Blood pressure (HTN and hypotension)

Question 1

What causes orthostatic hypotension ?

Answer 1

Results from failure of Baroreceptor responses to gravitational shifts in blood, when moving from horizontal to vertical position

Question 2

Define what orthostatic hypotension is

Answer 2

This is a drop in SBP of at least 20 mmHg and/or a drop in DBP of at least 10 mmHg after 3 minutes of standing Think ‘3-2-1, drop’ - after 3 minutes of standing, a drop in at least 20 mmHg systolic or 10 mmHg diastolic

Question 3

What symptoms may orthostatic hypotension cause ?

Answer 3

light-headedness dizziness blurring of vision, fainting and falls ‘Symptoms resolve as blood pressure returns to normal (for example, on returning to a seated position). and not all experience symptoms’

Question 4

What are the causes of orthostatic hypotension?

Answer 4

It may be idiopathic OR may arise as a result of disorders affecting the autonomic nervous system (for example, Parkinson’s disease, multiple system atrophy or diabetic autonomic neuropathy), from a loss of blood volume or dehydration, or because of certain medications such as antihypertensives or alpha-blockers (e.g. for BPH). ‘On standing, gravity causes blood to pool in the lower extremities. The autonomic nervous system usually counteracts this by increasing heart rate, cardiac contractility and vascular tone.The skeletal muscle in the lower body also contracts to prevent excessive pooling.’

Question 5

What happens to the risk of CV mortality with every 20/10 increase in BP?

Answer 5

The risk doubles

Question 6

What is the normal range of BP ?

Answer 6

Between 90/60 and 140/90 mmHg.

Question 7

What 2 categories can the causes of hypertension be split up into?

Answer 7

1. Essential HTN - 90/95% of cases
2. Secondary HTN may be caused by a wide variety of endocrine, renal and other causes.

Question 8

What are the signs and symptoms of hypertension ?

Answer 8

Does not typically cause symptoms unless it is very high, for example > 200/120 mmHg.

If very raised patients may experience:

• headaches
• visual disturbance
• seizures

Question 9

List the renal causes of secondary hypertension

Answer 9

• Glomerulonephritis
• Chronic pyelonephritis
• Adult polycystic kidney disease
• Renal artery stenosis

Question 10

List the endocrine causes of secondary hypertension

Answer 10

• Primary hyperaldosteronism
• Phaeochromocytoma
• Cushing’s syndrome
• Liddle’s syndrome
• Congenital adrenal hyperplasia (11-beta hydroxylase deficiency)
• Acromegaly

Question 11

List the other causes of secondary hypertension besides renal & endocrine causes

Answer 11

• Glucocorticoids
• NSAIDs
• Pregnancy
• Coarctation of the aorta
• Combined oral contraceptive pill
• Intracranial tumour

Question 12

Define what essential hypertension is

Answer 12

This is a rise in BP (>140/90) of unknown cause

Question 13

Define what hypertension is

Answer 13

• A clinic reading persistently above >= 140/90 mmHg, or:
• A 24 hour BP average reading >= 135/85 mmHg

Question 14

How is HTN diagnosed ?

Answer 14

1. Firstly measure BP in clinic, if the first reading is > 140/90 then take a second reading (the lower reading determines further management)
2. Secondly diagnosis is then made using ABPM or HBPM (if ABPM declined or not tolerated)

Question 15

How is HTN classified ?

Answer 15

Stage 1 (mild) hypertension:

• Clinic BP is ≥ 140/90 and
• ABPM or HBPM daytime average is ≥ 135/85

Stage 2 (moderate) hypertension:

• Clinic BP is ≥ 160/100 and
• ABPM or HBPM daytime average is ≥ 150/95

Stage 3 (severe) hypertension:

• Clinic BP is ≥ 180 or
• Clinic diastolic BP is ≥ 110

Note for severe dont need to do ABPM/HBPM and treated is started immediately

Question 16

Why can you not rely on diagnosing HTN in clinic alone ?

