Supplementary Material for: Post-Operative Iron Carboxymaltose May Have an Effect on Haemoglobin Levels in Cardiothoracic Surgical Patients on the ICU - an Observational Pilot Study about Anaemia Treatment with Intravenous Iron

Background: Post-operative anaemia is associated with increased morbidity and mortality. Positive effects of post-operative intravenous iron (IVI) after elective orthopaedic, abdominal and genitourinary surgery have been reported. The current observational trial investigated the prevalence of post-operative anaemia, the effect of IVI on haemoglobin levels, the use of blood transfusions and diagnoses related to infections. Methods: 1,265 patients on five ICUs of Münster University Hospital were screened for post-operative anaemia. On one ICU, patients were screened for iron deficiency and, if indicated, supplemented with 500 mg of ferric carboxymaltose. Primary outcome measures were haemoglobin levels, C-reactive protein, white blood cell count, transfusion requirements, documented infection and antibiotic treatment. Results: Anaemia was prevalent in 86.2% of patients upon ICU admission. 429 patients were screened for iron deficiency anaemia. 95 patients were eligible, 35 were treated with IVI. An increase of +0.4 g/dl in Hb levels 7 days after IVI compared to -0.1 g/dl in non-treated anaemic patients was observed. The number of RBC transfusions, ICD codes related to infections and infectious parameters were similar between groups. Conclusions: IVI treatment was safe and resulted in higher median Hb levels. Randomized controlled trials are required to support the hypotheses of this study.