ENHANCED FLUID REMOVAL GUIDED BY BLOOD-VOLUME MONITORING DURING CHRONIC-HEMODIALYSIS

Fluid overload predisposes chronic hemodialysis patients to cardiovasc ular disease, a significant cause of morbidity and mortality in these patients. We evaluated the efficacy of monitoring changes in blood vol ume during routine hemodialysis to detect fluid overload. Intradialyti c changes in blood volume were monitored by continuously measuring hem atocrit in all 56 patients in a single dialysis unit over 7 weeks. Aft er Week 1, patients were categorized into 2 separate groups depending on their maximum intradialytic decreases in blood volume. In Group 1, 46 of 56 or 82% had greater than a 5% decrease in blood volume while i n Group 2, 10 of 56 or 18% had less than a 5% decrease in blood volume . During Weeks 2-7, dialytic fluid removal was intentionally increased in Group 2 patients by 0.80 +/- 0.62 L (mean +/- SD) or 47 +/- 43%. T his intervention resulted in a larger (p < 0.02) intradialytic decreas e in body weight (2.7 +/- 0.9 kg versus 2.0 +/- 0.8 kg) and a larger ( p < 0.02) intradialytic decrease in blood volume (15 +/- 5% versus 4 /- 1%) than experienced during Week 1 with a low incidence of symptoms . We conclude that there is a significant percentage of chronic hemodi alysis patients who can tolerate additional fluid removal without hypo volemic symptoms even though they are considered to be at dry weight b y routine physical examination and that the identification of these pa tients can be facilitated by intradialytic blood volume monitoring.