Iron studies and red cell transfusion in cardiothoracic and orthopaedic surgical patients: a retrospective audit at a tertiary hospital

Abstract

Preoperative diagnosis and treatment of anaemia are important to minimize adverse postoperative outcomes. This audit reviewed red cell transfusion practice, degree of anaemia, iron deficiency anaemia (IDA) and chronic disease or anaemia of inflammation (AI) in cardiothoracic and orthopaedic surgical patients who had available iron studies. A total of 178 consecutive cardiothoracic and orthopaedic surgical patients with available iron studies were retrospectively reviewed. Of patients, 36·5% had preoperative iron studies. However, 63·2% males and 45·3% females with postoperative iron studies presented with anaemia; 38·5% patients with preoperative iron studies had AI; 21·5% IDA; 23·1% normal. For patients with iron studies requested within the first two postoperative intervals (≤ 5 days and 6 ≤ 10 days) 73·8% and 63·6%, respectively, had AI; few had classical IDA or were normal, and 51·5% patients transfused postsurgery had a discharge Hb ≥ 110 g/l. Restricting the discharge Hb to 90 or 100 g/l may have eliminated postsurgical transfusion in 14·8-42·6% patients. Iron studies were more commonly requested postoperatively despite many being anaemic at admission. A higher proportion of patients with postoperative iron studies had AI, and few had classical IDA or normal iron parameters, suggesting a transient inflammatory effect of surgery. This may mask underlying IDA or normal iron parameters and affect treatment. Preadmission assessment, including iron status, should be emphasized allowing diagnosis and correction of presurgical anaemia with treatment modalities other than red cell transfusion. In the postsurgical setting, consideration of a restrictive transfusion regimen sufficient to alleviate a patient's clinical symptoms would ensure that this valuable resource is appropriately used.