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.

Reduced ferritin levels in individuals with non-O blood group: results from the Danish Blood Donor Study.

BACKGROUND: Genomewide association studies have reported alleles in the ABO locus to be associated with ferritin levels. These studies warrant the investigation of a possible association between the ABO blood group and ferritin levels. We aimed to explore if ABO blood group is associated with iron stores expressed as ferritin levels. STUDY DESIGN AND METHODS: Ferritin levels were measured at least once for 30,595 Danish Blood Donor Study participants. Linear regression analyses were performed with the ABO blood group as explanatory variable and adjusted for age, number of donations 3 years before the ferritin measurement, and time since latest donation. In addition, a subanalysis was performed on 15,280 individuals in which further adjustments for body mass index, smoking status, and C-reactive protein levels were possible. Furthermore, logistic regression analyses were performed to determine if ABO blood group was associated with a ferritin level of less than 15 ng/mL. RESULTS: Non-O blood group donors had lower ferritin levels than blood group O donors, regardless of sex. Accordingly, risk of ferritin level of less than 15 ng/mL was increased for individuals with non-O blood group compared with O blood group. In subanalyses similar associations were observed, albeit in women the association between blood group and risk of a ferritin level below 15 ng/mL was no longer significant. ABO blood group was not associated with red blood cell indices such as mean cell volume and mean cell hemoglobin content. CONCLUSION: Donors with non-O blood group have lower ferritin levels than donors with other blood groups.