Control of hypertension in the critically ill: a pathophysiological approach.

Severe acute arterial hypertension can be associated with significant morbidity and mortality. After excluding a reversible etiology, choice of therapeutic intervention should be based on evaluation of a number of factors, such as age, comorbidities, and other ongoing therapies. A rational pathophysiological approach should then be applied that integrates the effects of the drug on blood volume, vascular tone, and other determinants of cardiac output. Vasodilators, calcium channel blockers, and beta-blocking agents can all decrease arterial pressure but by totally different modes of action, which may be appropriate or contraindicated in individual patients. There is no preferred agent for all situations, although some drugs may have a more attractive profile than others, with rapid onset action, short half-life, and fewer adverse reactions. In this review, we focus on the main mechanisms underlying severe hypertension in the critically ill and how using a pathophysiological approach can help the intensivist decide on treatment options.