REDUCING SYMPTOMS DURING HEMODIALYSIS BY CONTINUOUSLY MONITORING THE HEMATOCRIT

Previous studies have demonstrated that patients on hemodialysis devel op intradialytic symptoms when the blood volume decreases to a critica l level. Using a continuous monitor (CRIT-LINE; In-line Diagnostics, R iverdale, UT) to determine the instantaneous hematocrit and blood volu me, we observed that certain intradialytic symptoms occurred at a pati ent-specific hematocrit. In the present study, we exploited this hemat ocrit threshold concept to decrease the occurrence of lightheadedness, cramping, and nausea, regardless of blood pressure changes. In the fi rst phase of the study, hematocrit threshold was established in six hy potension-prone patients. Five patients entered into the second phase in which ultrafiltration rates were increased 25% above prescribed val ues at the beginning of the experimental sessions. Subsequently during the experimental sessions, ultrafiltration rates were manipulated to maintain the instantaneous hematocrit value 2 units below the establis hed hematocrit threshold. Sessions without ultrafiltration rate adjust ments based on hematocrit served as controls. There were no difference s between experimental (n = 27) and control (n = 28) sessions with res pect to treatment time (230 minutes v 229 minutes), fluid volume remov ed (3,351 mL v 3,383 mL), and maximum percentage change in systemic bl ood pressure (-26% v -24%). However, there were less symptoms during t he experimental sessions (26% v 57%; P = 0.038). These data suggest th at a twofold reduction in intradialytic symptoms can be achieved using continuous hematocrit monitoring without altering treatment times or volume removed in hypotension-prone patients. (C) 1996 by the National Kidney Foundation, Inc.