Blood Pressure Management in Hemodialysis Patients: What We Know And What Questions Remain

Abstract

Despite having thousands of blood pressure (BP) readings on individual dialysis patients over the course of a year, our knowledge about the optimal assessment of BP, the mechanisms underlying hypertension and its management remain incomplete. Observational studies reveal that BP is lower at home than when measured in the dialysis unit. However, we do not know if using home vs. in-center measurements to guide treatment decisions improves BP control and/or clinical outcomes. Moreover, a recent US study suggests that typical hemodialysis patients are unlikely to adhere to home monitoring over the long term. Volume excess is one of probably many factors mediating hypertension in this population. A randomized clinical trial of aggressively challenging dry weight in patients without overt signs of fluid overload was shown to reduce BP, but there was an increase in vascular access thrombosis and intradialytic hypotension episodes. Long-term studies have not been done; thus, we do not know whether "squeezing dry weight" as a means to control BP is of more benefit than harm. Daily or prolonged nocturnal dialysis consistently has been shown to lower BP. To what extent this is a result of enhanced solute clearance vs. removal of excess volume is not clear. Use of bioimpedance or relative blood volume monitoring to guide fluid management has been tested in small studies, but more data are needed to determine whether their use impacts clinical outcomes. Well-designed clinical trials to determine whether a specific antihypertensive drug class is of benefit, independent of BP lowering, are lacking. The BP target that optimizes outcomes HD patients is also unknown. Observational studies consistently show poorer survival with predialysis BP <140/90 mmHg, although such studies likely are confounded by low BP due to cardiovascular disease and other comorbidities. In this review, we discuss what is known and the questions that remain regarding the epidemiology, diagnosis, etiology, and management of hypertension in hemodialysis patients.