Pharmacological management of perioperative anaemia: our experience with intravenous iron in orthopaedic surgery

Introduction Preoperative anaemia may be present in up to one-half of surgical patients, depending on the underlying pathology for which they require surgery [1]. Iron deficiency (ID) and chronic inflammation, with or without ID, are the most common causes of preoperative anaemia, although deficiencies of iron, folic acid and/or vitamin B12 without anaemia are also frequent, especially among the elder population [2]. In this regard, in a recent series of 345 patients undergoing major elective orthopaedic surgery the prevalence of preoperative anaemia was 18%, because of haematinic deficiency (30%), chronic inflammation with or without ID (40%), and mixed or unknown cause (30%) [Table 1]. Interestingly, ID was present in 18% of non-anaemic patients, vitamin B12 deficiency in 21%, and folate deficiency in 7% (Table 1). These deficiencies might blunt the response to erythropoiesis-stimulating agents or delay the recovery from postoperative anaemia. In addition, 30% of patients in this series had an Hb level < 13 g/dl [3], and it is well known that a low preoperative haemoglobin level is one of the major predictive factors for perioperative blood transfusion in orthopaedic surgery with moderate to high perioperative blood loss [4,5]. A European study including almost 4000 patients showed an inverse relationship between preoperative Hb values and the probability of receiving allogeneic blood transfusion (ABT) (e.g. 10–18% for Hb 150 g/l, 20–30% for Hb 130 g/l, 50–60% for Hb 100 g/l; 70–75% for Hb 80 g/l) [3]. Similarly, 30–70% of patients undergoing hip fracture repair received ABT perioperatively [6,7], and the logistic regression analysis identified preoperative Hb value as an independent predictor of the need for ABT [7].