Hypertension & Hypotension Flashcards Preview

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Flashcards in Hypertension & Hypotension Deck (23):
1

Name the 5 main types of hypertensives

Angiotensin converting enzyme inhibitor (ACEi)
Angiotensin II Receptor Blocker (ARB)
Beta adrenoreceptor blockers (B Blocker)
Ca channel blocker (CCB)
Thiazides

2

What's the treatment for hypertension in patients <55?

1. ACEi/ARB/B Blocker
2. Add CCB/thiazides
3. CCB + thiazide
4. High dose thiazide/spironolactone or alpha Blocker

3

What's the treatment for patients >55 or of afro-Caribbean descent?

1. CCB/ Thiazides
2. ACE/ARB

4

What are the effects of ACEi

Vasodilation
Reduce afterload
Reduced BP
Reduces aldosterone (increased Na+, H20 secretion)

5

Side effects of ACEi

Persistent dry cough
Hypotension
Hyperkalaemia
NSAIDs used in conjunction with ACEi increase RF risk
Stop medication if patient is in renal failure, has an AKI or renal artery stenosis

6

Examples of ACEi

Ramipril. Max 10mg, initial 2.5mg OD

Lisinopril: Max 80mg, initial 2.5

Perindopril:

7

Mechanism of action for B blockers

Blocks B1 adrenergic receptors:
In SAN has negative chronotrophic effect

In myocardium has negative ionotrophic effects (decreases force of contraction)

8

Side effects of B Blocker

Bronchospasm
Fatigue
Cold extremities
Headaches
GI disturbance
Sleep disturbance

Contraindication: Asthmatic

9

Examples of B Blockers

Atenolol: 25-50mg daily
Propanolol: 40mg OD to TD
Metoprolol: IVI max 15mg oral 50-200 mg
Bisoprolol: 10mg daily max. Long term

10

Mechanism of ARB

Blocks binding of angiotensin II to angiotensin I receptors

11

Examples of ARB

Losartan (Cozaar)
Candesartan (Atacand)
Valsartan (Diovan)
Olmesartan (Olmetec)

12

Examples of Calcium channel blockers

Dihydropyridines (Nifedipine and Amlodipine)
Nondihydropyridines (Verapamil and diltiazem)

13

CCBs mechanisms of action

Prevent calcium entering the heart and blood vessels walls. Thereby preventing contraction and relaxing the heart and blood vessels to relieve BP

14

Uses of CCB

HTN, Angina, Raynaud's, AF (nondihydropyridines)

15

Isolated systolic HTN

Elevated systolic reading (>160 mmHg, 140mmHg-159 bordeline,) with a normal diastolic reading (<90mmHg)

16

Common causes of secondary hypertension

Vascular
Renal artery stenosis
Coarctation of aorta
Pre-eclampsia

Renal
CKD
Glomerulonephritis
Nephrotic syndrome
Obstructive uropathy
Polycystic kidney disease

Endocrine
Phaeochromocytoma
Hyperaldosteronism
Cushings
Hyper/Hypothyroidism
Hyperparathyroidism

17

Orthostatic/postural hypotension

Systolic BP drop off at least 20mmHg or diastolic BP drop of at least 10mmHg within 3 minutes of standing

18

Pathophysiology of orthostatic hypotension

When an otherwise healthy person stands, about 700 mL of blood pools in the leg veins and the lower abdominal veins. Venous return to the heart decreases, resulting in a transient decline in cardiac output. This leads to baroreflex-mediated sympathetic activation with an increase in cardiac stroke volume and peripheral vasoconstriction, as well as parasympathetic withdrawal with an increase in heart rate. These rapid haemodynamic changes prevent blood pressure from falling.

Failure of these mechanisms causes orthostatic hypotension.

19

Typical presentation of orthostatic patient

Light headed, dizzy, weak, faintness, dimming of vision usually doesn't occur supine.

Parkinsonian features

Cerebellar ataxia from multisystem atrophy (MSA or Shy-Drager syndrome). Ataxia of gait and speech is the most common for MSA

Resting tachycardia-sign of diabetic loss of parasympathetic

Abnormal GI, erectile dysfunction-Autonomic neuropathy

20

What may elicit orthostatic hypotension

Early in the morning (because of relative volume depletion after overnight fast and pressure diuresis)

In hot environments (because of cutaneous vasodilation)

After meals (because of splanchnic blood pooling)

After standing motionless (because of decreased venous return caused by loss of muscle pump action)

After exercise (because of metabolic vasodilation).

21

Common causes of orthostatic hypotension

In elderly:
Anti-hypertensives
Alpha-blockers
Diuretics
TCA
Prolonged bed rest resulting in physical deconditioning

Diabetes and amyloidosis cause autonomic neuropathy

Parkinson's disease with lewy body dementia
Multiple system atrophy (MSA) commonly have cerebellar ataxia resulting in ataxia of speech and gait

22

Management of orthostatic hypotension

Lifestyle
Fludrocortisone and NaCl (volume expansion)
Midodrine (presser)
Droxidopa (noradrenaline)

23

Causes of shock

Cardiogenic: after myocardial infarction, due to cardiomyopathy, valvular abnormalities, or arrhythmias. (pump dysfunction)

Hypovolemic: haemorrhages, burns, GI loss, heat stroke

Distributive (failure of vasoregulation)

Obstructive: PE, cardiac tamponade, tension pneumothorax