Relative Plasma Volume Monitoring and Blood Pressure Control

Abstract

Establishing dry weight in hemodialysis patients is an inexact science.1 Monitoring changes in blood pressure with volume removal is crude but can be effective in establishing dry weight. Unfortunately, probing for dry weight (eg, reduction of volume on dialysis sufficient to reduce blood pressure to <140/90 mm Hg) can lead to intradialytic hypotension, and this is more common in patients with large intradialytic weight gain. Often clinicians use medication-directed blood pressure control strategies in the hemodialysis patient.2 This paradoxically may interfere with the opportunity to achieve dry weight, because if the patient is on increased amounts of antihypertensive medication, more sizeable reductions in blood pressure with ultrafiltration may occur during dialysis.3 This would limit the opportunity for volume removal. As a consequence, the patient would then be chronically volume overloaded. If antihypertensive medication escalation results from inadequate achievement of goal blood pressure during dialysis, a vicious cycle would ensue. The net result is more risk of adverse events from medications and increased ventricular volume and pressure. Recurrent ventricular volume overload may be one of the most important factors leading to heart failure and increased risk of arrhythmia. Thus, …