From the Guidelines
Management of a hypertensive emergency requires immediate blood pressure reduction with intravenous medications in an intensive care setting, with the goal of lowering blood pressure by no more than 25% within the first hour, then to 160/100-110 mmHg within the next 2-6 hours, and gradually normalize over 24-48 hours, as recommended by the most recent guidelines 1. The choice of initial medication depends on the specific clinical presentation and comorbidities of the patient.
- For patients with acute aortic dissection, esmolol and nitroprusside or nitroglycerine are preferred, with a goal of lowering systolic blood pressure to <120 mmHg and heart rate to <60 bpm 1.
- For patients with acute coronary events, nitroglycerine is the first-line treatment, with a goal of lowering systolic blood pressure to <140 mmHg 1.
- For patients with acute cardiogenic pulmonary edema, nitroprusside or nitroglycerine (with loop diuretic) are preferred, with a goal of lowering systolic blood pressure to <140 mmHg 1.
- For patients with eclampsia and severe pre-eclampsia/HELLP, labetalol or nicardipine and magnesium sulphate are recommended, with a goal of lowering systolic blood pressure to <160 mmHg and diastolic blood pressure to <105 mmHg 1. It is essential to continuously monitor the patient's cardiac and blood pressure status during treatment, as rapid blood pressure reduction is necessary to prevent further end-organ damage, but overly aggressive treatment can lead to cerebral hypoperfusion 1. After stabilization, transition to oral antihypertensives should be initiated with close follow-up to ensure long-term blood pressure control. The administration of ACE-inhibitors may be considered in some cases, but should be started at a very low dose to prevent sudden decreases in BP, and intravenous saline infusion can be used to correct precipitous BP falls if necessary 1.
From the FDA Drug Label
For a gradual reduction in blood pressure, initiate therapy at a rate of 5 mg/hr. If desired blood pressure reduction is not achieved at this dose, increase the infusion rate by 2.5 mg/hr every 15 minutes up to a maximum of 15 mg/hr, until desired blood pressure reduction is achieved. For more rapid blood pressure reduction, titrate every 5 minutes. The estimated infusion rate necessary to achieve half of this maximal effect was approximately 10 mg/hour
Management of Hypertensive Emergency:
- The recommended initial infusion rate for nicardipine (IV) is 5 mg/hr with gradual increases by 2.5 mg/hr every 15 minutes as needed, up to a maximum of 15 mg/hr 2.
- For clevidipine (IV), the estimated infusion rate to achieve half of the maximal effect is approximately 10 mg/hour 3.
- Key Considerations:
- Monitor blood pressure and heart rate closely during infusion
- Adjust infusion rate as needed to maintain desired response
- Be cautious of potential hypotension or tachycardia and adjust infusion rate accordingly
From the Research
Definition and Classification of Hypertensive Emergency
- Hypertensive emergency is a life-threatening condition characterized by acute target organ damage, requiring immediate reduction of blood pressure 4.
- It can present with neurological, renal, cardiovascular, microangiopathic hemolytic anemia, and obstetric complications 4.
- Hypertensive emergencies are associated with significant morbidity in the form of end-organ damage, and rapid controlled reduction of blood pressure may be necessary to prevent or minimize end-organ damage 5.
Management of Hypertensive Emergency
- The recommended management for hypertensive emergency involves the immediate reduction of blood pressure with intravenous drugs, such as sodium nitroprusside, in an intensive care unit 4.
- Blood pressure should be reduced by about 10% during the first hour and another 15% gradually over the next 2 to 3 hours to prevent cerebral hypoperfusion 4.
- Intravenous antihypertensive agents, such as nicardipine, nitroprusside, fenoldopam, nitroglycerin, enalaprilat, hydralazine, labetalol, esmolol, and phentolamine, are recommended for use in hypertensive emergency 5.
- The selection of a specific agent should be based on the agent's pharmacology and patient-specific factors, such as comorbidity and the presence of end-organ damage 5.
- Newer agents, such as clevidipine, have been shown to be effective and safer alternatives to traditional agents 6, 7.
Specific Considerations
- In patients with aortic dissection, the target is systolic blood pressure <120 mm Hg after 20 minutes 4.
- In patients with hypertensive emergency and pregnancy, oral nifedipine is now considered an alternative first-line therapy, along with intravenous hydralazine and labetalol 7.
- In patients with acute ischemic stroke, clevidipine is now endorsed by guidelines as a first-line treatment option for blood pressure reduction 7.
- In patients with hypertensive heart failure, clevidipine and enalaprilat can be considered for use, although data supporting their use remains limited 7.