Endo Flashcards
What is Acromegaly?
A disorder of excessive growth hormone
what is the most common cause of acromegaly?
Pituitary adenoma - 95%
what is gigantism?
excessive GH secretion before epiphyseal closure, during childhood or adolescence leading to increased linear growth
what are 5 rarer causes of acromegaly?
Bronchial carcinoid tumour
Lung carcinoids
Pancreatic islet cell tumour
Phaeochromocytoma
Paraneoplastic syndrome due to ectopic growth hormone releasing hormone (GHRH) or growth hormone (GH) secretion
what 2 hormones inhibit the secretion of GH?
Dopamine
Somatostatin
what is the pathophysiology of acromegaly?
Increased GH => increased glucose release, muscles retain nitrogen causing them to grow => epiphyseal plates fused so can only grow in places where there is still growth => jaw, nose, hands, feet
5 symptoms of acromegaly?
Bigger hands, feet and face
excessive sweating
tiredness
weight gain
headache
deep voice/amenorrhoea
6 signs of acromegaly?
Bi-temporal hemianopia
spade like hands and feet
large tongue - macroglossia
Jaw protrusion - prognathism
interdental seperation
predominant forehead
what are 6 conditions related to acromegaly?
Hypertrophic heart
Hypertension
T2DM
Carpal tunnel syndrome
Colorectal cancer
what is the 1st line investigations for acromegaly?
Raised insulin like growth factor 1
What is the gold standard test for acromegaly to comfirm diagnosis after 1st line testing?
oral glucose tolerance test
- in normal patients GH suppressed to <2 with hyperglycaemia
- no suppression of GH in acromegaly
what scan can be used in acromegaly?
MRI pituitary - ?pituitary tumour
What is the 1st, 2nd and 3rd line management for acromegaly?
1st line - trans-sphenoidal surgery if pituitary adenoma
2nd line -
- Cabergoline (dopamine agonist)
- Somatostatin analogue (octreotide)
- Pegvisomant - GH receptor antagonist give SC OD
3rd line - Radiotherapy,
What are 5 complications of acromegaly?
T2DM
Arthritis and carpal tunnel
Cardiac - cardiomyopathy, heart failure, HTN
Colorectal cancer
Obstructive sleep apneoa
what visual field defect is associated with acromegaly?
Bitemporal hemianopia
what is the inheritance pattern for inherited multiple endocrine neoplasia?
autosomal dominant
what are the 3 different types of multiple endocrine neoplasia?
MEN1
MEN2A
MEN2B
what is the most common presentation of MEN1?
hypercalcaemia
what is the most common cancer associated with multiple endocrine neoplasia 1?
Pituitary adenoma - 60% of MEN1 patients
what is the cause of MEN1?
mutations in MEN1 tumour supressor gene
what is the presentation of multiple endocrine neoplasia (MEN) 1?
3Ps
Primary Hyperparathyroidism
Pancreatic neuroendocrine tumour (50%)
Pituitary Adenoma (70%)
Also adrenal and thyroid cancers
what is Addison’s disease?
Autoimmune destruction of the adrenal glands leading to reduced cortisol and aldosterone production
Most common cause of primary hypoadrenalism in UK
what are 5 causes of secondary adrenal insufficiency?
Underacting pituitary not releasing ACTH
congenital underdevelopment (hypoplasia) of pituitary
Pituitary surgery
infection
loss of blood flow to pituitary - apoplexy
Pituitary radiotherapy
what is the cause of tertiary adrenal insuficiency?
Inadequate CRH release from hypothalamus
Usually due to long term steroid use (>3 weeks) which suppresses hypothalamus
What are 3 risk factors for Addison’s?
Female
Autoimmune diseases
HIV/TB
What are 8 clinical presentations of Addison’s?
Hypotension
Metabolic acidosis
Hypoglycaemia
Hyponatraemia and Hyperkalaemia
Lethargy, weakness, anorexia
Nausea and vom
Weight loss
Salt craving
Hyperpigmentation - especially of palmar creases
is hyperpigmentation a feature of secondary or tertiary adrenal insuficiency?
