The impact of timing of intravenous iron supplementation on preoperative haemoglobin in patients scheduled for major surgery.

BACKGROUND: Anaemia is frequent and an independent risk factor for morbidity and mortality in patients undergoing surgery. Iron deficiency (ID) is the main cause for anaemia and can be corrected by intravenous (IV) iron. The aim of this study was to investigate the timing of preoperative IV iron supplementation on preoperative haemoglobin (Hb) level. MATERIALS AND METHODS: Surgical patients were screened for the presence of anaemia and ID from November 2015 to January 2020. In case of ID or iron deficiency anaemia (IDA), patients received IV iron supplementation. The timing of IV iron supplementation on preoperative Hb level was analysed by days and time frames clustered by 5 days before surgery. RESULTS: In total, 404 patients with IV iron supplementation were analysed. In all patients, IV iron was administered with a median (interquartile range [IQR]) of 3.0 (1.0; 9.0) days before surgery. Preoperative Hb level increased steadily starting from 6 days (0.13 [±1.2] g/dL) until 16 days before surgery (1.75 [±1.1] g/dL). Group comparison revealed a median preoperative Hb change of -0.2 (-0.5; 0.2) g/dL for days 1-5, 0.2 (0.0; 0.7) g/dL for days 6-10, 0.7 (0.2; 1.1) g/dL for days 11-15, 0.7 (0.2; 1.8) g/dL for days 16-20, 0.9 (0.3; 1.7) g/dL for days 21-25, 1.5 (0.4; 2.6) g/dL for days 26-30, and 0.6 (0.0; 1.7) g/dL for >31 days. Three patients received multiple administrations of IV iron which resulted in an increase in Hb of >4 g/dL. DISCUSSION: Supplementation of IV iron to increase Hb concentration preoperatively may be most effective if administered at least ten days before surgery.

The association between intraoperative cell salvage and red blood cell transfusion in cardiac surgery - an observational study in a patient blood management centre.

INTRODUCTION: Cell salvage (CS) is an integral part of patient blood management (PBM) and aims to reduce allogeneic red blood cell (RBC) transfusion. MATERIAL AND METHODS: This observational study analysed patients scheduled for elective cardiac surgery requiring cardiopulmonary bypass (CPB) between November 2015 and October 2018. Patients were divided into a CS group (patients receiving CS) and a control group (no CS). Primary endpoints were the number of patients exposed to allogeneic RBC transfusions and the number of RBC units transfused per patient. RESULTS: A total of 704 patients undergoing cardiac surgery were analysed, of whom 338 underwent surgery with CS (CS group) and 366 were without CS (control group). Intraoperatively, 152 patients (45%) were exposed to allogeneic RBC transfusions in the CS group and 93 patients (25%) in the control group (P < 0.001). Considering the amount of intraoperative blood loss, regression analysis revealed a significant association between blood loss and increased use of RBC units in patients of the control compared to the CS group (1000 mL: 1.0 vs. 0.6 RBC units; 2000 mL: 2.2 vs. 1.1 RBC units; 3000 mL: 3.4 vs. 1.6 RBC units). Thus, CS was significantly associated with a reduced number of allogeneic RBCs by 40% for 1000 mL, 49% for 2000 mL, and 52% for 3000 mL of blood loss compared to patients without CS. CONCLUSIONS: Cell salvage was significantly associated with a reduced number of allogeneic RBC transfusions. It supports the beneficial effect of CS in cardiac surgical patients as an individual measure in a comprehensive PBM program.

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.