title: Role of preoperative intravenous iron therapy to correct anemia before major surgery: study protocol for systematic review and meta-analysis.
abstract: BACKGROUND
  Preoperative anemia is a common and potentially serious hematological problem in elective surgery and increases the risk for perioperative red blood cell (RBC) transfusion. Transfusion is associated with postoperative morbidity and mortality. Preoperative intravenous (IV) iron therapy has been proposed as an intervention to reduce perioperative transfusion; however, studies are generally small, limited, and inconclusive.
  
  
  METHODS
  We propose performing a systematic review and meta-analysis. We will search MEDLINE, EMBASE, EBM Reviews, Cochrane-controlled trial registry, Scopus, registries of health technology assessment and clinical trials, Web of Science, ProQuest Dissertations and Theses, and conference proceedings in transfusion, hematology, and surgery. We will contact our study drug manufacturer for unpublished trials. Titles and abstracts will be identified and assessed by two reviewers for potential relevance. Eligible studies are: randomized or quasi-randomized clinical trials comparing preoperative administration of IV iron with placebo or standard of care to reduce perioperative blood transfusion in anemic patients undergoing major surgery. Screening, data extraction, and quality appraisal will be conducted independently by two authors. Data will be presented in evidence tables and in meta-analytic forest plots. Primary efficacy outcomes are change in hemoglobin concentration and proportion of patients requiring RBC transfusion. Secondary outcomes include number of units of blood or blood products transfused perioperatively, transfusion-related acute lung injury, neurologic complications, adverse events, postoperative infections, cardiopulmonary complications, intensive care unit (ICU) admission/readmission, length of hospital stay, acute kidney injury, and mortality. Dichotomous outcomes will be reported as pooled relative risks and 95% confidence intervals. Continuous outcomes will be reported using calculated weighted mean differences. Meta-regression will be performed to evaluate the impact of potential confounding variables on study effect estimates.
  
  
  CONCLUSIONS
  Reducing unnecessary RBC transfusions in perioperative medicine is a clinical priority. This involves the identification of patients at risk of receiving transfusions along with blood conservation strategies. Of potential pharmacological blood conservation strategies, IV iron is a compelling intervention to treat preoperative anemia; however, existing data are uncertain. We propose performing a systematic review and meta-analysis evaluating the efficacy and safety of IV iron administration to anemic patients undergoing major surgery to reduce transfusion and perioperative morbidity and mortality.
  
  
  BACKGROUND
  PROSPERO CRD42015016771.
authors: School of Public Health, University of Alberta, 4075 RTF, 8308 114 Street, Edmonton, Alberta, T6G 2E1, Canada. a_elhenawy@hotmail.com.
authors: Abdelsalam M
authors: AM
authors: Elhenawy
authors: Division of Cardiac Surgery, Department of Cardiac Surgery, Faculty of Medicine and Dentistry, University of Alberta, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada. srmeyer@ualberta.ca.
authors: Steven R
authors: SR
authors: Meyer
authors: Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, 2-124 Clinical Sciences Building 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada. bagshaw@ualberta.ca.
authors: Sean M
authors: SM
authors: Bagshaw
authors: Division of Cardiac Surgery, Department of Cardiac Surgery, Faculty of Medicine and Dentistry, University of Alberta, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada. roderick.macarthur@albertahealthservices.ca.
authors: Roderick G
authors: RG
authors: MacArthur
authors: School of Public Health, University of Alberta, 4075 RTF, 8308 114 Street, Edmonton, Alberta, T6G 2E1, Canada. lcarroll@ualberta.ca.
authors: Linda J
authors: LJ
authors: Carroll
mesh_terms: D061605:Administration, Intravenous; D000740:Anemia / Q000188:drug therapy* / Q000378:metabolism; D002985:Clinical Protocols; D017707:Erythrocyte Transfusion; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000627:therapeutic use*; D007902:Length of Stay; D011183:Postoperative Complications / Q000517:prevention & control*; D011300:Preoperative Care; D012107:Research Design; D000078202:Systematic Reviews as Topic
chemical_list: D006454:Hemoglobins; D007501:Iron