NO - only primary (addisons)
why does Addison’s cause skin hyperpigmentation?
High ACTH leads to stimulation of melanocytes
what is the gold standard test for Addison’s?
ACTH stimulation test (synacthen’s test) - low
what is an alternative investigation for Addison’s disease if the gold standard is unavailable?
9am serum cortisol
> 500 - Addison’s unlikely
<100 - abnormal
100-500 - send for ACTH stimulation test
What is the management for Addison’s?
Daily -Hydrocortisone - 20-30gm per day
AND
Fludrocortisone
Emergency -
medical alert bracelets/cards
Hydrocortisone for injection
what are the sick day rules in addison’s disease?
Double glucocorticoids (hydrocortisone)
Fludrocortisone remains the same
what is the management of an Addisonian crisis?
Hydrocortisone 100mg IV/IM
1L NaCl over 30-60 mins + dextrose if hypoglycaemic
Hydrocortisone 6 hourly until stable
oral replacement after 24 hours
what are 3 complications of Addison’s?
Secondary Cushing’s syndrome (too much glucocorticoid replacement)
osteopenia/porosis
treatment related hypertension
What is Cushing’s syndrome?
features of prolonged high levels of glucocorticoids in the body
what are the 2 corticosteroid hormones?
glucocorticoids - cortisol
mineralocorticoids - aldosterone
what is Cushing’s disease?
pituitary adenoma secreting excessive adrenocorticotrophic hormone (ACTH) stimulating excessive cortisol release from adrenal
what are 6 actions of cortisol (glucocorticoids)?
Increased alertness
inhibits immune system and reduces inflammation
inhibits bone formation
Raises blood glucose
increases metabolism
Supports cardiovascular function
when in the day is cortisol the highest?
morning
what are 3 medication that act as glucocorticoids (cortisol)?
Prednisolone
Hydrocortisone
Dexamethasone
what is the action of mineralocorticoids (aldosterone)?
Increase sodium reabsorption from distal tubule
Increase potassium secretion from distal tubule
Increase hydrogen secretion from collection ducts
what medication mineralocorticoid?
fludrocortisone
Is Cushing’s more common in women or men?
women
what are 4 causes of Cushing’s syndrome?
CAPE
Cushing’s disease - pituitary adenoma releasing excessive ACTH - MOST COMMON
Adrenal adenoma - adrenal tumour secreting cortisol
Paraneoplastic syndrome
Exogenous steroids
what are 4 causes of pseudo cushings?
Alcohol excess
severe depression
obesity
pregnancy
what tumour commonly causes paraneoplastic cushing’s syndrome?
small cell lung cancer
What are 4 risk factors for Cushing’s?
Exogenous corticosteroid use
pituitary/adrenal adenoma
adrenal carcinoma
small cell lung cancer
What are 8 clinical manifestations of Cushing’s?
Moon face
Central obesity
Abdominal striae
Enlarged fat pad on back - buffalo hump
Proximal limb muscle wasting - difficulty standing from sitting
Hirsutism
Easy bruising and skin healing
Hyperpigmentation of skin
what are 6 complications of cushing’s syndrome?
Hypertension
cardiac hypertrophy
T2DM
Dyslipidaemia
Osteoporosis
Adverse mental health
what can be seen on blood gas in cushings?
hypokalaemic metabolic alkalosis
what investigation is used to diagnose cushing’s syndrome?
dexamethasone suppression test
what are the 3 different types of dexamethasone suppression test?
low dose overnight test - 1mg
low dose 48 hour test - 0.5mg every 6-8 hours
High dose 48 hour test - 2mg every 6-8 hours
what investigation can be used to differentiate between cushings and pseudo-cushings?
insulin stress testing
What is the management of Cushing’s?
1st line - treat cause - trans-sphenoidal pituitary adenectomy/ adrenalectomy/removal of small cell lung cancer
adjuncts - post surgery corticosteroid/non-corticosteroid replacement, chemo, radiotherapy on primary tumour
what is nelson’s syndrome?
development of ACTH producing pituitary tumour after the surgical removal of both adrenal glands due to lack of cortisol and negative feedback - causes skin hyperpigmentation, bitemporal hemianopia and lack of other pituitary hormones
is reoccurrence common with Cushing’s?
