The case of the GP under pressure Flashcards
primary and secondary hypertension - what is the difference?
Primary - essential or idiopathic HTN
Secondary - Renal, endocrine, other (e.g. pregnancy, drugs)
Secondary Hypertension causes - CHAPS
Cushings
Hyperaldosteronism
Aortic coarctation
Pheochromocytoma
Stenosis of Renal Arteries
Secondary Hypertension causes - CHAPS
Cushings
Hyperaldosteronism
Aortic coarctation
Pheochromocytoma
Stenosis of Renal Arteries
Pheochromocytoma
Adrenal medullary tumour that secretes excess catecholamines (Adrenaline, noradrenaline and dopamine from chromaffin cells - sometimes called intra-adrenal paraganglioma)
Paraganglioma
Neuroendocrine tumours that arise from sympathetic and parasympathetic ganglia, tumours of sympathetic ganglia have the ability to secrete excess catecholamines
The distinction between Pheochromocytoma and …. is an important one because of implications for associated neoplasms, risk for malignancy, and genetic testing.
The distinction between Pheochromocytoma and Paraganglioma is an important one because of implications for associated neoplasms, risk for malignancy, and genetic testing.
The distinction between … and Paraganglioma is an important one because of implications for associated neoplasms, risk for malignancy, and genetic testing.
The distinction between Pheochromocytoma and Paraganglioma is an important one because of implications for associated neoplasms, risk for malignancy, and genetic testing.
What is released when you have pheochromocytoma?
Too much adrenaline released from the adrenal gland
Common Pheochromocytoma and Paraganglioma Symptoms (classic symptoms - 3)
Classic Symptoms in 40%
- High BP
- Headache
- Sweating
Other symptoms include:
Flushing
Anxiety/panic
Palpitation
Abdo pain
Dizziness
etc
Case 1 - 58 YO man, developed hypertensive crisis during surgery for oral cancer
PMH: Hypertension and Ramipril
Developed anxiety and palpitation recently but put it down to recent diagnosis of oral cancer
Two nose bleeds in 10 years
Pheochromocytoma - Male vs Female
M=F
Pheochromocytoma - what decades of life?
3rd to 5th
Is pheochromocytoma rare?
Yes - investigate if clinically indicated
Pheochromocytoma: Paroxysms, ‘Spells’
10-60 min duration
Frequency - daily to monthly
Spontaneous
Precipitated Spells: diagnostic procedures, drugs, strenuous exercise, movement that increases intra-abdo pressure)
Pheochromocytoma: Hypotension
Hypotension occur in many patients
Mechanisms - loss of postural reflexes due to prolonged catecholamine stimulation
Pheochromocytoma: Features
N/V,
Hypercalcemia - associated MEN2, PTHrP secretetion by Pheo
Mild glucose intolerance
Lipolysis - weight loss and ketosis
Finish slide
Pheochromocytoma: Differentials
Hyperthyroidism
Arrhythmias
Hypoglycaemia
Migraine
Panic Attack
Alcohol Withdrawal
Recreational Drugs
Pheochromocytoma: Differentials
Hyperthyroidism
Arrhythmias
Hypoglycaemia
Migraine
Panic Attack
Alcohol Withdrawal
Recreational Drugs
Catecholamine synthesis and metabolism
Adrenaline - then others
Investigations - Pheochromocytoma
24hr work up
Finish slide
False positive - Pheochromocytoma
Finish slide
Imaging - Pheochromocytoma
What scan is this?
SPECT MIBG
blood pressure equation
blood pressure equation BP = CO x SVR
global prevalence of hypertension …% population
global prevalence of hypertension 22% population
how much of hypertension is primary? around …%
how much of hypertension is primary? around 90%
renal causes of secondary hypertension (3)
renal artery stenosis glomerulonephritis polycystic kidney disease
Endocrine causes of secondary hypertension (4)
renal causes of secondary hypertension
drugs causing secondary hypertension (5)
COCP NSAIDs steroids cocaine antidepressants
contributory factors to hypertension (6)
high BMI excessive salt excess alcohol lack of exercise stress caffeine
risk factors for hypertension(8)
male increasing age family history ethnicity smoker hyperlipidaemia diabetes low social status
Where is renin produced?
juxtaglomerular apparatus
what triggers renin production?
decreased renal perfusion
what does renin do?
converts angiotensinogen to angiotensin I
What converts angiotensin I to angiotensin II?
