Category: Critical Care Nursing Enalapril is an intravenously administered ACE inhibitor. This medication reduces renin-dependent vasopressor activity, blocks the conversion of angiotensin I to angiotensin II and blocks the degradation of bradykinin.
Category: Critical Care Nursing Labetalol has minimal effect on cerebral circulation and is thus not associated with an increase in ICP in the normal brain. The drug has minimal placental transfer and has been used effectively in pregnancy-associated hypertension.
Category: Critical Care Nursing In contrast to traditional beta-blockers, labetalol is associated with the preservation of cardiac output. The hypotensive effect of labetalol has an onset of 2-5 minutes, peak effect at 5-15 minutes and duration of 2-6 hours.
Category: Critical Care Nursing Labetalol acts as an alpha- and nonselective beta-adrenergic blocker. The blood pressure-lowering effect is produced through a reduction in systemic vascular resistance without a compensatory increase in heart rate.
Category: Critical Care Nursing Esmolol reduces blood pressure, heart rate and cardiac output and must be avoided in patients with bradycardia or impaired left ventricular function. It is rapidly cleared by red blood cell esterases and is independent of renal or hepatic function.
Category: Critical Care Nursing Esmolol is a short-acting, cardioselective beta-blocker with a rapid onset and short duration of action (10-20 minutes) that is only administered by continuous infusion. The short half-life requires bolus administration with each infusion titration.
Category: Critical Care Nursing Dihydropyridines calcium channel blockers (e.g., Nicardipine, Clevidipine) are selective to vascular smooth muscle over the myocardium. Thus, they have little effect on heart rate and no effect on myocardial contractility.
Category: Critical Care Nursing Nitroglycerin is a coronary vascular dilator and a systemic venodilator that reduces myocardial preload. Nitroglycerin demonstrates arterial smooth muscle effects only at higher-dose infusions and headache is the most common adverse effect.
Category: Critical Care Nursing Sodium nitroprusside is a arterial and venous vasodilator that reduces preload and afterload. It was once the gold standard for the treatment of hypertensive emergency because of its short duration of action, allowing careful titration.
Category: Critical Care Nursing Hypertension can occur in pregnant women or women in the postpartum period. Acute severe hypertension in the second half of gestation may occur in preeclampsia, gestational hypertension or HELLP syndrome.
Category: Critical Care Nursing The withdrawal of certain medications can be associated with a hypertensive crisis. Rapid withdrawal of clonidine has been associated with a hyperadrenergic state characterized by hypertension, diaphoresis, headache and anxiety.
Category: Critical Care Nursing The preferred agents for the treatment of hypertension resulting from pheochromocytoma are nitroprusside and phentolamine, a potent alpha-adrenergic antagonist. If necessary, phentolamine can be combined with a beta-blocker.
Category: Critical Care Nursing Pheochromocytoma results in the production of circulating catecholamines, which causes hypertension, diaphoresis, tachycardia and paresthesias of the hands and feet. The classic triad includes headaches, palpitations and diaphoresis.
Category: Critical Care Nursing Scleroderma renal crisis is characterized by acute renal failure associated with the abrupt onset of moderate to severe hypertension, elevated plasma renin activity and a normal to minimally abnormal urine sediment.
Category: Critical Care Nursing The kidney is both a source of mediators that promote hypertension (angiotensin II) and a target of high systemic arterial pressure. Chronic hypertension is second to diabetes mellitus as a primary cause of renal insufficiency.
