The Effect of Perioperative Iron Therapy in Acute Major Non-cardiac Surgery on Allogenic Blood Transfusion and Postoperative Haemoglobin Levels: A Systematic Review and Meta-analysis.

BACKGROUND: Perioperative anaemia in relation to surgery is associated with adverse clinical outcomes. In an elective surgical setting, it is possible to optimize patients prior to surgery, often by iron supplementation with correction of anaemia. Possibilities for optimization prior to and during acute surgical procedures are limited. This review investigates whether iron treatment initiated perioperatively improves outcomes in patients undergoing major acute non-cardiac surgery. METHOD: This systematic review was performed using PubMed, EMBASE (Ovid) and Scopus to identify current evidence on iron supplementation in acute surgery. Primary outcomes were allogenic blood transfusion (ABT) rate and changes in haemoglobin. Secondary outcomes were postoperative mortality, length of stay (LOS), and postoperative complications. Iron was administered at latest within 24 h after end of surgery. RESULTS: Of the 5413 studies screened, four randomized controlled trials and nine observational cohort studies were included. Ten studies included patients with hip fractures. A meta-analysis of seven studies showed a risk reduction of transfusion (OR = 0.35 CI 95% (0.20-0.63), p = 0.0004, I2 = 66%). No influence on plasma haemoglobin was found. Postoperative mortality was reduced in the iron therapy group in a meta-analysis of four observational studies (OR 0.50 (CI 95% 0.26-0.96) p = 0.04). No effect was found on LOS, but a reduction in postoperative infection was seen in four studies. CONCLUSIONS: This review examined perioperative iron therapy in acute major non-cardiac surgery. IV iron showed a lower 30-day mortality, a reduction in postoperative infections and a reduction in ABT largely due to the observational studies. The review primarily consisted of small observational studies and does not have the power to formally recommend this practice.