Hypertensive emergencies

Introduction

A hypertensive crisis is a severe and potentially life threatening increase in blood pressures (BP) which may result in an acute stroke, subarachnoid haemorrhage, seizures (hypertensive encephalopathy), heart attack, acute dissection of aorta, heart failure, renal damage or eclampsia (during pregnancy).

The underlying cause may be primary hypertension; however, secondary causes of hypertension must be excluded.

In adult patients this often occurs with a BP > 180/120 mmHg, while in children this may occur at lower BP levels.

These patients need careful examination to exclude target organ damage.

Rapid correction of blood pressure with careful monitoring to avoid a precipitous drop is indicated to prevent organ damage.

Symptoms of hypertensive emergencies

Headache
Chest pain
Shortness of breath
Nausea
Vomiting
Confusion
Seizures
Unconsciousness

Signs of hypertensive emergencies

The following are the signs of hypertensive emergencies

Severely elevated blood pressure (for age)
Unconsciousness
Seizures
Neck rigidity
Lung crepitations

Investigations

Chest X-ray
12-lead ECG
FBC
Urinalysis
Blood urea, electrolytes and creatinine
Brain CT scan (for stroke)
Chest CT scan with angiography (for suspected aortic dissection)
Cardiac enzymes: creatinine kinase-MB (CK-MB), serum aspartate transaminase (AST), serum lactic dehydrogenase (LDH) and troponins (for acute coronary syndrome) Echocardiography

Treatment for hypertensive emergencies

Objectives

The treatment objectives of hypertensive emergencies are:

To limit further organ-related complications by controlled reduction of BP
To control and subsequently prevent seizures if present
To manage identified target organ damage

Non-pharmacological treatment

Strict bed rest

Pharmacological treatment

Evidence Rating: [A]

Labetalol, IV,

Adults:

20-50 mg stat. (over a 2 minute period).
Repeat at 10 minute intervals, if necessary, to a max. of 200 mg

Children

12-18 years; 10-30 mg stat. (over a 2 minute period). Repeat at 15 minute intervals, if necessary (max. 200 mg)
1 month-12 years (by IV infusion); initially 500-1000 μg /kg body weight / hour adjusted at intervals of at least 15 minutes according to response. Max. 3 mg/kg/hour.

Note

Monitor BP every 5 minutes following each injection for all age groups.
Cease Labetalol injections if BP <140/90 mmHg and/or pulse <60 BPM in adults, (for children consult a paediatrician) or wheezing and bronchospasm occurs.

Hydralazine, IV,

Adults: 5-10 mg slowly (over a 2 minute period), diluted with 10 ml Normal Saline (0.9%).
Repeat at 20-30 minute intervals, if necessary