Efficacy of intra-operative 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 peri-operative iron supplementation in patients at risk of postoperative anaemia.

Objective: To evaluate the efficacy of intra-operative administration of iron isomaltoside for the prevention of postoperative anaemia in patients undergoing TKA.

Design: Randomised, controlled, double-blind, parallel-group study.

Setting: A tertiary care teaching hospital; between 29 March 2018 and 16 April 2019.

Patients: Eighty-nine patients scheduled for unilateral TKA were included.

Intervention: Iron isomaltoside or placebo were administered intravenously over 30 min during surgical wound closure.

Main outcome measures: The primary outcome measure was the incidence of anaemia at 30 days after TKA: anaemia was defined as haemoglobin less than 12 g dl-1 for female and less than 13 g dl-1 for male.

Results: In total, 89 patients were included in the final analysis (44 in the treatment group; 45 in the control group). The administered dose of iron isomaltoside in the treatment group was 1136 ± 225 mg. The incidence of anaemia at 30 days after TKA was significantly lower in the treatment group (34.1%, 15/44) than that in the control group (62.2%, 28/45): relative risk 0.55 (95% confidence interval, 0.34 to 0.88), P = 0.008. Haemoglobin concentration, serum ferritin concentrations, and transferrin saturation were also significantly higher in the treatment group at 30 days after TKA.

Conclusion: The intra-operative administration of iron isomaltoside effectively prevents postoperative anaemia in patients undergoing TKA, and thus it can be included in patient blood management protocols for reducing postoperative anaemia in these population.

Trial registration: ClinicalTrials.gov identifier: NCT03470649.