This patient with preeclampsia with severe features has developed new-onset severe-range hypertension, severe headache, and emesis.  Hypertension is a leading cause of maternal and fetal morbidity and mortality.  Severe-range blood pressure (ie, systolic ≥160 mm Hg or diastolic ≥110 mm Hg) increases the risk of maternal stroke (hemorrhagic and ischemic), pulmonary edema, and myocardial ischemia; fetal risks include abruptio placentae and intrauterine demise.  Therefore, acute antihypertensive therapy is required to stabilize the patient, reduce the risk of maternal stroke, and improve fetal outcome.

First-line medications for acute antihypertensive therapy include:

• Intravenous labetalol: a beta blocker with alpha-blocking activity.  Labetalol is fast-acting, effective, and safe for use during pregnancy; however, in patients with bradycardia (ie, <60/min), beta blockade with labetalol can further decrease the heart rate, resulting in dizziness or lightheadedness (Choice C).

• Intravenous hydralazine: a direct arterial vasodilator.  Hydralazine can cause tachycardia due to sympathetic nervous system stimulation.

• Oral nifedipine: a calcium channel blocker.  Although oral nifedipine can rapidly lower blood pressure, this patient may not be able to tolerate oral medications due to nausea/vomiting.

Because the patient is both bradycardic and at risk for emesis, intravenous hydralazine is the most appropriate medication.  In addition, the patient requires intravenous magnesium sulfate to decrease the risk of eclamptic seizure.

(Choice A)  Loop diuretics (eg, furosemide) can lower blood pressure but also deplete intravascular volume and decrease fetoplacental perfusion, resulting in fetal hypoxia.  Therefore, they are typically avoided during pregnancy with some exceptions (eg, management of pulmonary edema due to preeclampsia with severe features).

(Choice D)  Methyldopa, a centrally acting adrenoreceptor antagonist, is safe during pregnancy but more appropriate for treating chronic hypertension due to slow onset and relatively low potency.

(Choice E)  Sodium nitroprusside is typically a last resort for antihypertensive therapy and used with great caution because cyanide is a metabolic byproduct.

Educational objective:
New-onset severe-range hypertension (ie, systolic ≥160 mm Hg or diastolic ≥110 mm Hg) during pregnancy can occur in patients with preeclampsia with severe features.  Severe hypertension increases maternal risk of stroke, pulmonary edema, and myocardial ischemia; fetal risks include abruptio placentae and intrauterine demise.  Acute antihypertensive therapy with hydralazine, labetalol, or nifedipine is required.