Hypertensive Encephalopathy :: Treatment & Management :: When therapy is initiated, it is important to consider the baseline blood pressure in order to avoid excessive blood pressure reduction and prevent cerebral ischemia. It is usually safe to reduce MAP by 25% and to lower the diastolic blood pressure to 100-110 mm Hg. Acute monitoring in an intensive care unit (ICU) with arterial blood pressure monitoring is required for adequate titration of pharmacologic agents and monitoring of end-organ function. Deterioration of clinical status despite therapy warrants immediate and further investigation into other possible etiologies or reevaluation of therapy for worsening hypertensive encephalopathy. Pharmacologic agents selected for use in hypertensive encephalopathy should have few or no adverse effects on the central nervous system (CNS). Avoid agents such as clonidine, reserpine, and methyldopa. Although the clinical impact of diazoxide has not been determined, this agent is avoided because of the impact of decreased CBF. An increasing number of authorities are considering labetalol, nicardipine, and esmolol as preferred initial agents. Nicardipine is a second-generation dihydropyridine-derivative calcium channel blocker, which has high vascular selectivity and strong cerebral and coronary vasodilatory activity. It has been shown to increase stroke volume and coronary blood flow.[9] Labetalol provides a steady consistent drop in blood pressure without compromising CBF. It is frequently used as initial therapy. Because of its nonselective beta-blocking properties, labetalol should be avoided in severe reactive airway disease and cardiogenic shock. Nitroglycerin has been used to provide a rapid reduction in elevated blood pressure complicating myocardial ischemia. The reduction in blood pressure may be severe and can cause further complications due to venodilatory effects in volume-contracted individuals. Nitroprusside sodium and hydralazine pose a theoretical risk of intracranial shunting of blood. Accordingly, these agents should be avoided in patients suspected of having increased intracranial pressure (ICP), because the potential intracerebral shunting of blood can increase the ICP. Hydralazine has a limited role in this setting, owing to reflex tachycardia, and it should not be used in patients with suspected coronary artery disease (CAD). Diuretics should also not be used in these patients unless there is clear evidence of volume overload. This is due to pressure natriuresis that occurs and leaves these patients volume depleted. Volume repletion by itself can sometimes lower the blood pressure
Posted on: Sat, 19 Jul 2014 12:01:09 +0000
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