Can Chronic Volume Overload Be Recognized and Prevented in Hemodialysis Patients?

Postdialysis Hypertension: Associated Factors, Patient Profiles, and Cardiovascular Mortality

BACKGROUND AND OBJECTIVES

A postdialytic increase in blood pressure (BP) is a recognized but often an overlooked complication. The epidemiology and predisposing factors are still not well defined. We studied a large sample of Italian dialysis patients to assess the prevalence of postdialysis hypertension (PDHYPER), defined as any increase of systolic BP (SBP) >10mm, Hg above the predialysis value, the associated factors and its role in cardiovascular (CV) mortality.

PATIENTS AND METHODS

In this observational study, we assessed dialysis associated changes in BP in 4,292 hemodialysis (HD) patients over 1 month (51,504 sessions). We compared the clinical characteristics of the patients with stable BP values during the HD session with those with PDHYPER. We also assessed the impact of PDHYPER on CV mortality.

RESULTS

A total of 994 (23.1%) patients had PDHYPER. Patients with PDHYPER were more likely to be hypertesive, older, have a shorter dialysis vintage, be male, have lower SBP, lower changes in weight during HD, and receive more antihypertensive medications. These predictive factors were shown to be associated with an interaction between weight loss and dialysis, suggesting a volume-related mechanism in its pathogenesis. PDHYPER was also associated with CV mortality.

CONCLUSIONS

In our study on a large Italian cohort of dialysis patients, the prevalence of PDHYPER was higher than what was previously reported and is a significant risk factor for CV mortality in dialysis patients. The pathogenesis is multifactorial but hypertensive state, antihypertensive medications, and extracellular volume expansion appear to play a major role.

Blood pressure management in hemodialysis: what have we learned?

PURPOSE OF REVIEW

To review recent developments in the field of hypertension in hemodialysis patients.

RECENT FINDINGS

Despite the fact that hypertension is the most common complication of end-stage kidney disease, no evidence-based blood pressure (BP) targets exist for hemodialysis patients. There is growing evidence that outcomes are better predicted by out-of-office BP values, such as home or ambulatory BP monitoring. Intradialytic hypertension is associated with increased risk of death or hospitalization, and is probably mediated by volume overload. BP management should focus on volume control: dry weight 'probing' is well tolerated and effective in lowering BP, as are other strategies that minimize expansion of the extracellular fluid volume, such as avoidance of hypernatric dialysate. We discuss each of these issues in our review.

SUMMARY

Modest advances in the understanding of hypertension have occurred in the past 2 years. Clinical trials that focus on BP targets and treatment choices are essential to guide future practice.