Effectiveness of Preoperative Iron Supplementation in Major Surgical Patients With Iron Deficiency: A Prospective Observational Study.

OBJECTIVE: To evaluate the effectiveness of routine intravenous iron in surgical patients with iron deficiency anemia (IDA). BACKGROUND: Anemia is the most common medical disease in the world and is an independent risk factor for morbidity and mortality. Iron deficiency (ID) is the main cause for anemia and constitutes a potentially preventable condition with great impact on surgical outcome. METHODS: In this prospective single-center observational study, surgical patients were screened for the presence of anemia and ID. Patients were assigned to 1 of 4 study groups: A- (no anemia); A-, ID+, T+ (no anemia, iron-deficient, iron supplementation); A+ (anemia); and A+, ID+, T+ (anemia, iron-deficient, iron supplementation) according to hemoglobin level, iron status, and supplementation with iron. RESULTS: Among 1728 patients, 1028 were assigned to A-; 55 to A-, ID+, T+; 461 to A+; and 184 to A+, ID+, T+. While all iron-supplemented IDA patients required less red blood cell (RBC) transfusion during the postoperative period (A+ 42.5% vs A+, ID+, T+ 31.5%), a reduced intraoperative transfusion rate was observed for ID and IDA patients only if iron was supplemented >7 days before surgery. Hospital stay was significantly reduced by 2.8 days in iron-supplemented patients (P < 0.01 comparing 13.9 ±â€Š0.8 days for A+, ID+, T+ vs. 16.7 ±â€Š0.7 days for A+). CONCLUSION: Preoperative IDA management with intravenous iron is effective in improving hemoglobin level, thereby reducing intraoperative RBC transfusion rate particular if iron is administrated >7 days before surgery. Hospital length of stay was reduced in all preoperatively iron-supplemented IDA patients.

Screening for iron deficiency in surgical patients based on noninvasive zinc protoporphyrin measurements.

BACKGROUND: Approximately every third surgical patient is anemic. The most common form, iron deficiency anemia, results from persisting iron-deficient erythropoiesis (IDE). Zinc protoporphyrin (ZnPP) is a promising parameter for diagnosing IDE, hitherto requiring blood drawing and laboratory workup. STUDY DESIGN AND METHODS: Noninvasive ZnPP (ZnPP-NI) measurements are compared to ZnPP reference determination of the ZnPP/heme ratio by high-performance liquid chromatography (ZnPP-HPLC) and the analytical performance in detecting IDE is evaluated against traditional iron status parameters (ferritin, transferrin saturation [TSAT], soluble transferrin receptor-ferritin index [sTfR-F], soluble transferrin receptor [sTfR]), likewise measured in blood. The study was conducted at the University Hospitals of Frankfurt and Zurich. RESULTS: Limits of agreement between ZnPP-NI and ZnPP-HPLC measurements for 584 cardiac and noncardiac surgical patients equaled 19.7 µmol/mol heme (95% confidence interval, 18.0-21.3; acceptance criteria, 23.2 µmol/mol heme; absolute bias, 0 µmol/mol heme). Analytical performance for detecting IDE (inferred from area under the curve receiver operating characteristics) of parameters measured in blood was: ZnPP-HPLC (0.95), sTfR (0.92), sTfR-F (0.89), TSAT (0.87), and ferritin (0.67). Noninvasively measured ZnPP-NI yielded results of 0.90. CONCLUSION: ZnPP-NI appears well suited for an initial IDE screening, informing on the state of erythropoiesis at the point of care without blood drawing and laboratory analysis. Comparison with a multiparameter IDE test revealed that ZnPP-NI values of 40 µmol/mol heme or less allows exclusion of IDE, whereas for 65 µmol/mol heme or greater, IDE is very likely if other causes of increased values are excluded. In these cases (77% of our patients) ZnPP-NI may suffice for a diagnosis, while values in between require analyses of additional iron status parameters.