... treatment of hypertensive emergencies, with a detailed look at medications.
Defined by hypertension with end-organ dysfunction. Hypertensive urgency, or severely elevated hypertension without symptoms, does not require treatment in the ED.
A rapid, marked and persistent rise in blood pressure (BP) levels above 180/120 mmHg is a clinical condition currently defined as hypertensive emergency or urgency in the presence or absence of acute signs of hypertension-mediated organ damage, respectively.
The formula for calculating mean arterial pressure (MAP) is systolic + diastolic x’s 2 divided by 3 or (SBP+2DBP)/3.
We tend to focus on the systolic blood pressure (“she had a systolic of 250!!”). However, the risk of hypertensive emergency seems overall be more closely related to the diastolic pressure than the systolic pressure. MAP is probably the single parameter most closely related to the risk of hypertensive emergency.
For the vast majority of patients with elevated BP in the ED who do not have new or worsening end-organ injury from elevated BP, immediate BP reduction within the ED is not recommended or safe.
Goal BP reduction of MAP 20% in the first hour.
Gradual normalization over the next 24-48h.
Unless unclipped aneurysmal bleed or aortic dissection.
The recommended first-line therapy for patients with severe hypertensive acute heart failure (H-AHF) remains intravenous (IV) vasodilators (via bolus) proven safe and effective (e.g., nitroglycerin), with a treatment target of ≤25% reduction in systolic blood pressure (SBP)...
In hypertensive emergencies, BP should almost never be rapidly
• Goal of 10-20% reduction of MAP in first hour, and then 5-15%
further in next 23 hours. – Usually results in acute target of <180/<120 in first hour, then <160/<110
in next 23 hours.
• Exceptions: – Acute aortic dissection (SBP < 120 in 20 minutes) – Acute ischemic stroke (tPA candidate < 185/110)
Calcium channel blockers (CCBs) remain the workhorses for management of hypertensive emergency due to their ideal pharmacokinetics, minimal adverse effects, and (relatively) predictable hemodynamic response.
Per the JNC 7, a hypertensive emergency is a hypertensive crisis in which there is evidence of acute target-organ damage (e.g., encephalopathy, myocardial infarction, unstable angina, pulmonary edema, stroke, life-threatening arterial bleeding, or aortic dissection). Such cases warrant parenteral drug therapy and hospitalization, often to an intensive care setting.
Having end-organ damage is the hypertensive emergency. Having high blood pressure without any signs of end-organ damage is the hypertensive urgency.