ILA Hypertension Flashcards
What BP readings are classed as hypertension?
Clinic BP ≥ 140/90 mmHg
or
ABPM ≥135/85 mmHg
What are the important aspects of clinical examination for hypertension?
- Fundoscopy - for hypertensive retinopathy
- Signs of secondary hypertension - palpable kidneys, abdominal bruit, neurofibromas, radiofemoral delay
- Signs of end organ damage - ECG (LVH), proteinuria
What investigations would you do for hypertension?
Clinic BP
And to confirm BP:
Ambulatory BPM - ABPM - At least 2 measurements per hour taken during waking hours and use the average value to confirm diagnosis
Home BPM - used if pt cannot tolerate ABPM, record BP 2 times twice a day when seated at least 1 min apart for 4-7 days, discard, Discard the measurements from the first day and use the average of all the remaining measurements
Urinalysis - for blood and protein (hypertensive nephropathy and GN can be a cause of secondary hypertension)
24 hour urine metanephrine: phaeochromocytoma
urinary free cortisol: Cushing’s
U+E: K+ reduces in Conn’s
renin and aldosterone levels: for Conn’s - hyperaldosteronism
Abdo USS - PKD
MRI aorta - for coarctation
What are the three stages of hypertension and what would the clinic and ABPM readings be for each of these?
clinic, ABPM
Stage 1 - ≥140/90, ≥135,85
Stage 2 - ≥160/100, ≥150/95
Stage 3 - >180/110
What do stages 1, 2 and 3 mean in terms of treatment?
Stage 1 - consider treatment
Stage 2 - treat
Stage 3 - Immediate treatment
What is essential hypertension?
Same as primary hypertension
aetiology unknown
Secondary hypertension is more common than primary hypertension. T or F?
False -primary hypertension is 95% of cases
When should you consider secondary hypertension?
In a younger pt
Resistant BP
When there are signs of an underlying cause
What are the main causes of secondary hypertension?
CHAPS Cushing's Hyperaldosteronism (Conn's) Aortic coarctation Phaeochromocytoma Polycystic kidneys Stenosis of the renal arteries
Apart from CHAPS, what are the other possible causes of secondary hypertension?
OCP Cocaine and amphetamines Pregnancy Acromegaly Steroids
What findings on examination would you get for the main causes of secondary hypertension?
CHAPS
Cushings - central obesity, moon face, buffalo hump, red striae, hirsutism
Hyperaldosteronism (Conn’s) - arrythmia, hypokalaemia
Aortic coarctation: radio-femoral delay
Phaeochromocytoma - skin stigmata of neurofibromatosis: cafe au lait spots, neurofibromas
Polycystic kidneys - palpable kidneys
Stenosis of the renal arteries - abdominal bruit
What is the non-pharmacological treatment of essential hypertension?
- diet - high fruit and veg and low fat
- regular physical exercise
- reduction of alcohol intake
- reduction of dietary sodium intake (5-6g per day)
- smoking cessation
- weight reduction
When would you offer antihypertensives to someone with stage 1 hypertension?
If they are under the age of 80 and they have one of:
- target organ dmanage - retinopathy, nephropathy
- established CVD
- renal disease
- diabetes
- 10 year CV risk as > 20%
If they are under 40, investigate for secondary hypertension
When would offer antihypertensives to someone with stage 2 hypertension?
You would offer antihypertensives to anyone with stage 2 hypertension
What are the BP targets for a patient under 80 yrs old?
Clinic BP ABPM
< 140/90 < 135/85
What are the BP targets for a patient over 80yrs old?
Clinic BP ABPM
< 150/90 < 145/85
What are the BP targets for a diabetic?
<130/80
Define the BP difference in the white coat effect
A discrepancy of more than 20/10 mmHg between clinic and average daytime ABPM or average HBPM blood pressure measurements at the time of diagnosis
How would you measure response to treatment in pts with white coat syndrome?
use ABPM or HBPM as an adjunct to clinic blood pressure measurements
How would you manage stage 3 hypertension?
start antihypertensives immediately before waiting for results of ABPH or HBPM and consider admission
Refer to specialist care on the same day if pt has:
• Accelerated (malignant) hypertension = this is a rapid rise in BP, BP > 180/110 mmHg and signs of papilledema and/or retinal haemorrhage. Pt may have symptoms of headache and/or visual disturbance. Requires urgent Tx
• Suspected pheochromocytoma
(I also put: Need to reduce BP slowly as may lead to cerebral, renal and retinal ischaemia or MI. BP response to therapy should be carefully monitored in a high dependency unit. Aim is to reduce the diastolic BP to 100mmHg over 24-48 hours, using oral meds such as amlodipine)
What are the antihypertensive treatment steps for hypertension?
Step 1:
under 55 - ACEI or ARB
over 55 or afrocarribean of any age - CCB
Step 2:
ACEI/ARB + CCB
Step 3:
ACEI/ARB + CCB + thiazide diuretic
Step 4 (resistant hypertension): Add spironolactone, high-dose thiazide, apha blocker, beta blocker
How do ACEIs work?
inhibit ACE (enzyme) which converts angiotensin I to angiotensin II
What does angiotensin II do?
5 roles:
1. Increases sympathetic activity
- Reabsorption of Na+ in the kidneys, result in in water retention
- Increases aldosterone production from the adrenal gland, which results in more reabsorption of Na+ in the kidneys, result in in water retention
- Arteriolar vasoconstriction and increase in BP
- Causes the posterior lobe of the pituitary to secrete ADH, which causes water reabsorption in the kidneys
(all acts in to increase perfusion of the juxtaglomerular apparatus)
What does renin do and where is it produced?
Secreted by the kidney to increase perfusion of the juxtaglomerular apparatus
Converts Angiotensinogen to Angiotensin I
Where is the enzyme ACE produced?
Surface of pulmonary and renal epithelium
Ie lungs and kidneys
What is the mechanism of action of spironolactone?
Aldosterone antagonist
what happens when there is less aldosterone?
More sodium and water excretion