Yes
What is T1DM?
a metabolic autoimmune disorder characterised by hyperglycaemia due to destruction of insulin producing beta cells in the islet of langerhans in the pancreas, results in absolute insulin deficiency.
what are 3 risk factors for T1DM?
Genetics
Other autoimmune disease
Viral tiggers - coxsackie, enterovirus
what causes T1DM?
autoimmune pancreatic beta cell destruction
subclinical until 80-90% of beta cells have been destroyed
what is the blood glucose target fasting and at other times of day?
5-7 mmol/L - Fasting
4-7 mmol/L usually
5-9 mmol/L - after meals
How does insulin reduce blood glucose?
Causes cells to take up glucose
causes muscle and liver cells to store glucose as glycogen
where is glucagon produced?
Alpha cells of islets of Langerhans
How does glucagon increase blood glucose?
Breaks down glycogen in liver into glucose - glycogenolysis
Causes liver to convert fats and protein to glucose - gluconeogenesis
What are 8 clinical manifestations of T1DM?
polyuria + polydipsia + hunger
blurred vision
fatigue/tiredness
weight loss
recurrent infections
secondary enuresis
KETOACIDOSIS
what is an atypical presentation of T1DM and what additional test can be done?
> 50 year
BMI > 25
C-peptide
what 5 tests should a new type 1 diabetic get?
FBC, U+E
HbA1c
TFTs and anti-TPO
anti-TTG
Insulin antibodies, anti-GAB, islet cell antibodies
What is the management of T1DM?
1 - Basal-bolus insulin given once daily
Short acting insulin given 30 mins before carbohydrate intake
2 - fixed insulin dosing in those who cannon self-manage
What are 3 side effects of insulin?
hypoglycaemia
weight gain
lipodystrophy
what are 3 different types of long acting insulin and their brand names?
Insulin detemir - Levemir
Insulin glargine - Lantus - Abasaglar, Semglee, Toujeo
Insulin degludec - Tresiba
what is the onset on long acting insulins?
duration of action of up to 24 hours - produce steady state in 2-4 days
what are 3 examples of intermediate acting insulins?
Humalin I
Insuman basal
Insulatard
how long is the onset and action of intermediate insulins?
onset 1-2 hours with maximal effects at 3-12 hours
11-24 hour duration
what are 2 examples of short acting insulin?
Actrapid
Humulin S
what is the onset and duration of short acting insulin?
onset in 30-60 mins
up to 8 hour duration
what are 2 examples of rapid acting insulins?
Humalog - insulin lispro
Novorapid - insulin aspart
what is the onset and duration of rapid acting insulin?
Onset 15 mins
duration 2-5 hours
what is the 1st line long acting insulin choice?
Insulin detemir - levemir
when is metformin added in T1DM?
BMI >25
what is needed for a child to qualify for an insulin pump on the NHS?
> 12 years
Difficulty controlling HbA1c
what are 2 different types of insulin pumps?
tethered - replaceable infusion sets and insulin that attaches with belt around patient waist - has wires
patch - sits directly on skin without any tubing, replace entire patch when runs out
what are the sick day rules for T1DM?
Do not stop insulin
check BMs more often - every 1-2 hours
Check urine ketones
Maintain normal meal pattern if possible - replace with sugary drinks if reduced appetite
Aim to drink 3L of water
How often should T1 diabetics have their HbA1c measured?
every 3-6 months
How often should people with T1DM measure blood glucose?
4x per day Adults
5x per day children
MINIMUM
What are the 3 microvascular complications of Diabetes?
retinopathy
peripheral neuropathy
nephropathy
what are 4 macrovascular complications of diabetes?
coronary artery disease
cerebrovascular disease
peripheral artery disease
Hypertension
what are 4 infection related complications of diabetes?
