The prevalence of iron deficiency anaemia in patients undergoing bariatric surgery

As bariatric surgery rates continue to climb, anaemia will become an increasing concern. We assessed the prevalence of anaemia and length of hospital stay in patients undergoing bariatric surgery. Prospective data (anaemia [haemoglobin <12 g/dL], haematinics and length of hospital stay) was analysed on 400 hundred patients undergoing elective laparoscopic bariatric surgery. Results from a prospective database of 1530 patients undergoing elective general surgery were used as a baseline. Fifty-seven patients (14%) were anaemic pre-operatively, of which 98% were females. Median MCV (fL) and overall median ferritin (μg/L) was lower in anaemic patients (83 vs. 86, p=0.001) and (28 vs. 61, p<0.0001) respectively. In the elective general surgery patients, prevalence of anaemia was similar (14% vs. 16%) but absolute iron deficiency was more common in those undergoing bariatric surgery; microcytosis p<0.0001, ferritin <30 p<0.0001. Mean length of stay (days) was increased in the anaemic compared to in the non-anaemic group (2.7 vs. 1.9) and patients who were anaemic immediately post-operatively, also had an increased length of stay (2.7 vs. 1.9), p<0.05. Absolute iron deficiency was more common in patients undergoing bariatric surgery. In bariatric patients with anaemia there was an overall increased length of hospital stay.