Efficacy of Intraoperative Administration of Iron Isomaltoside for Preventing Postoperative Anaemia after Total Knee Arthroplasty: A Randomised Controlled Trial

Abstract

Background: Postoperative anaemia is common after total knee arthroplasty (TKA). Emerging evidence shows the beneficial effects of perioperative iron supplementation in patients at risk of postoperative anaemia. In this study, we aimed to evaluate the efficacy of intraoperative administration of iron isomaltoside for preventing post-TKA anaemia. Methods: This prospective randomised, controlled, double-blinded, parallel-group study was conducted at a tertiary care teaching hospital in Seoul, Korea. Patients undergoing unilateral TKA were randomly assigned to receive intravenous iron isomaltoside or placebo intraoperatively, based on a computer-generated randomisation list. The administered dose of iron isomaltoside was determined based on preoperative haemoglobin level and body weight of each patient according to the manufacturer’s recommendation. The primary outcome measure was the incidence of postoperative anaemia at 30 days after TKA, analysed by intention-to-treat. Findings: Between March 29, 2018, and April 16, 2019, 164 patients were screened for eligibility. In total, 89 patients were included in the final analysis (44 in the treatment group; 45 in the control group). The incidence of postoperative anaemia at 30 days after TKA was significantly lower in the treatment group than that in the control group (15/44 [34·1%]) vs 28/45 [62·2%]; relative risk, 0·55 [95% CI 0·34–0·88], P=0·008). Haemoglobin level, serum ferritin concentrations, and iron saturation were also significantly higher in the treatment group at 30 days after TKA. However, there were no significant differences in both quality of life assessments. Interpretation: Intraoperative administration of iron isomaltoside effectively prevents post-TKA anaemia, and thus it can be included in patient blood management protocols for reducing postoperative anaemia in patients undergoing TKA. Trial Registration: This study is registered with ClinicalTrials.gov (number NCT03470649) and has completed recruitment. Funding Statement: This study was funded by Phambio Korea Inc., Seoul, Korea. Declaration of Interests: The authors declare that they have no conflicts of interest. Ethics Approval Statement: This prospective randomised, controlled, double-blinded, parallel-group study was approved by the Institutional Review Board of Soul National University Hospital, Seoul, Korea (No. H-1709-079-885). The study was conducted in accordance with the Declaration of Helsinki, and written informed consent was obtained from all participants.