A Pilot Study Evaluating the Effect of Cooler Dialysate Temperature on Hemodynamic Stability During Prolonged Intermittent Renal Replacement Therapy in Acute Kidney Injury

Objectives: Acute kidney injury requiring renal replacement therapy is associated with high morbidity and mortality. Complications of renal replacement therapy include hemodynamic instability with ensuing shortened treatments, inadequate ultrafiltration, and delay in renal recovery. Studies have shown that lowering dialysate temperature in patients with end-stage renal disease is associated with a decrease in the frequency of intradialytic hypotension. However, data regarding mitigation of hypotension by lowering dialysate temperature in patients with acute kidney injury are scarce. We conducted a prospective, randomized, cross-over pilot study to evaluate the effect of lower dialysate temperature on hemodynamic status of critically ill patients with acute kidney injury during prolonged intermittent renal replacement therapy. Design: Single-center prospective, randomized, cross-over study. Setting: ICUs and a step down unit in a tertiary referral center. Patients: Acute kidney injury patients undergoing prolonged intermittent renal replacement therapy. Interventions: Participants were randomized to start prolonged intermittent renal replacement therapy with dialysate temperature of 35°C or dialysate temperature of 37°C. Measurements and Main Results: The primary endpoint was the number of hypotensive events, as defined by any of the following: decrease in systolic blood pressure greater than or equal to 20mm Hg, decrease in mean arterial pressure greater than or equal to 10mm Hg, decrease in ultrafiltration, or increase in vasopressor requirements. The number of events was analyzed by Poisson regression and other outcomes with repeated-measures analysis of variance. Twenty-one patients underwent a total of 78 prolonged intermittent renal replacement therapy sessions, 39 in each arm. The number of hypotensive events was twice as high during treatments with dialysate temperature of 37°C, compared with treatments with the cooler dialysate (1.49±1.12 vs 0.72±0.69; incidence rate ratio, 2.06; p ≤ 0.0001). Treatment sessions with cooler dialysate were more likely to reach prescribed ultrafiltration targets. Conclusions: Patients with acute kidney injury undergoing prolonged intermittent renal replacement therapy with cooler dialysate experienced significantly less hypotension during treatment. Prevention of hemodynamic instability during renal replacement therapy helped to achieve ultrafiltration goals and may help to prevent volume overload in critically ill patients.