UTI
Pneumonia
Skin and soft tissue infections
Fugal infections - candida
what are the legal requirements of a person on insulin or sulfonylureas?
inform DVLA of insulin use
No severe hypoglycaemia in past 12 months
Full hypoglycaemic awareness
Adequate control of condition with BM monitoring at least BD and before driving
Understand risks of hypoglycaemia
No other complication
what are 8 patients where HbA1c should not be used to diagnose DM?
<18 years
Pregnant or <2 mon PP
Symptoms <2 months
Acutely unwell
On medications that can cause hyperglycaemia
Acute pancreatic damage/surgery
End stage CKD
HIV
what are 4 people to use HbA1c with caution in?
Abnormal haemoglobin - haemoglobinopathies
anaemia
altered red cell lifespan
recent blood transfusion
what is T2DM?
A metabolic disorder of hyperglycaemia due to a combination of insulin resistance and deficiency leading to persistently high blood glucose
what are 6 risk factors for T2DM?
Non-modifiable
older age ethnicity
FHx
Modifiable
Obesity
Sedentary lifestyle
High carbohydrate diet
what is the pathophysiology of T2DM?
Repeated exposure to glucose and insulin causes cell resistance to insulin leading to more insulin needing to be produced. This fatigues the pancreas causing insulin output to be reduced
High carb diet plus insulin resistance and reduced pancreatin functioning leads to chronic hyperglycaemia and it’s micro and macovascular complications
what is the pathophysiology of T2DM?
post receptor resistance
50% of beta cell mass usually lost => greater amounts of insulin produced by fewer beta cells => hyperglycaemia and lipid excess are toxic to beta cells.
What are 7 clinical manifestations of T2DM?
polyuria, nocturia + polydypsia
Weight loss and fatigue
glycosuria
Acanthosis nigricans - black pigment on nape of neck and axillae
Opportunistic infections
slow wound healing
what is the HbA1c in pre-diabetes?
42-47 mmol/mol
what is the HbA1c target for a new diabetic?
48 mmol/mol
what is the HbA1c target for a patient requiring more than one antidiabetic?
53 mmol/mol
How often is HbA1c measured in T2DM?
3-6 monthly until stable
What is the 1st line management of T2DM?
LIFESTYLE
what is the 1st line medication in T2DM?
Metformin 500mg OD initially
Can increase up to 2g OD/1g BD
what is the 1st line medical management of T2DM if metformin is contraindicated?
with CVD - SGLT-2 inhibitor
NO CVD - DDP-4 inhibitor or pioglitazone or sulfonylurea
what additional medication should people with Diabetes AND CVD, heart failure or a Qrisk >10% be put on?
SGLT-2 inhibitor
what is the 2nd line management of T2DM?
ADD
Sulfonylurea
OR
Pioglitazone
OR
DPP-4 inhibitor
OR
SGLT-2 inhibitor
what is the 3rd line management of T2DM?
Tripple therapy - metformin + 2 others
OR
Insulin therapy
what is one option in T2DM if triple therapy fails in a patient with BMI >35?
switch one drug to GLP-1 mimetic (liraglutide)
what class is metformin?
Biguanide
what does metformin do?
increases insulin sensitivity and decreases glucose production by liver
does not cause weight gain or hypoglycaemia
what are 2 notable side effects of metformin?
GI symptoms - trial of MR formulation
Lactic acidosis - usually secondary to AKI - stop in AKI
what are 4 examples of SGLT-2 inhibitors?
empagliflozin
canagliflozin
Dapagliflozin
Ertugliflozin
what is the MOA of SGLT-2 inhibitors?
Block resorption of glucose in kidneys by sodium glucose co-transporter 2 proteins in proximal tubule
leads to reduced BMs, BP, weight loss, improves heart failure
what are 7 notable side effects of SGLT-2 inhibitors?
Normoglycaemic DKA
Glycosuria
Increased frquency and urgency
Weight loss
Genital and UTIs
lower limb amputaton
Fournier’s gangrene
what is the MOA of pioglitazone?
