Eclampsia and Pre-eclampsia
These conditions are characterized by gestational BP elevation and proteinuria. Magnesium sulfate IV reduces the frequency of eclampsia-induced HTN and pre-eclampsia. Treatment with antihypertensive agents should begin when the systolic BP is > 160 mmHg and/or the diastolic BP is > 110 mmHg. ACEIs and angiotensin II antagonists are contraindicated due to the risk of fetal and neonatal morbidity. Labetolol, nicardipine, and hydralazine may be used. Note: Hydralazine is a potent vasodilator and is effective in eclampsia/pre-eclampsia, but can cause rebound tachycardia and HTN if it is stopped abruptly.
Cocaine-induced Hypertensive Emergency
Cocaine is a sympathomimetic drug that stimulates both α-1 and β-1 and 2 receptors. Cocaine intoxication leads to vasoconstriction of peripheral and epicardial arteries. The use of labetolol and other β-blockers is specifically contraindicated in cocaine toxicity. Labetolol is potentially deadly, as it has both α- and β-blocking activity and, when given in cocaine toxicity, results in complete cardiac β-blockade and unopposed vasoconstriction of the epicardial coronary arteries. The revised AHA recommendations for cocaine-related HTN are nitroglycerin, Verapamil, and benzodiazepines (lorazepam) as first-line treatments. Phentolamine is a second-line agent.
Ninety percent of aortic dissections are associated with severe HTN. Aortic dissection is classified as Type A when the intimal tear begins in the ascending aorta and progresses throughout the aorta, often extending as far as the arteries in the leg. Type A requires emergent surgery. In Type B aortic dissection, the intimal tear is located just past the left subclavian artery (the blood vessel beneath the collarbone that supplies the left arm), but does not expand past the arch of the aorta. Type B is managed medically with gradual, monitored BP reduction. A combination of β-blockade (Esmolol) and a potent antihypertensive agent, such as nitroprusside or nicardipine is indicated.
The elderly are a high-risk group for hypertensive crises and need to be managed carefully due to physiological variations due to aging. Reduced drug doses and longer dosing intervals should be considered. Despite the emphasis on aggressive treatment of stage I and II hypertension with at least 2 drugs, several studies indicate that isolated systolic HTN can be controlled in the elderly with diuretics alone because many suffer from high-sodium "V" type (volume-dependent) HTN.
Journal for Nurse Practitioners. 2010;6(5):338-346. © 2010 Elsevier Science, Inc.
Cite this: Hypertensive Crisis in an Era of Escalating Health Care Changes - Medscape - May 01, 2010.