From the Guidelines
A hypertensive crisis is a severe elevation in blood pressure that can be further classified into two categories: hypertensive urgency and hypertensive emergency, with the key difference being the presence of acute target organ damage in hypertensive emergency. The distinction between hypertensive crisis and emergency is crucial, as it guides the management approach. According to the most recent guidelines 1, a hypertensive emergency is defined as a blood pressure of ≥180/110 mmHg associated with acute hypertension-mediated organ damage (HMOD), often in the presence of symptoms.
Key Differences
- Hypertensive emergency involves evidence of acute target organ damage, such as cardiac, vascular, and renal alterations, whereas hypertensive urgency does not.
- Hypertensive emergencies require immediate and careful intervention to reduce blood pressure, often with intravenous therapy, whereas hypertensive urgencies can be managed with oral medications in an outpatient setting.
- The goal in hypertensive emergency is to reduce mean arterial pressure by no more than 25% within the first hour, then to 160/100-110 mmHg within the next 2-6 hours, to prevent or limit further target organ damage.
Management Approach
- In a hypertensive emergency, immediate blood pressure reduction is necessary using intravenous medications like labetalol, nicardipine, or nitroprusside in an intensive care setting.
- In contrast, hypertensive urgency can be managed with oral medications like captopril, labetalol, or amlodipine over 24-48 hours in an outpatient setting with close follow-up.
- The choice of treatment, target blood pressure, and timeframe for blood pressure reduction depend on the type of target organ damage and the clinical condition involved, as outlined in the guidelines 1 and 1.
Clinical Implications
- Hypertensive emergencies can cause life-threatening complications, including stroke, myocardial infarction, acute heart failure, aortic dissection, or encephalopathy.
- Inappropriate rapid reduction of blood pressure in hypertensive urgency can lead to organ hypoperfusion and ischemia, highlighting the importance of distinguishing between hypertensive urgency and emergency.
- The guidelines emphasize the need for careful and immediate intervention in hypertensive emergencies to prevent or limit further target organ damage, as outlined in the European Heart Journal 1 and 1.
From the Research
Definition of Hypertensive Crisis and Emergency
- A hypertensive crisis is defined as a systolic blood pressure > 180 mm Hg or a diastolic blood pressure > 120 mm Hg 2, 3, 4.
- Hypertensive crises are categorized as either hypertensive emergencies or urgencies depending on the degree of blood pressure elevation and presence of end-organ damage 2, 3, 4, 5.
Difference between Hypertensive Emergency and Urgency
- Hypertensive emergency: characterized by acute end-organ damage, requiring immediate reduction in blood pressure with a titratable short-acting intravenous antihypertensive agent 2, 3, 4, 5.
- Hypertensive urgency: severe hypertension with no or minimal end-organ damage, usually treated with oral antihypertensive agents 2, 3, 4, 5.
Treatment Approaches
- Patients with hypertensive emergencies are best treated in an intensive care unit with titratable intravenous hypotensive agents 2, 3, 4.
- Rapid-acting intravenous antihypertensive agents available include labetalol, esmolol, fenoldopam, nicardipine, and clevidipine 2, 3, 4, 5.
- Sodium nitroprusside, nifedipine, nitroglycerin, and hydralazine should not be considered first-line therapies due to significant toxicities and/or side effects 2, 3, 4, 5, 6.