid tissues

How well did you know this?

Not at all

Perfectly

Hypothyroidism Management

Levothyroxine orally
Titrate to normal TSH, 6 weekly TSH tests
Higher dose in pregnancy

How well did you know this?

Not at all

Perfectly

How to treat myxoedema coma

IV Liothyronine

How well did you know this?

Not at all

Perfectly

Sick euthyroid

In severe illness, body shuts down metabolism to conserve energy

Low T3/4

High TSH then low TSH

How well did you know this?

Not at all

Perfectly

Subclinical Hypothyroidism

Pre-hypothyroid with pituitary compensation

High TSH, normal T3/4

High chance of hypothyroidism if Anti-TPO positive

How well did you know this?

Not at all

Perfectly

Causes of Hyperthyroidism

AI - Graves'
De Quervain's 
Thyroid Adenoma
Amiodarone
Toxic Multinodular Goitre
Postpartum

How well did you know this?

Not at all

Perfectly

Graves’ Specific symptoms

Pretibial Myxoedema

Grave’s Orbitopathy (Proptosis)

How well did you know this?

Not at all

Perfectly

Investigations in Hyperthyroidism

ECG
TFTs, U&Es, Anti-TSHr
USS
Thyroid Uptake scan

How well did you know this?

Not at all

Perfectly

Hyperthyroidism management

Smoking cessatioon

Carbimazole/Propylthiouracil (Titrate or block and replace)
Beta Blockers
Lugol’s Iodine
Radio-iodine

Thyroidectomy, must be euthyroid before surgery

How well did you know this?

Not at all

Perfectly

Pituitary Mass

Adenoma
Macroadenoma = >1cm, non-functional but can be prolactinoma

Microadenoma =<1cm, secrete GH/Prolactin, cause acromegaly

How well did you know this?

Not at all

Perfectly

Pituitary Mass Symptoms

Bitemporal Hemianopia

Hyperprolactinaemia = gynaecomastia, galactorrhoea, amenorrhoea, loss of libido, impotence

Somatotrophin = Acromegaly (Tissue growth, heart failure, hypertension, DM)

How well did you know this?

Not at all

Perfectly

Investigating Pituitary Mass

Imaging

Acromegaly -> IGF-1 > OGTT

Prolactin >6000 = prolactinoma

How well did you know this?

Not at all

Perfectly

Pituitary Mass management

Octeotride (somatostatin analogue)

Cabergoline/Bromocriptine (Dopamine agonist)

Pegvisomat (GH Receptor Antagonist)

Radiotherapy

Trans-sphenoidal debulking

Monitor with GH/Prolactin

How well did you know this?

Not at all

Perfectly

Thyroid Tumours

Papillary >

Follicular (Good prognosis) >

5% Medullary (MEN2, C-Cells and calcitonin) >

Lymphoma (risk in Hashimoto’s) >

Anaplastic -> Elderly, undifferentiated, poor prognosis

How well did you know this?

Not at all

Perfectly

Treatment of Papillary/Follicular Thyroid Tumour

Sugery +/i radioactive iodine

Replace thyroxine to suppress TSH

Monitor Thyroglobulin levels

How well did you know this?

Not at all

Perfectly

Which pituitary cells do hypothalamic hormones stimulate

DA -/> Lactotroph -> Prolactin

TRH -> Thyrotroph -> TSH

VP/CRH -> Corticotroph -> ACTH

GnRH -> Gonadotrophs -> LH/FSH

GHRH -> Somatotrophs -> GH

SS -/> Somatotrophs

How well did you know this?

Not at all

Perfectly

Hypopituitarism causes

Malignancy (Adenoma>Craniopharyngioma)

Infection -> TB, syphilis

Infiltrative -> Sarcoid, Lymphoma

Iatrogenic -> Surgical, Trauma, radiation

Infarct -> Sheehan’s, Apoplexy

How well did you know this?

Not at all

Perfectly

Hypopituitarism Presentation

Generic = Wt gain, tiredness, low bp etc

Sex Hormones = impotence, no periods/libido

ACTH = Addisonian Crisis

TSH = Myxoedema Coma

How well did you know this?

Not at all

Perfectly

Hypopituitarism Investigation

Combined Pituitary Function Test

Give GnRH, TRH, Insulin

Measure pituitary hormones every 30 mins

CT/MRI

How well did you know this?

