Dialysate temperature of 36 °C: association with clinical outcomes

Dialysate cooling, either individualized based upon patient body temperature, or to a standardized temperature below 37 °C, has been proposed to minimize hemodynamic insults and improve outcomes among hemodialysis patients. However, low dialysate temperatures (35-35.5 °C) are associated with patient discomfort, and individualized dialysate cooling is difficult to operationalize. Here, we tested whether a standardized dialysate temperature of 36 °C (dT36) was associated with improved clinical outcomes compared to the default temperature of 37 °C (dT37). Because patients with known hemodynamic instability may be selectively prescribed dT36, we minimized selection bias by considering only incident adult in-center hemodialysis patients who, between Jan 2011 and Dec 2013 received their first-ever hemodialysis treatment at a large dialysis organization. Exposure status was based on the treatment order for this first-ever treatment. 313 dT36 patients were identified and propensity-score matched (1:5) to 1565 dT37 controls. Death, hospitalization, and missed hemodialysis treatments were considered from the date of first-ever hemodialysis treatment until the earliest of death, loss to follow-up, crossover (month in which prescribed dialysate temperature was consistent with patient's exposure group for <80% of treatments), or study end (June 2015). During follow-up, rates of death, hospitalization and missed hemodialysis treatments did not differ between the two groups. This study therefor showed no benefit of dT36 vs. dT37 with respect to these clinical outcomes. Our results do not favor conversion to a default dialysate temperature of 36 °C. Individualized dialysate cooling may provide a more reliable approach to achieve the hemodynamic benefits associated with reduced dialysate temperature.