Role of preoperative intravenous iron therapy to correct anemia before major surgery: study protocol for systematic review and meta-analysis
Protocol
1 School of Public Health, University of Alberta, 4075 RTF, 8308 114 Street, Edmonton T6G 2E1, Alberta, Canada
2 Division of Cardiac Surgery, Department of Cardiac Surgery, Faculty of Medicine and Dentistry, University of Alberta, 8440-112 Street, Edmonton T6G 2B7, Alberta, Canada
3 Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, 2-124 Clinical Sciences Building 8440-112 Street, Edmonton T6G 2B7, Alberta, Canada
Systematic Reviews 2015, 4:29Â
doi:10.1186/s13643-015-0016-4
Published: 15 March 2015
Abstract (provisional)
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/design 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 We will contact our study drug manufacturer for unpublished trials.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. Discussion Reducing unnecessary RBC transfusions in perioperative
medicine is a clinical priority. This involves the identification 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. Systematic review registration PROSPERO CRD42015016771