Angiotensin converting enzyme (ACE)
Where is ACE released from?
pulmonary epithelium
Action of Angiotensin II(3)
Vasoconstriction Release of aldosterone increased ADH secretion from pituitary
Where is aldosterone produced?
zona glomerulosa of adrenal cortex
action of aldosterone
increased tubular retention of sodium and water. lose potassium
Where does aldosterone act?
distal convoluted tubule and collecting duct
what causes hyperaldosteronism with low renin?
conn’s syndrome bilateral adrenal hyperplasia congenital adrenal hyperplasia
presentation of someone with high aldosterone to renin ratio …
presentation of someone with high aldosterone to renin ratio hypertension hypokalaemia normal/high sodium metabolic alkalosis
treating conn’s syndrome or adrenal hyperplasia?
laparoscopic adrenalectomy
treating conn’s syndrome or adrenal hyperplasia if bilateral disease
aldosterone antagonists e.g. spironolactone
what causes high aldosterone with high renin (4)
treating conn’s syndrome or adrenal hyperplasia if bilateral disease aldosterone antagonists e.g. spironolactone
presentation of someone with low aldosterone to renin ratio?
hypertension high creatinine
treatment for someone with a low aldosterone to renin ratio (4)
medical therapy renal angioplasty stent incision surgical repair
causes of renal stenosis (3)
atherosclerosis autoimmune phenomena genetic causes
complications of hypertension
atherosclerosis, strokes, CCF, CHD, LVH, renal failure, hypertensive retinopathy
acute target organ damage caused by hypertension
retinal haemorrhage stroke encephalopathy pulmonary oedema MI AKI aortic dissection
phaeochromocytoma - what is this?
adrenal medullary tumour that secretes excess catecholamines from chromaffin cells
List 3 catecholamines
dopamine, norepinephrine, epinephrine
paraganglioma
neuroendocrine tumour arising from sympathetic or parasympathetic ganglia
can paragangliomas secrete catecholamines?
yes if arise from sympathetic ganglia
primary hypertension
high blood pressure with no known cause
secondary hypertension
secondary hypertension high blood pressure caused by the effects of another disease
classic triad of phaeo symptoms
classic triad of phaeo symptoms high blood pressure headache sweating
high blood pressure headache sweating = classic triad of…
Phaeochromocytoma
other symptoms of phaeochromocytoma (aside from sweating, headache, high BP)
Phaeochromocytoma
what are phaeo spells like?
symptoms appear for 10-60mins, can be spontaneous or precipitated
What can precipitate a spell of phaeo symptoms?
invasive procedures drugs strenuous exercise micturition
how can phaeos cause postural hypotension?
loss of postural reflexes due to prolonged catecholamine stimulation
how can phaeos cause hypercalcaemia ?
can secrete PTH related protein which acts in same way
phaeos impact on lipids and glucose
causes lipolysis and glucose intolerance
when should you investigate for phaeos?
HTN at a young age incidentaloma found resistant HTN HTN crisis
usual age of phaeo presentation
30-50
differentials for pheochromocytoma?
hyperthyroidism arrythmias hypoglycaemia panic attack alcohol withdrawal
zones of adrenal cortex
zona glomerulosa, zona fasciculata, zona reticularis
What does the zone glomerulosa secrete?
mineralocorticoids (aldosterone)
what does zone fasciculata secrete?
glucocorticoids (cortisol)
what does zona reticularis secrete?
androgens
how is noradrenaline converted to adrenaline?
PNMT enzyme (phenylethanolamine N-methyltransferase)
what does PNMT enzyme need to function?
presence of cortisol
why is adrenaline the only catecholamine not released by paragangliomas?
no cortisol present so PNMT can’t work
1st investigations for PPGL
urinary and plasma metanephrines
what should you do if metanephrines slightly raised
repeat test if still elevated clonidine suppression test
Clonidine suppression test Used to test for …
pheochromocytoma Clonidine is an anti-hypertensive agent that is a central alpha-2 receptor agonist so should lower BP
reasons for falsely elevated metanephrines? (4)
paracetamol cocaine caffeine chocolate
imaging for phaeos (3)
CT MRI MIBG
MIBG scan
nuclear medicine scan that detects neuroendocrine tumours
pre-op treatment for pheochromocytoma ?
alpha adrenergic blockers beta blocker if patient tachycardic CCB
how long is the pre-op treatment for phaeos?
7-14 days, also high sodium diet and fluid intake
Familial Pheochromocytoma
Familial Pheochromocytoma hereditary cause of tumours
syndromes associated with phaeochromocytomas
MEN2 von-hippel-lindau NF1 mutation SDHD mutation
SDHD
SDHD a protein that if mutated can cause paragangliomas or phaeos
surgery for pheochromocytoma
surgical excision of tumour, can be partial or total adrenalectomy
indications for genetic screening with phaeos
bilateral tumours paraganglioma presence unilateral with family history young onset
