Hypertension & Hypertensive Emergencies Flashcards
what are the 3 stages of hypertension
- stage 1: clinical BP > 140/90mmHg or ABPM >135/85mmHg
- stage 2: clinical BP >160/100mmHg or ABPM >150/95mmHg
- severe: clinical systolic >180mmHg or clinical diastolic >110mmHg
what are the symptoms of HTN
- nil or headache
- sweating, headache, palpitations or anxiety –> phaechromocytoma
- muscle weakness or tetany –> hyperaldosteronism
what are you looking for in a history of HTN
- PMHx: angina, CCF, palps, syncope, valvular heart disease
- FHx: HTN, permature coronary disease, PKD
- DHx: prior anti-HTN, drug intolerances
what are you looking for on physical assessment for HTN
look for secondary causes
- Cushing’s syndrome
- PCK enlarged kidneys
- renal bruit
- radio-femoral delay (coarctation)
what are the 2 broad categorisations of HTN
- essential: 90% aka primary HTN
- secondary
what are the secondary causes of HTN
ROPED
- Renal disease: renal artery stenosis
- Obesity
- Pre-eclampsia
- Endocrine: hyperaldosteronism Conn’s syndrome
- Drugs e.g. alcohol, steroids, NSAIDs, oestrogen
how can renal artery stenosis be diagnosed
duplex USS
MR/CT angiogram
what are appropriate investigations into HTN
- protein in urine: send urine sample for estimation of albumin:Cr ratio
- haematuria using reagant strip
- blood sample: plasma glucose, electrolytes, Cr, eGFR, serum total and HDL cholesterol
- examine fundi for hypertensive retinopathy
- 12 lead ECG
- consider echo for LVH, valve disease/LVSD or diastolic dysfunction
what should be done whilst watiing for confirmation of diagnosis of HTN
- evidence for target-organ involvement
- CVS risk assessment (qrisk)
when should treatment for stage 1 HTN be offered
in those under 80:
- evidence of target organ damage
- established CVD
- renal impairment or diabetes
- Qrisk >20%
what is the target BP for patients with diabetes, previous stroke, IHD, CKD
< 130/80
what is a QRISK score
estimates the percentage risk that a patient will have a stroke or myocardial infarction in the next 10 years
When the result is above 10%, they should be offered a statin, initially atorvastatin 20mg at night
what is the non-pharmacological treatment of HTN
- weight reduction if BMI>25
- moderate salt intake
- minimise alcohol
- aerobic exercise
- smoking cessation
what is the pharmacological step by step management of HTN
Step 1: Aged under 55 or type 2 diabetic of any age or family origin, use A. Aged over 55 or Black African use C
Step 2: A + C. Alternatively, A + D or C + D
Step 3: A + C + D
Step 4: A + C + D + fourth agent
- serum K <4.5mmol/L - spironolactone
- serum K >4.5 mmol/L: doxazosin or atenolol
A – ACE inhibitor (e.g., ramipril)
B – Beta blocker (e.g., bisoprolol)
C – Calcium channel blocker (e.g., amlodipine)
D – Thiazide-like diuretic (e.g., indapamide)
ARB – Angiotensin II receptor blocker (e.g., candesartan)
how does spironolactone work
potassium sparing diuretic which works by blocking the action of aldosterone in the kidneys
- sodium excretion and potassium reabsorption
- helpful when thiazide diuretics casues hypoK
monitor U&Es as can cause hyperkalaemia
what are the complications of high BP
- Ischaemic heart disease (angina and acute coronary syndrome)
- Cerebrovascular accident (stroke or intracranial haemorrhage)
- Vascular disease (peripheral arterial disease, aortic dissection and aortic aneurysms)
- Hypertensive retinopathy
- Hypertensive nephropathy
- Vascular dementia
- Left ventricular hypertrophy
- Heart failure
a patient with HTN has developed LVH - what could you expect to find on examination
- sustained and forceful apex beat
- seen on an ECG using voltage criteria
- best diagnosed with an echo
how often do the NICE guidelines recommend monitoring BP
every 5 years to screen for HTN and every year in T2DM
what BP readings would require 24-hr ABPM
clinic BP 140/90 - 180/120mmHg
what is accelerated HTN aka malignant HTN
extremely high BP > 180/120 + retinal haemorrhages or papilloedema
what is the management for patients with accelerated HTN
- same day referral
- fundoscopy exam
- assess for secondary causes and end-organ damage
what is a hypertensive crisis
an increase in BP which if sustained over the next few hours will lead to irreversible end-organ damage i.e. encephalopathy, LV failure, aortic dissection
what are the 2 main presentations of a hypertensive crisis
- emergency: high BP associated w critical event e.g. encephalopathy, pulmonary oedema, acute kidney injury, myocardial ischaemia
- urgency: high BP without a critical illness, but may include ‘malignant hypertension’: associated with grade 3/4 hypertensive retinopathy
what is the aim of therapy in a hypertensive crisis
reduce the diastolic BP to 110 mmHg in 3 - 12 hours (emergency) or 24 hours (urgency).
