Kaplan NM, Clinical Hypertension, Fifth Edition, Williams and Wilkins, Baltimore, 1990. The Treatment of Mild Hypertension Research Group, The treatment of mild hypertension study. The presenting picture is consistent with hypertensive encephalopathy, a hypertensive emergency, and the only acceptable treatment is immediate lowering of blood pressure. The differential diagnosis includes stroke and other causes of encephalopathy, which in general are neither helped nor harmed by lowering blood pressure. Use of a short-acting potent vasodilator such as nitroprusside is the preferred treatment, as it is rapidly effective in lowering blood pressure, an effect that can be rapidly reversed if neurological deterioration ensues.
Sublingual nifedipine can cause uncontrolled pressure reductions that compromise organ perfusion.
Temporizing by calling consultants or ordering diagnostic studies as first maneuvers delays effective intervention and can be fatal. Kaplan NM, Clinical Hypertension, Fifth Edition, Williams and Wilkins, Baltimore, 1990. Normal ranges for plasma renin activity are established in untreated subjects. Diuretics, ACE inhibitors and direct-acting vasodilators all raise circulating levels of renin, and the degree of elevation, while variable from patient to patient, can clearly result in values that exceed the normal range. Exogenous estrogens can also contribute to elevated plasma renin activity.