HYPERTENSIVE EMERGENCIES
The initial goal for blood pressure reduction is not to obtain a normal blood pressure, but rather to achieve a progressive but controlled reduction in blood pressure to minimize the risk of hypoperfusion in cerebral, coronary, and renal vascular beds.5 It is recommended that the initial reduction in mean arterial pressure (MAP) not be more than 20%–25% below the pretreatment blood pressure, or that MAP be reduced within the first 30–60 minutes to 110–115 mm Hg.6 If this level of blood pressure is well tolerated and the patient is clinically stable, further gradual reductions toward a normal blood pressure can be effected over the next 12–24 hours. Excessively rapid reduction in blood pressure has been associated with acute deterioration in renal function, ischemic, cardiac, or cerebral events, and occasional retinal artery occlusion and acute blindness.