Supplementary Material for: Intraoperative continuous renal replacement therapy in non-cardiac, non-liver transplantation surgery: an observational cohort feasibility study.

Introduction: Renal replacement therapy (RRT) is commonly used to manage metabolic disturbances in critically ill patients with acute kidney injury. While intraoperative RRT has been assessed in liver transplantation and cardiac surgery, its use in other surgical contexts remains unexplored. This study aimed to assess the feasibility of intraoperative continuous RRT (IoCRRT) in non-cardiac, non-liver transplant surgeries. Secondary objectives included evaluating safety and describing the patient population.
Methods: This retrospective study included all adult patients who underwent IoCRRT between January 2013 and January 2021 at Hospices Civils de Lyon (Lyon, France). Patients were classified as undergoing emergency or elective surgery. Data on IoCRRT indication, feasibility, safety, renal function at hospital discharge and mortality were analyzed.
Results: IoCRRT was successfully implemented in all 43 patients. Severe acidosis (pH < 7.2) was the main indication for IoCRRT in 27 patients (82%) of the emergency group, while IoCRRT was initiated to prevent metabolic complications and electrolyte imbalances in elective surgeries. Regional citrate anticoagulation was used in 36 (84%) cases. No adverse event was reported. At hospital discharge, no survivor progressed to end-stage renal disease; 4 (29%) patients exhibited a glomerular filtration rate (GFR) of 60–90 mL/min/1.73m², and 10 (71%) an GFR > 90 mL/min/1.73m². Twenty-seven patients (63%) died within 30 days.
Conclusion: IoCRRT seems to be a feasible and safe adjunctive therapy during emergency or elective surgery in patients with severe metabolic disorders. No IoCRRT-related complication was reported. Renal function appeared preserved. Further prospective studies are warranted to confirm these findings.