RESUMO
Patients undergoing total hip or knee replacement frequently receive blood transfusion. Homologous blood transfusion carries appreciable risks and should therefore be reduced to a minimum. We have investigated the use of preoperative oral iron supplements to optimize haemoglobin concentration and iron stores prior to surgery. All patients attending a preadmission clinic 4 weeks prior to primary hip or knee replacement had a haemoglobin measurement. If the haemoglobin concentration (Hb) was less than 12 g dL-1 they were given a four week course of ferrous sulphate. If it was greater than or equal to 12 g dL-1 they were randomized to a control group or given a supplementation course of ferrous sulphate. One hundred patients were seen. Of these 18 (18%) had haemoglobin less than 12 g dL-1 and 16 were treated with iron. The mean Hb was 10.8 g dL-1 and mean cell volume (MCV) 86. These patients increased their Hb by a mean 1.1 g dL-1 prior to admission (P = 0.008). MCV was the best predictor of response (r = -0.63, P < 0.02). This group dropped their haemoglobin by a mean 1.4 g dL-1 in the first post-operative week. In the study groups there was no significant preoperative rise in Hb. However, the control group dropped their Hb by a mean 1.3 g dL-1 in the week following surgery compared with 0.4 g dL-1 in the group which had received iron supplements (P < 0.001). We conclude that at least 18% of patients attending for hip or knee replacement in this region are frankly anaemic and benefit significantly from preoperative iron supplements over 4 weeks. Iron supplementation in patients without obvious anaemia protects against a fall in Hb during the immediate post-operative period, suggesting a widespread underlying depletion of iron stores in this group despite a normal Hb. Preoperative iron supplements may reduce transfusion requirements as part of a co-ordinated strategy in this group of patients.