Intravenous Iron for Correction of Anaemia After Colorectal Surgery

The Aim: to assess the effect of treatment of preoperative anaemia with intravenous iron on haematological parameters for patients after elective colorectal surgery. Primary Hypothesis: postoperative treatment with intravenous iron increases the levels of haemoglobin, ferritin, red cell count and is superior compared to placebo. Secondary effects: treatment with intravenous iron vs placebo provides reduction of blood transfusions, postoperative complications and hospital stay. The Objectives: 1. To estimate the rate of preoperative anaemia in patients of elective colorectal surgery. 2. To assess the dynamic changes of total blood count values in colorectal surgery patients treated with postoperative intravenous iron. 3. To compare the changes in total blood count values over time in colorectal surgery patients treated with intravenous iron versus colorectal surgery patients of the control group. Methods: The prospective, double-blinded study includes American Society of Anaesthesiology (ASA) I-III patients, aged 18-75 years, admitted for elective colorectal surgery. Preoperatively, patients with levels of haemoglobin 90-120 g/l will be identified and their serum ferritin will be tested. In cases of ferritin\<100 mkg/l, patients will be blindly randomized into one of the two groups: treatment group (group T) is given 1000 mg of intravenous iron (iron isomaltoside, Orivas, Pharmacosmos) in the postoperative recovery ward and control group (group C) which is given the same volume of intravenous saline (placebo). Patients in both groups will be provided with general anaesthesia (fentanyl, propofol, atracurium, inhaled sevoflurane for maintenance) and after tracheal extubation will be transferred to the recovery ward. Patient blood tests: total blood count, haemoglobin, haematocrit, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), plasma ferritin) will be assessed in both groups 1 day preoperatively, day 1 and 3 postoperatively, the day of discharge and 4 weeks after discharge from the department of surgery. The level of reticulocyte and reticulocyte haemoglobin concentration will be determined on the day of discharge and 4 weeks after discharge. According to the study protocol, groups will also be compared in terms of clinical recovery, requirements of intravenous fluids and blood transfusion and duration of hospital stay.