Approach to managing severely elevated blood pressure

Evidence to guide the management of severely elevated blood pressure (BP) is limited, so guidelines are based on current literature and expert consensus. The primary aim is to do no harm.

True hypertensive emergencies are uncommon, and rapid reduction of an elevated BP may cause more harm than good. Treatment must balance the risks of lowering BP too rapidly (eg renal, coronary or cerebral ischaemia) with those of persistent hypertension.

Note: Rapid reduction of an elevated blood pressure may cause more harm than good.

Provide patients who use a home BP monitor with a written plan that outlines how to respond to changes in BP, including when and how urgently to seek medical attention.

Transient BP elevation can occur when patients are anxious, in pain, in a stressful environment (eg an emergency department) or if they have a full bladder or urinary retention. Assess and treat for causes of transient BP elevation before starting BP-lowering therapy. It may be prudent to allow a period of observation with repeated measurement to see if BP settles without intervention. Reassure the patient and provide analgesia as first-line therapy if severely elevated BP is secondary to pain.

Note: Analgesia is first-line therapy in patients with severely elevated BP secondary to pain.

If a patient is already taking BP-lowering therapy, the appropriate drug choice can be affected by drug interactions, adherence to drug therapy and the potential for cumulative effects of multiple drugs.

Always consider underlying conditions and patient factors that may increase the risk of complications of severely elevated BP or change the approach to management (ie the choice of drug or the urgency of treatment)—see Factors to consider in the management of severely elevated blood pressure.

Table 1. Factors to consider in the management of severely elevated blood pressure
Factors increasing the risk of complications of severely elevated blood pressure
extreme blood pressure elevation (eg higher than 280 mmHg systolic) coagulopathy anticoagulant or antiplatelet therapy recent or imminent thrombolytic therapy previous or current left ventricular failure kidney impairment aneurysm (particularly aortic or intracranial) aortic dissection recent vascular or surgical procedure that required strict periprocedural control of blood pressure pregnancy
Factors affecting choice or urgency of treatment for severely elevated blood pressure
acute pulmonary oedema adrenergic crisis aortic dissection stroke pregnancy baroreflex failure and autonomic dysreflexia current or past drug therapy poor patient cognition or social isolation