Answer 16

Because of the subgroup of people with ‘white coat HTN’ - in these people there BP climbs by 20mmHg ==> people would be diagnosed with HTN when they actually have normal BP outwidth the clinic

Question 17

How is ABPM performed ?

Answer 17

Ambulatory blood pressure monitoring (ABPM):

• At least 2 measurements per hour during the person’s usual waking hours
• Use the average value of at least 14 measurements

Question 18

How is HBPM performed ?

Answer 18

Home blood pressure monitoring (HBPM)

• For each BP recording, two consecutive measurements need to be taken, at least 1 minute apart and with the person seated
• BP should be recorded twice daily, ideally in the morning and evening
• BP should be recorded for at least 4 days, ideally for 7 days
• Discard the measurements taken on the first day and use the average value of all the remaining measurements

Question 19

When can you not use a automated blood pressure machine ?

Answer 19

If the persons pulse is irregular ==> you need to always check their pulse before and if its irregular then you need to do it manually

Question 20

What is important to also asses in patients with newly diagnosed HTN?

Answer 20

Ensure they do not have any end-organ damage:

1. Fundoscopy: to check for hypertensive retinopathy
2. Urine dipstick: to check for renal disease, either as a cause or consequence of hypertension
3. ECG: to check for left ventricular hypertrophy or ischaemic heart disease
4. Take blood to measure glucose & HbA1c to check for DM, electrolytes, creatinine, eGFR, cholesterol
5. Estimation of CV risk to discuss prognosis and healthcare options

Question 21

What treatment should be provided to people with stage 1 HTN?

Answer 21

Lifestyle management:

1. A low salt diet is recommended, aiming for less than 6g/day, ideally 3g/day.
2. Caffeine intake should be reduced
3. Other general bits of advice remain: stop smoking, drink less alcohol, eat a balanced diet rich in fruit and vegetables, exercise more, lose weight

Note - those with stage 2 or 3 HTN should also be given this lifestyle management alongside anti-hypertensives

Question 22

When should patients with stage 1 HTN be offered more treatment than just lifestyle advice ?

Answer 22

Treat if < 80 y/o AND any of the following apply:

• Target organ damage
• Established CVD
• Renal disease
• Diabetes
• A 10-year cardiovascular risk equivalent to 10% or greater

This means starting them on anti-hypertensives

Question 23

When should treatment with anti-hypertensives generally be started ?

Answer 23

ABPM/HBPM >= 150/95 mmHg (i.e. stage 2 or worse) - offer drug treatment regardless of age

Question 24

When should anti-hypertensive treatment be started immediately after clinic measurement ?

Answer 24

If BP is ≥ 180/110 mmHg

Question 25

For patients with any stage of HTN who are < 40 y/o what should be considered?

Answer 25

Specialist referral to exclude secondary causes.

Question 26

What is the stepwise protocol for anti-hypertensive treatment of HTN?

Answer 26

1st line for those

OR 1st line for those > 55 or who are from afro-caribean origin = CCB (think C for carribean)

2nd line = if taking ACEi/ARB add either a CCB or thiazide diuretic. If already taking CCB add a ACEi or ARB (ARB preferred)

3rd line = ACEI/ARB + CCB + thaizide diuretic

4th line = if K+ < 4.5 add low dose spironolactone, if > 4.5 add alpha or beta blocker

Question 27

What are the 2 main options for controlling someone’s BP in hospital if PO anti-hypertensives have failed ?

Answer 27

Can consider IV labetalol or GTN infusion

Question 28

Define resistant HTN ?

Answer 28

This is HTn requiring 4th line treatment

Question 29

How often should patients with HTN have there BP monitored and what should the BP targets be?

Answer 29

Anually using clinic BP measurements, with targets of:

• 140/90 mmHg in people aged < 80
• 150/90 mmHg in people aged ≥ 80

For people with a ‘white-coat effect’ consider ABPM or HBPM as an adjunct to clinic BP to monitor response to treatment. Aim for ABPM/HBPM target average of:

• below 135/85 mmHg in people aged < 80
• below 145/85 mmHg in people aged ≥ 80