Measuring blood pressure

•Use the correct size cuff. The width of the cuff should be at least 40% of the arm circumference. The bladder should be centered over the brachial artery, and the cuff applied snugly. Support the arm in a horizontal position at mid-sternal level. Inflate the cuff while palpating the brachial artery, until the pulse disappears. This provides an estimate of systolic pressure.

Inflate the cuff until 30mmHg above systolic pressure, then place stethoscope over the brachial artery. Deflate the cuff at 2mmHg/s.

• Systolic pressure: The appearance of sustained repetitive tapping sounds•Korotkoff I).

• Diastolic pressure: Usually the disappearance of sounds (Korotkoff V). -However, in some individuals (eg pregnant women) sounds are present until the zero-point. In this case, the muffling of sounds, Korotkoff IV, should be used.

Arterial hypertension classification according to level of BP (WHO, 1996):

Type	Systolic BP (SBP, mm Hg)	Diastolic BO (DBP, mm Hg)
Normal BP	<140	<90
I. Mild hypertension	140-159	90-99
- boundary	140-149	90-94
II. Moderate hypertension	160-179	100-109
III. Severe hypertension	≥ 180	≥ 110
Isolated systolic hypertension	> 140	< 90
Boundary isolated systolic hypertension	140-149	< 90

Systolic hypertension in the elderly: The age-related rise in systolic BP was considered part of the 'normal' ageing process, and isolated systolic hypertension (ISH) in the elderly was largely ignored. But evidence from 3 major studies indicates, beyond doubt, that benefits of treating are even greater than treating moderate hypertension in middle-aged patients.

‘Malignant' hypertension: This refers to severe hypertension (eg systolic >200, diastolic >130mmHg) in conjunction with bilateral retinal haemorrhages and exudates; papilloedema may or may not be present. Symptoms are common eg headache ± visual disturbance. Alone it requires urgent treatment. However, it may precipitate acute renal failure, heart failure, or encephalopathy which are hypertensive emergencies. Untreated, 90% die in 1yr; treated, 70%: survive 5yrs. Pathological hallmark is fibrinoid necrosis. It is more common in younger patients and in Blacks. Look hard for any underlying cause.

Risk factors

Family history, race (most common in blacks), stress, obesity, a high intake of saturated fats or sodium, use of tobacco, sedentary lifestyle, and aging are risk factors for essential hypertension.

Causes of the secondary hypertension -5% of cases:

1. Renal disease: The most common secondary cause. 3/4are from intrinsic renal disease:

- glomerulonephritis,

- polyarteritis nodosa (pan),

- systemic sclerosis,

- chronic pyelonephritis, or polycystic kidneys.

1/4 are due to renovascular disease:

- most frequently atheromatous (elderly male cigarette smoker; eg with peripheral vascular disease)

- rarely fibromuscular dysplasia; (young female).

2. Endocrine disease:

- Cushing's syndromes

- Conn's syndromes

- Phaeochromocytoma

- Acromegaly

- Hyperthyreoidism

- Hyperparathyroidism.

3. Coarctation of the aorta

4. Pregnancy;

5. Neurologic disorders;

6. Use of oral contraceptives or other drugs, such as cocaine, epoetin alfa, and cyclosporine, steroids.

Дата добавления: 2015-10-29