Background: Intradialytic hypotension (IH) is a common adverse event. Currently, there are several commonly utilized therapies of IH, but they have not been compared directly in the same group of patients. We performed the present study in order to learn which of these techniques is most effective so that a rational approach to treating IH could then be formulated.
Methods: A single-blinded, crossover study design of five different protocols was undertaken in 10 hemodialysis patients with a prior history of IH. Each patient first underwent one week (three dialyses) of standard dialysis (dialysate sodium 138 mEq/L). Then each patient was subjected to one week each (three dialyses) of the four test protocols, performed in random order in a blinded fashion. The specific protocols were as follows: high sodium dialysate, in which the patient was dialyzed using a dialysate sodium of 144 mEq/L; sodium modeling, during which the dialysate sodium declined from 152 to 140 mEq/L in the last half hour of dialysis; one hour of isolated ultrafiltration followed by three hours of isovolemic dialysis; and cool temperature dialysis in which the dialysate was cooled to 35 degrees C.
Results: Weight loss in each of the five protocols was essentially identical, varying between 2.9 and 3 kg. There were significantly fewer hypotensive episodes per treatment in the sodium modeling, high sodium, and cool temperature protocols as compared with the standard protocol (P < 0.05). Ultrafiltration followed by dialysis was associated with a significantly greater number of hypotensive episodes per treatment than any of the three test protocols (P < 0.05). Similarly, the number of nursing interventions required for IH per treatment was significantly greater in the standard dialysis and in the isolated ultrafiltration protocols compared with sodium modeling and cool temperature protocols (P < 0.05). The number of hypotensive signs and symptoms per treatment was also significantly reduced during the sodium modeling and cool temperature protocols compared with the standard protocol (P < 0.004 and P < 0.02, respectively). Again, the isolated ultrafiltration protocol resulted in significantly more hypotensive symptoms and signs than the three test protocols (P < 0.005). Finally, the nadir mean arterial pressures were significantly lower in the standard and isolated ultrafiltration protocols when compared with the three test protocols (P < 0.05). The upright postdialysis blood pressure was best preserved in the sodium modeling and cool temperature protocols compared with the standard and isolated ultrafiltration protocols (P < 0.05).
Conclusion: This study supports the use of sodium modeling as a first step in combating IH. Also effective were the use of cool-temperature dialysate and a high-sodium dialysate. All three test protocols were well tolerated. As applied in this study, isolated ultrafiltration followed by isovolemic dialysis was notably less effective in reducing IH.