Thiazolidinedione that increases insulin sensitivity and decreases liver production of glucose
DOES NOT typically cause hypoglycaemia
what are 4 notable side effects of pioglitazone?
weight gain
heart failure
increased fracture risk
small increased risk of bladder cancer
how do sulfonylureas work?
stimulate insulin release from pancreas
what is the most common sulfonylurea?
gliclazide
what are 4 notable side effects of sulfonylureas?
weight gain
hypoglycaemia
SIADH
Liver dysfunction
what are 2 examples of DDP-4 inhibtors?
Sitagliptin
Alogliptin
how do DPP-4 inhibitors work?
block action of DDP-4 which allows for increased incretin (GLP-1) activity by decreasing peripheral breakdown and allowing for increased insulin secretion, inhibition of glucagon production, slower absorption from GI tract
what are 2 notable side effects of DPP-4 inhibitors?
Headaches
Acute pancreatitis
what are 2 examples of GLP-1 mimetics?
exenatide
liraglutide
what are 3 side effects of GLP-1 mimetics?
weight loss
reduced appetite
GI symptoms
what is seen as impaired fasting glucose?
fasting glucose 6.1-7.0
then >7 = diabetes
what is the inheritance of MODY (maturity onset diabetes of the young)?
Autosomal dominant
usually onset <25 years
what are the features of MODY?
Usually picked up incidentally
presents with non-ketosis hyperglycaemia and patients are often a normal weight
usually does not require treatment or can be treated with sulfonylureas or insulin
What is Grave’s disease?
An autoimmune thyroid condition associated with hyperthyroidism and over production of thyroid hormones
are thyroid disorders and cancers more common in men or women?
women
what causes Grave’s disease?
thyroid hormone overproduction stimulated by TSH receptor antibodies
can be genetic
What are 4 risk factors for Grave’s disease?
FHx
Autoimmune disease
Stress
High Iodine intake
What is the pathophysiology for Grave’s disease?
TSH receptor autoantibodies cause thyroid hormone hyperproduction as well as thyroid hypertrophy and hyperplasia of thyroid follicular cells resulting in the clinical manifestations of hyperthyroidism and diffuse goiter.
What are 6 clinical presentations of Grave’s disease?
Thyroid acropachy - clubbing, and hand swelling
Thyroid bruit
Pretibial myxoedema
Diffuse goitre
Thyroid eye disease
Hyperthyroidism signs - heat intolerance, sweating, tremor
What is the diagnostic test for Grave’s disease?
serum TSH receptor antibodies - present
what are 4 differential diagnoses for Grave’s disease?
toxic nodular goitre
post-natal thyroiditis
TSH producing pituitary adenoma
Excessive thyroxine
What is the management of Grave’s disease?
1 - Carbimazole 15-40mg OD for 4-8 weeks then reduce gradually over 12-18 months
2 - Propylthiouracil 200-400mg OD till euthyroid then reduce over time
3 - radioactive iodine treatment, thyroidectomy
Beta blockers - propranolol 10-40mg T/QDS - for symptom control
what are 2 adverse effects of carbimazole?
Acute pancreatitis
Agranulocytosis (also propylthiouracil)
what are 6 complications of graves disease?
AF
Pregnancy related issues - miscarriage, prem, thyroid dysfunction of foetus
Sight threatening orbitopathy
Osteoporosis
Congestive heart failure
Thyroid storm
what is thyroid storm?
rare but life threatening sudden significant rise in thyroid hormone levels resulting in fever, profuse sweating, diarrhoea, vomiting, delerium, profound weakness, seizure, jaundice, raised HR, BP and temp and eventually coma
what are 4 complications of Grave’s disease?
bone mineral loss
AF/congestive heart failure
sight threatening complications
elephantiasis dermopathy
what is Hashimoto’s thyroiditis?
an autoimmune-mediated lymphocytic inflammation of the thyroid gland resulting in a destructive thyroiditis with release of thyroid hormone causing transient hyperthyroidism (for 2/3 months) then permanent hypothyroidism
what are 3 risk factors for Hashimoto’s thyroiditis?
Female
Autoimmune disease
genetics - Turner’s/Down’s
what antibodies cause Hashimoto’s thyroiditis and what do they do?
ant-Thyroid peroxidase antibodies
attack thyroid cells causing fibrosis and the release of stored thyroid hormone causing transient hyperthyroidism for a few months before stores run out and permanent hypothyroidism ensues
what are 3 features of hashimoto’s thyroiditis?
