Intensive dialysis and blood pressure control: a review.

The prevalence of hypertension in hemodialysis (HD) patients has increased over the years. In the early days of maintenance HD blood pressure (BP) control was achieved in most patients. As sessions were shortened, the prevalence of hypertension increased. Yet, in principle, dialysis is able to control hypertension. Today, in programs using long HD, most patients are normotensive without antihypertensive medication. The same is true for patients on daily dialysis, but not for those on short thrice-weekly HD. In all studies reporting BP normalization, dry weight is regularly achieved. Why the poor control of hypertension now? At first sight the shortened session duration is the culprit. This is suggested by several epidemiologic observations and strongly supported by a prospective experience of changing the HD schedule (short to long HD or conversely) in the same group of patients. Recent studies, however, using strict volume control show that BP normalization can be obtained in conventional 3 x 4 hr/week dialysis with relatively low delivered Kt/V(urea). Therefore, prolonging the dialysis time and/or increasing the dialysis dose are not required to achieve BP control. Intensive dialysis most probably normalizes BP by getting the extracellular volume and the amount of sodium in the body back to normal. It acts in conjunction with a moderate dietary sodium restriction and the use of reasonably low dialysate sodium. With this approach improved BP control can be achieved in the vast majority of HD patients.