Supplementary Material for: Current status of continuous renal replacement therapy in Japanese intensive care units: a multicenter retrospective observational study

Introduction: Continuous renal replacement therapy (CRRT) is often performed for critically ill patients in intensive care units (ICUs), but its optimal indication and settings have yet to be determined. Thus, we aimed to describe the current status of CRRT in Japan through a multicenter retrospective observational study.
Methods: Adult ICU patients receiving CRRT at 18 tertiary hospitals in Japan (up to 100 patients from each hospital over the past year) were retrospectively enrolled. Patients receiving CRRT for <24 hours or intermittent renal replacement therapy together with CRRT were excluded. The primary outcomes were the temporal changes in the electrolyte levels, acid–base balance, and uremia-related small solute concentrations. The secondary outcomes included potassium (K) and phosphate (P) supplementations during CRRT.
Results: Altogether, 1045 patients were enrolled. The median CRRT duration and dose were 4.4 days and 17.3 mL/kg/hr, respectively. The electrolyte levels, acid–base balance, and uremia-related small solute concentrations returned to normal by day 4 of treatment. A total of 732 (70.0 %) patients received K supplementation, and only a few patients had hypokalemia until day 5. Moreover, 414 (39.6%) patients received P supplementation, and approximately 30%–50% of the patients had hypophosphatemia until day 5.
Conclusion: The electrolyte level abnormalities and acid–base imbalances of the studied patients were improved within 72–96 hours of CRRT. Contrarily, K and P supplementations were common, indicating that the current CRRT solutions need to be modified.