Scoliosis is a condition in which there is curvature of the spine occurring in the lateral plane. It occurs in structural forms, characterized by a fixed curve, and "functional" forms, characterized by a flexible or correctable curve. By anatomic necessity, this lateral deviation is associated with vertebral rotation, such that when this deformity occurs in the thoracic spine, a chest wall deformity, or "rib hump," develops.

Often there is a primary structural curve with an adjacent secondary compensatory curve. Most cases of structural scoliosis are idiopathic and have their onset in early adolescence. Females are affected more often than males, and their curvature is more likely to worsen.

Lumbar fusion surgery is usually associated with massive blood loss. In clinical practice the surgeon might measure the visible peri-operative bleeding including intra- and post-operative drainage, but ignore blood component penetration into the tissues, residual blood in vertebral canal and loss due to haemolysis, which are also known as hidden blood loss.

In patients with adolescent idiopathic scoliosis (AIS), surgical treatment involves a posterior approach with multi-segmental pedicle screw fixation. Although this procedure is generally considered safe with few surgical complications, there are considerable variations in fusion length, surgical time, and the extent of soft-tissue exposure. Consequently, perioperative blood loss can be substantial, and the use of intraoperative and postoperative RBC transfusions are frequently required.

Patient blood management (PBM) is an evidence-based, multidisciplinary approach developed over the last 10 years focusing on improving patient outcomes as well as reducing the use of RBC transfusions. PBM includes several preventive measures to manage bleeding risks, reduce iatrogenic blood loss, and modify decision thresholds for the appropriate administration of blood therapy.

All patients for elective surgery in whom blood loss is expected to be > 500 ml should have their hemoglobin checked pre-operatively and be investigated if they are found to be anemic. In the general population, anemia is defined as a hemoglobin less than 130 g. in men and less than 120g. in women by the WHO. It was proposed that the cut-off value/trigger be changed to hemoglobin more than 130 g for both men and women. Women with hemoglobin levels between 120 and 129 g. are not considered to be anemic according to the WHO definition, leaving them at a potential disadvantage when undergoing major surgery

44 Patients will be randomly classified into two equal groups each of 22 patients Group I: Patients of this group received Combination treatment consisted of a slow (30 min) intravenous infusion of 20 mg/kg ferric carboxymaltose (maximum of 1000 mg), 40 000 U subcutaneous α erythropoietin,1 mg subcutaneous vitamin B12(, and 5 mg oral folic acid (acidum folicum) Group II: Patients of this group received placebo treatment consisted of two subcutaneous injections of 1 mL saline and an oral placebo. Either iron or placebo (0•9% saline) were given intravenously via a black infusion set from behind a screen to assure blinding of the patient by a person not involved in data capturing or data entering.

Patient's vital signs will be monitored during and at least 15 min after drug application. Treatment will be given one day before the operation

Measurements:

1. Demographic data
2. The number of RBC transfusions during the first 7 days.
3. Perioperative course of Hb, (reticulocyte count, reticulocyte Hb content).
4. The need of fresh frozen plasma units transfused in first 7 days
5. The need of platelets units transfused in first 7 days
6. Platelet count.
7. Total leucocyte counts.
8. International normalized ratio.
9. Serum creatinine.
10. C-reactive protein,
11. Calculated RBC loss (preoperative RBC mass minus RBC mass at postoperative fifth day plus transfused RBC mass)
12. Length of ICU stay.
13. Incidence of acute kidney injury
14. Infections requiring antibiotics

Inclusion Criteria:

• patients with idiopathic adolescent scoliosis
• patients with anemia (haemoglobin concentration (Hb) <12g/dL in women and Hb <13 g/dL in men)
• patients with isolated iron deficiency (ferritin <100 mcg/L, no anemia)

Exclusion Criteria:

1. Impairments, diseases (renal &/ hepatic) or language problems which do not allow the patient to fully understand the consequences of study participation
2. Known allergy against iron - carboxymaltose
3. Hemoglobin concentration (Hb) <90 g/L in both male and female)