Managing Hypertensive Emergencies

Hypertension is a common condition, affecting approximately 1 in 3 adults. Although usually asymptomatic, it requires chronic treatment to prevent long-term complications, such as stroke, myocardial infarction, chronic kidney disease and vascular dementia. In its more severe forms, it requires acute measures to prevent more immediate hypertension-mediated organ damage; however, the details of such measures will vary depending on the precise presentation. Patients with blood pressure readings ≥180/120 mmHg should be referred to hospital for a same-day assessment, when features suggestive of acute end organ damage or suspicion of phaeochromocytoma are present; in such cases (“hypertensive emergency”), treatment should be commenced with parenteral antihypertensive medication (such as intravenous labetalol, glyceryl trinitrate, hydralazine or nicardipine), with intra-arterial blood pressure monitoring in a critical care setting. Oral antihypertensive treatment should be started at the same time, with a view to weaning off parenteral therapy when the blood pressure allows. If no symptoms or features of acute end organ damage are present despite similar blood pressure readings (“hypertensive urgency”), patients should be commenced on oral antihypertensive medication, and the blood pressure should be rechecked within one week. All such cases should undergo screening for possible secondary causes, including primary aldosteronism and phaeochromocytoma. In the context of acute ischaemic stroke, blood pressure when high should not be reduced in the short term, because of the danger of extending the infarct zone, unless the patient is a candidate for thrombolysis or, where thrombolysis is not a consideration, the patient has evidence of hypertensive emergency. By contrast, in acute haemorrhagic stroke, the blood pressure when high should be reduced quickly, because of the danger of haematoma expansion, although a close eye should be kept for evidence of cerebral hypoperfusion. Whatever the stroke aetiology, tight long-term blood pressure control should be aimed for (clinic systolic blood pressure < 130 mmHg, home systolic blood pressure < 125 mmHg). In patients presenting with severe hypertension in pregnancy, including pre-eclampsia, treatment should always be performed in conjunction with obstetricians or obstetric physicians where these are available. Drugs used to treat severe hypertension include oral labetalol or nifedipine, or, as a third-line option, methyldopa. If the blood pressure continues to rise and there are signs of impending target organ damage or eclampsia, intravenous labetalol should be administered, with intra-arterial blood pressure monitoring in a critical care setting. In conclusion, very high blood pressure is a common presentation in the Emergency Department, but treatment is very context-specific and does not depend purely on the blood pressure readings. The hypertension team should be involved at an early stage where there is any doubt as to how to manage these patients, as well as for continuing investigation, treatment and follow-up.