Hypothyroidism features
firm non-tender goitre
anti-TPO antibodies
what is the gold standard test for Hashimoto’s thyroiditis?
serum ant-Thyroid peroxidase antibodies
what is the management of Hashimoto’s?
levothyroxine
what are 3 complications of Hashimoto’s?
Atrial fibrillation
IHD/CHF
low risk of developing Grave’s disease
what is the prognosis for Hashimoto’s thyroiditis?
Permanent hypothyroidism and treatment with levothyroxine
What is defined as the normal range for serum potassium?
3.5-5.3 mmol/L
what is seen as mild hyperkalaemia?
5.4-5.9 mmol/L
what is seen as moderate hyperkalaemia?
6-6.4 mmol/L
what is seen as severe hyperkalaemia?
> 6.5 mmol/L
what are 7 causes of hyperkalaemia?
AKI
CKD - stage 4/5
Rhabdomyolysis
Adrenal insufficiency - Addison’s disease
Tumour lysis syndrome
Massive blood transfusion
Medications
what are 6 medications that can cause hyperkalaemia?
Aldosterone antagonists - spironolactone, eplerenone
ACEi
ARBs
NSAIDs
Ciclosporin - calcineurin inhibitors
heparin
what are 4 clinical manifestations of hyperkalaemia?
Muscle cramps/ weakness
ECG changes
Paraesthesia
Palpitations
what 5 ECG changes are present in hyperkalaemia?
Tall peaked (tented) T waves
Long PR (>200ms)
Loss of P waves
Broad QRS (>100ms)
Sinusoidal wave pattern
Can cause ventricular fibrilation
what are the 2 indications for emergency treatment of hyperkalaemia?
ECG changes
Potassium >6.5 mmol/L
what is given in a hyperkalaemic emergency?
IV calcium gluconate/chloride 10ml 10% - stabilise cardiac membrane (does not lower K+)
Insulin/glucose infusion - 10 units insulin and 25g glucose - given over 15-30 mins
Nebulised salbutamol
Haemodialysis
what is a complication of hyperkalaemia?
life threatening arrhythmias and cardiac arrest
what can be given in hyperkalaemia to bind potassium?
Sodium ziconium cyclosilicate 30mg PR
Patiromer calcium
No longer recommended -Calcium polystyrene sulfonate (resonium) - enema or oral - enema more effective
What is the pathophysiology of Hyperosmolar Hyperglycaemic state?
Hyperglycaemia drives osmotic diuresis leading to fluid and electrolyte loss
Due to small amounts of insulin present lipolysis does not occur hence no ketoacidosis
what are 5 key features of HHS?
Hyperglycaemia
Hyperosmolality (>320 mosmol/Kg)
Dehydration
Electrolyte abnormalities
WITHOUT Ketoacidosis
what are 3 risk factors for HHS?
Infection
MI
Poor medication compliance
what are 5 clinical manifestations for HHS?
Weakness and leg cramps
Reduced GCS, confusion, lethargy, headache, seizure
polyuria/oliguria + polydipsia
Nausea, Vom ,abdo pain
Dehydration - tachy, hypotension, dry
what are the four 1st line investigations for HHS
Serum/urine glucose
U+Es
ABG
Blood/urinary ketones
what is the gold standard test for HHS?
serum osmolality - raised
How can serum osmolarity be calculated?
2(Na+) + Glucose + Urea
what is the diagnostic criteria for HHS?
Hyperglycaemia >30 mmol/L
Hyperosmolality >320 mOsmol/Kg
Hypovolaemia
NO hyperketonaemia
NO acidosis (pH >7.3, Bicarb >15)
what is the management for HHS?
1st line - fluid replacement (0.9% saline), potassium replacement if low
adjuncts - LMWH, restore electrolyte loss, insulin if needed
when should insulin be given in HHS?
only IF blood glucose stops falling with IV fluids alone
How slowly should plasma sodium fall in HHS?
no quicker than 10 mmol/24 hours
How quickly should plasma glucose fall in HHS?
