Randomized trial comparing ferric carboxymaltose vs oral ferrous glycine sulphate for postoperative anaemia after total knee arthroplasty

Background. Despite preoperative anaemia treatment, a risk of postoperative anaemia remains. This randomized, controlled study evaluated the efficacy of i.v. ferric carboxymaltose (FCM) as postoperative anaemia treatment after total knee arthropiasty (TKA). Methods. TKA patients with postoperative anaemia [haemoglobin (Hb) 8.5-12.0 g dl(-1)] without prior transfusions were randomly assigned to FCM [700-1000 mg iron (according to calculate iron deficit on postoperative day 2)] or ferrous glycine sulphate (FS; 100 mg iron daily from day 7 onwards) and followed for Hb, iron status, quality-of-life (EQ-5D), and performance (6 min walk test) until day 30. Results. Of 161 preoperatively non-anaemic patients, 122 (75.8%) developed anaemia after operation (within 24 h) and were enrolled in this study (60 FCM, 62 FS). Hb substantially decreased until day 4 in both groups, and partly recovered by day 30. FCM-treated patients achieved Hb >= 12.0 g dl(-1) more frequently (42.3% vs 23.5%; P=0.04) and showed a trend towards higher Hb increase from day 4 to day 30 [+1.7 (1.2) vs +1.3 (1.0); P=0.075] compared with FS-treated patients. Patients with postoperative Hb <10 g dl(-1) experienced better Hb increase with FCM [+2.4 (0.3) g dl(-1)] than FS [+1.1 (0.4) g dl(-1); P=0.018]. Patients being iron-deficient at enrolment (56.7%) had a higher Hb increase with FCM [+1.9 (0.3) g dl(-1)] than FS [+1.2 (0.2) g dl(-1); P=0.03]. Total EQ-5D and performance outcomes were comparable between the groups, but FCM was associated with better scores for 'usual activities'. No i.v. iron-related adverse events were reported. Conclusions. Preoperatively non-anaemic TKA patients are at high risk of postoperative anaemia. Postoperative i.v. FCM provided significant benefit over oral FS, particularly in patients with preoperative iron deficiency, severe postoperative anaemia, or both.