The Effect of Combined Iron Protocols on Perioperative Allogeneic Transfusion

• Hypothesis:The combined protocol of preoperative sucrose iron, human erythropoietin, and vitamin C will demonstrate superiority in reducing perioperative allogeneic red blood cell (RBC) transfusion volume compared to standard care in patients with iron deficiency anemia undergoing major cardiac surgery with cardiopulmonary bypass.
• Interventions 2.1.Experimental group: Patients in the experimental group will receive a combination therapy consisting of intravenous sucrose iron (200 mg), subcutaneous recombinant human erythropoietin (150 IU/kg), and intravenous vitamin C (2 g), administered once daily for three consecutive days within the week prior to surgery.

2.2.Control group: Routine perioperative management based on clinical judgment, including observation, monitoring, and standard nursing practices.

• Primary endpoint: Total volume of allogeneic RBC transfusion (units) from surgery initiation to postoperative day 5.
• Stratification in randomization: Stratification factors include types of surgery, preoperative baseline hemoglobin level.
• Follow-up time important points include: baseline upon hospital admission, the morning of surgery, postoperative day 1, postoperative day 5, at discharge, 30 ± 7 days after surgery, and 90 ± 7 days after surgery.
• All perioperative transfusion decisions will follow standardized restrictive transfusion thresholds. When the patient's hemoglobin concentration falls below the threshold of 70 g/L during surgery or ICU monitoring, or below 70-80 g/L in the general ward, and/or when signs of anemia or hemodynamic instability are present-including shock, severe arrhythmias, respiratory distress, heart rate >120 beats/min, systolic blood pressure (SBP) <80 mmHg, mean arterial pressure (MAP) <55-60 mmHg, or a reduction in SBP or MAP exceeding 25% from baseline-these findings may indicate significant hypovolemia and warrant consideration of transfusion intervention.

Inclusion criteria

• Participants must be at least 18 years of age.
• Major cardiac surgery should encompass procedures such as coronary artery bypass grafting (CABG), valve surgery, or a combination of both.
• Iron deficiency anemia is defined as having a ferritin level below 100 μg/L or a ferritin level below 300 μg/L accompanied by a transferrin saturation below 25%. Additionally, hemoglobin levels should range between 90 and 130 g/L for men or between 90 and 120 g/L for women.
• The American Society of Anesthesiologists (ASA) classification should fall within Grade 1-3.
• Prior to participation, the patient or their legal representative must provide informed consent.

Exclusion criteria

• Contraindications for the administration of iron sucrose, ascorbic acid, or rHuEPO.
• Presence of a temperature exceeding 37.5 °C or the utilization of non-prophylactic antibiotics.
• Individuals with a weight equal to or less than 50kg.
• Individuals with a family history of haemochromatosis or thalassaemia, or those with a transferrin saturation level exceeding 50% or a documented history of iron overload.
• Presence of other known haematological disorders such as folic acid or vitamin B12 deficiency, haemolytic anaemia, haemoglobinopathies, iron granulocytic anaemia, G6PD deficiency, etc.
• Requirement for emergency surgical intervention.
• Severe hepatic or renal impairment, ALT >3 times the upper limit of normal value or AST >3 times the upper limit of normal value, creatinine >1.5 times the upper limit of normal value
• Pregnant or lactating women
• history of blood transfusion, intravenous iron or ascorbic acid use within 12 weeks prior to surgery
• Acute blood loss, gastrointestinal bleeding, etc. in the preoperative period.