Not at all

Perfectly

Hypopituitarism Management

Replacement cheaper/easier than control

Adrenal Histology

Outside to Inside

Capsule 
Glomerulosa (Aldosterone) 
Fasciculata (Cortisol)
Reticularis (Sex Hormones)
Medulla (Catecholamines)

Addison's

Low Aldosterone and Cortisol

Addison's Causes

Primary = Iatrogenic, AI, TB, Infarct, Malignancy Secondary = Pituitary

Addison's Presentation

``` Postural Symptoms Wt Loss Fatigue Vomiting, Salt Craving Skin/Mucosal Pigmentation ```

Addison's Investigations

9am Cortisol >350 excludes Electrolytes (Low sodium, High Potassium) Serum ACTH Glucose SynACTHen rises in secondary disease

Addison's Management

Replace w/ Hydro/Fludrocortisone + Sick day rules

Cushing's causes

Primary = adrenal malignancy Secondary = Pituitary adenoma, ectopic production, ACTH (SSLC) Iatrogenic

Cushing's investigations

Dexamethasone Suppression test Low dose confirms Cushings High dose determines cushings syndrome or disease

Cushing's Management

Primary -> Adrenalectomy +/- steroid replacement Ectopic -> Ketoconazole, Metyrapone, Mifepristone

Nelson's Syndrome

Adrenal removal leads to raised ACTH, causing ACTH producing pituitary tumour to grow Bitemporal Hemianopia Tanned

Conn's causes

Adrenal Hyperplasia | Adrenal Adenoma/Carcinoma

Conn's Presentation

Treatment resistant HTN Low Potassium High Sodium

Conn's Investigations

Electrolytes, Aldosterone:renin ratio is raised Adrenal vein sampling Imaging

Conn's Management

``` Aldosterone antagonist (Spironolactone) Surgery ```

Phaeochromocytoma

Pulses of HTN, arrhythmias, sweating Used to be vanillymandelic acid, now 24h catecholamines (TCAs, CCBs, Beta Blockers can cause false positive) Caused by adrenal medulla tumour (adrenline) or peripheral nerual tumour (noradrenaline)

Phaeochromocytoma associations

MEN 2 A/B NF-1 VHL

MEN 1

Pituitry Adenoma Parathyroid Hyperplasia Pancreatic Tumour

MEN 2A

Phaeochromocytoma Pituitary Hyperplasia Medullary Thyroid

Men 2B

Mucosal Neuroma Marfinoid Medullary Thyroid Phaeochromocytoma

T1DM antibodies

ICA IAA GADA IA-2A

Pre-Diabetes results

Fasting - 6.1-6.9 OGTT - 7.8-11 HbA1c - 42-47 Random - 7.8-11

Diabetes results

Fasting - >7 OGTT - >11.1 HbA1c - >48 Random - >11.1

T2DM management

Metformin Add: Sulphonylurea, DPP-4 Agonist, SGLT-2 Inhibitor Add GLP-1 Agonist or two of above

HHS

Insulin resistance causes persistent hyperglycaemia Causes osmotic diuresis Confusion, dehydration Raised glucose, osmolarity, usually no ketones/acidosis

HHS treatment

IV fluids 3-6l/24h .9%. NaCl +/- KCl Not too quick as can cause central pontine myelinolysis Monitor with BMs (fall of 5mM/h) and ketones - add insulin if ketones rising

DKA

Absolute insulin deficiency Body starving = unregulated ketosis = acidosis Causes - common = missed insulin doses

DKA investigations

ketones >3 pH <7.3 BM>15 ``` Find cause (FBC, cultrues, CXR, Urinalysis) Find damage (U&Es, ABG, ECG) ```

DKA Management

Fluids Rapid then taper KCl if <5.5 IV Insulin .1u/kg + normal dose 10% Dextrose when BM<15 Catheter, urine = at least .5ml/kg/hr Hourly ketones/BM

Acute Porphyrias with skin symptoms

Variegate Porphyria (Protoporphyrinogen oxidase def.) Hereditary Coproporphyria ( Copropophyrinogen oxidase def.)

Acute Porphyrias

Acute Intermittent Porphyria (PBG deaminase/HMB Synthase inhibitor) ALA-dehydratase deficiency porphyria (ADP)

Cutaneous Porphyrias

Porphyria cutanea tarda (PCT) Erythropoietic protoporphyria (EPP) X-Linked erythropoietic protoporphyria (XLEPP) Congenital erythropoietic porphyria (CEP)

Porphyria?

Enzyme deficiency in Glycine/Succinyl-CoA to Haem synthesis pathway leads to buildup of intermediate