Hypertensive Emergencies

Presentation

This may be asymptomatic or may present with any of the many symptoms and signs of end-organ damage:

• Headache
• Fits
• Nausea and vomiting
• Visual disturbance
• Chest pain
• Neurological deficit
• Bleeding due to disseminated intravascular coagulopathy
• Microangiopathic haemolytic anaemia

(Thomas H. 2011)

Figure 1 - Hypertensive emergencies in children and adolescents
Source - www.netterimages.com

Causes

• Unilateral renovascular hypertension (Ex: renal artery stenosis)
• Renin-secreting neoplasms
• Trauma to the kidneys
• Renal vasculitis (Ex: scleroderma, polyarteritis andsystemic lupus erythematosus)
• Phaeochromocytoma
• Cocaine abuse
• Drugs such as monoamine-oxidase inhibitors, combined oral contraceptives or the withdrawal of alcohol, alpha stimulants such as clonidine, or beta-blockers.
• Sodium-volume overload and low renin levels (Ex: acute glomerulonephritis, primary aldosteronism)
• Pre-eclampsia/ eclampsia
• Hyperthyroidism
• Hypothyroidism

 (Thomas H. 2011)

Investigations

• Full history - including:

1. -       Past medical history
2. -       Full systems review
3. -       Drug history including over-the-counter, herbal remedies and recreational drugs

• Full examination - including:

1. -       Blood pressure measurements
2. -       Fundoscopy
3. -     Cardiovascular examination (look for signs of cardiac failure or pulmonary edema, carotid or renal bruits, left ventricular heave, cardiac murmurs, third or fourth heart sounds)

-       Neurological examination

• Blood tests:

1. -       FBC ± clotting screen
2. -       U&Es, creatinine
3. -       Liver and TFTs
4. -       Blood sugar measurement
5. -       ± Cardiac enzymes and fasting blood lipids

• ± Ambulatory blood pressure monitoring
• Urine dip testing for protein and blood
• CXR (cardiac size, cardiac failure, etc.)
• ECG (left ventricular hypertrophy or left atrial enlargement)
• Subsequent investigations may include:

1. -       CT/MRI scan of the head or kidneys
2. -       Plasma renin activity
3. -       Plasma aldosterone level
4. -       24-hour urine for vanillylmandelic acid (VMA) and catecholamine levels.
5. -       Auto-antibody levels (Ex: antinuclear factor)

 (Thomas H. 2011)

Stepwise Management

• Initially, try to reduce the mean arterial pressure by approximately 25% over the first 24-48 hours.
• An arterial line is helpful for continuous blood pressure monitoring.
• There may be severe sodium and volume depletion; volume expansion with isotonic sodium chloride solution may be required.
• Drugs

-       Intravenous route is usually used. Nitroprusside is the most commonly used IV drug.

-       Phentolamine is the drug of choice for a phaeochromocytoma crisis.

 (Thomas H. 2011)

REFERENCES

Thomas H. 2011. Patient.co.uk. [ONLINE] Available at: http://www.patient.co.uk/doctor/hypertensive-emergencies [Accessed 27^th April 15].