4-6 mmol/hour
what are 4 complications of HHS?
CV - VTE, arrythmias, MI
Neuro - stroke, seizure
Renal - AKI
Iatrogenic - cerebral oedema/cerebral pontine myelinolysis
what are 5 causes of hyperthyroidism?
Grave’s disease (most common)
Toxic multinodular goitre
Thyroiditis
Thyroid cancer
subacute thyroiditis (granulomatous or De Quervain’s)
what are 8 risk factors for hyperthyroidism?
female
post-partum
60+
FHx
autoimmune diseases
radiation
lithium therapy
smoking
What are 5 symptoms of hyperthyroidism?
Heat intolerance/sweating
palpitations/tremor
irritability
menstrual irregularities/sexual dysfunction
Goitre
what are 5 signs of hyperthyroidism?
orbitopathy (Grave’s)
cardiac flow murmur (thyroid bruit)
scalp hair loss
acropachy (Grave’s)
weight loss
what is the gold standard investigation for hyperthyroidism?
serum free total T3/4
what are 3 investigations for hyperthyroidism?
TSH - high/low
TSH receptor antibodies - present in Graves
Serum free/total T3/T4 - high
what are 6 causes of primary hyperthyroidism?
Graves - most common
Toxic multinodular goitre
Toxic adenoma
Subclinical hyperthyroidism
Thyroiditis - de quervains, hashimotos, post partum
Drugs - amiodarone, lithium
what is toxic multinodular goitre?
Several autonomously functioning thyroid gland nodules resulting in hyperthyroidism - often benign but can be malignant
what are 3 causes of secondary hyperthyroidism?
Pituitary adenoma - secreting TSH
Ectopic tumour - hCG secreting tumour (choriocarcinoma)
Hypothalamic tumour
what is hypokalaemia?
serum potassium <3.5 mol/L
what is mild hypokalaemia?
3.0-3.5 mmol/L
what is moderate hypokalaemia?
2.5-3.0 mmol/L
what is severe hypokalaemia?
<2.5 mmol/L
what can cause hypokalaemia? (7)
Excessive losses - D+V, high output stoma, dialysis, burns
Reduced intake
Malabsorption
Diuretics - loop and thiazide diuretics
Insulin
Salbutamol
Metabolic alkalosis - increased pH causes increased activity of H+/K+ antiporter operating to correct alkalosis
what are 5 risk factors for hypokalaemia?
older age
Medications - salbutamol, loop and thiazide diuretics, insulin
Co-morbidities - diabetes, renal disorders
poor dietary intake
Cushing’s syndrome
what are 7 clinical manifestations of hypokalaemia?
Muscle weakness, cramps and pain
Hypotonia
Fatigue
Palpitations
Constipation - due to reduced peristalsis
Reduced deep tendon reflexes
what is seen in ECG in Hypokalaemia/
U waves - extra wave after T wave
Small/absent/inverted T waves
Prolonged PR interval
ST depression
long QT
U have no Pot and no T but a long PR and a long QT
what is one important medication side effect in hypokalaemia?
Increases risk of digoxin toxicity - take care with diuretics
does hypokalaemia tend to be associated with acidosis or alkalosis?
Alkalosis - low potassium causes influx of H+ ions into cells to allow K+ to leave cells and enter serum
what are 4 causes of hypokalaemia with alkalosis?
Vomiting
thiazide and loop diuretics
Cushing’s syndrome
Primary hyperaldosteronism
what are 3 causes of hypokalaemia with acidosis?
diarrhoea
renal tubular acidosis
acetazolamide
Partially treated DKA
what other electrolyte deficiency is associated with hypokalaemia?
hypomagnesaemia
what is the management of hypokalaemia?
Mild-moderate (>2.5) - Oral potassium replacement - Sando-K
Severe (<2.5) - IV potassium - 20-40mmol K+ in 0.9% NaCl
what is the fastest you can replace potassium peripherally IV?
10 mmol per hour
e.g 40 mmol in 1L of saline bag ran over 4 hours fastest