Modern CRRT systems are associated with lower risk of hypothermia.

One risk of continuous renal replacement therapy (CRRT) is inadvertent hypothermia (IH), which is defined as a non-therapeutic core temperature decrease below normal. In continuous renal replacement therapy, heat loss will always occur from blood pumped through the dialysis circuit to cooler environment, predisposing for hypothermia. Blood flow and effluent flows are the most important parameters causing heat loss. We investigated and compared the novel TherMax warmer to previous generation technologies during CRRT in a multicenter setting. This was a prospective observational multicenter study with historic single-center controls. The study group consisted of 100 patients in eight Swedish ICUs with clinical indication for CRRT, using the PrisMax platform and TherMax warmer. Both patient and set warmer temperatures were recorded hourly for the first 24 h. The presence of treatment hours in hypothermia (< 36.0 Celsius) and the difference between set warmer temperature and measured patient temperature in the multi-center study cohort were compared to a matched single-center historic control cohort treated with the old Prismaflex platform and adjacent Barkey warmer. In the TherMax group 77/100 (77.0%) of patients, and for controls 26/86 (30.2%) of patients were free of hypothermia (Chi square, p < 0.001). The mean number of hours spent in hypothermia was (mean ± SD) 0.66 ± 1.60 and 6.92 ± 7.79 h in the TherMax and control groups, respectively (Chi square p < 0.001). In the study group the patient temperature was higher than the set temperature on the warmer with a difference of Δ0.47 ± 0.80 °C (minor difference), whereas in the control group the set temperature on the warmer was higher than the patient temperature with a difference of Δ4.55 ± 1.00 °C (over-correction). The novel TherMax warmer technology protected against hypothermia and was significantly more accurate than the Barkey warmer.