Hypertension - Investigations and treatment Flashcards
What tests can you use to show signs of high blood pressure
A sphygmomanometer
ECG (LVH)
Urine dipstick (haematuria and proteinuria)
Bloods: FBC, LFTs, U&Es, creatinine, serum urea, cGFR, lipid levels and glucose
What is Ambulatory blood pressure monitoring (ABPM)
Blood pressure measured over a 24 hrs period during everyday life
How do you confirm hypertension
Use clinical blood pressure readings initially and then confirm with ambulatory blood pressure monitoring (ABPM)
How do you stage blood pressure
systolic Diastolic
Normal <120 <80
Pre-hypertension 120-139 80-89
Stage 1 140-159 90-99
Stage 2 160-179 100-109
Severe <180 >110
What do you need to do after hypertension has been confirmed
assess for end organ damage
Screen for treatable causes (secondary hypertension)
What is the recommended BP target to achieve?
<135 /80-85
What approach is taken in management of hypertension
A stepped approach (4 steps) that uses low doses of several drugs
Why is a stepped approach used in treating hypetension
It minimises adverse events and maximises patient compliance.
What 2 factors determine the treatment at each step
If >55 years old or Africo-Caribbean (low renin)
What drugs types are used in treatment of hypertension
ACE inhibitor
Angiotensin II antagonists
Calcium channel blocker
Thiazide-type diuretic
Name 2 common ACE inhibitors used
Ramipril
Perindopril
What do ACE inhibitors do
Block the conversion of angiotensin I to angiotensin II
Angiontensin II is a potent vasoconstrictor
When do you not use ACE inhibitors (contraindications)
Renal artery stenosis
Renal failure
Hyperkalaemia (high K)
What are adverse drug events from ACE inhibitors
Cough (main one + common) first dose hypertension Taste disturbance Renal impairment Angioneutrotic oedema
When should you not give ACE inhibitors
if the patient is pregnant (its teratogenic)
If patient is on NSAIDs (causes acute renal failure)
If taking potassium supplements or potassium sparing diuretics (hyperkaelimia)
What do angiotensin II antagonists do
blocks the actions of angiotensin II at the angiotensin AT1 receptor
What are 4 angiotensin II antagonists
Valsartan
Irbesartan
Losartan
Candersartan
What is the main advantage of giving angiotensin II antagonists over ACE inhibitors
DOESNT GIVE A COUGH
but not as effective
What do Calcium channel blockers do
They block the L-type calcium channels thereby relaxing the large and small arteries and reduces peripheral resistance. They have selectivity between vascular and cardiac L-type channels)
What are 2 vasodilator Calcium channel blockers
Amlodopine
Felodopine
What are 2 rate limiting calcium channel blockers
Verapamil
Diltiazem
When do you use CCB and why?
STEP 1 - When patient is >55 years old
- If a woman is of child baring age
STEP 2 - in <55 years old
Compliance is high and theres a benefit in elderly patients with systolic hypertension
What are contraindications of CCB
Acute MI
Heart failure
Bradycardia
What are ADRs of CCB
flushing headeache ankle oedema indigestion and reflux Oesophagitis
How do Thiazide type diuretics work
They block reabsorption of sodium and enhance urinary sodium loss. (the full effects may take weeks)
What are two common thiazide type diuretics
Indapamide
Clotralidone
When are thiazide type diuretics used
Used in pregnancy
Commonly used in step 1 in mild/moderate hypertension in afro-carib
Can be used in combination with any other anti-hypertensive agent
What is a ADR with thaizide type diuretics
Gout and impotence (rare)
What are some less common hypertensive agents
Alpha adrenoreceptors antagonists - Doxazosin
Centrally acting agents - Methyldopa and Moxonidine
Vasodilators - Hydralazine, Minoxidil