what are IV treatment options in a hypertensive emergency
- Sodium nitroprusside
- Labetalol
- GTN (1 - 10 mg/hr)
- Esmolol acts within 60 seconds, with a duration of action of 10 - 20 minutes. Typically, the drug is given as a 0·5 - 1 mg/kg loading dose over 1 minute, followed by an infusion starting at 50 µg/kg/min and increasing up to 300 µg/kg/min as necessary
what are the oral treatment options for hypertensive emergency
- amlodipine 5-10mg OD
- diltiazem 120-300mg OD
- lisinopril 5mg OD
- combination of ACEi/calcium antagonist effective and well tolerated
what is the most effective treatment regimen for patients with hypertensive urgency
nifedipine 20mg MR BD + amlodipine 10mg OD for 3 days the continue with amlodipine 10mg OD after
what is the classic triad of symptoms of phaemochromocytoma
- episodic headache
- sweating
- tachycardia
what is the most common sign of phaeochromocytoma
sustained or paroxysmal hypertension
how is diagnosis of phaeochromocytoma confirmed
main test is 24hr urine collection
- measurements of urinary and plasma fractionated metanephrines and catecholamines
- CT/MRI scan of abdomen-pelvis may detect adrenal tumours
what is the management once phaeochromocytoma is diagnosed
surgical resection
how is HTN controlled pending surgery for phaeochromocytoma
combined alpha/beta adrenergic blockade
- phenoxybenzamine most commonly used; inital dose 10mg OD/BD then the dose is increased by 10-20mg in divided doses every 2-3 days as needed
- final dose is typically 20-100mg daily
After adequate alpha-adrenergic blockade has been achieved, beta-adrenergic blockade is initiated, which typically occurs two to three days preoperatively. The beta-adrenergic blocker should never be started first
in the case that phenoxybenzamine is not tolerated for phaeochromocytoma, what can be used instead
CCB - nicardipine
what are appropriate tests/investigations to diagnose Cushing’s
- bloods may show hyperglycaemia
- 24hr urine cortisol excretion will be elevated (diurnal
- low dose dexamethasone suppression test
- adrenal CT indicated
what are appropriate tests/investigations to diagnose primary hyperaldosteronism
suspect this diagnosis if low serum K and high/normal Na (but in up to 50%, K is normal)
- consider in pt w hypoK and in pt w resistant HTN or FHx of premature HTN
- aldosterone:renin ratio in morning ( ratio is typically > 20-30)
- Plasma renin activity is typically very low or undetectable in patients with primary aldosteronism, and the plasma aldosterone concentration high
- investigated by hypertension specialists or endocrinologists as confirmatory testing will be required
- adrenal CT
what are the features of hypertensive retinopathy
- flame shaped haemorrhages
- papilloedema (optic disc swelling)
