Iron-deficiency Anaemia and Its Impact on Recovery After Colorectal Cancer Surgery

The following erythrocyte indices based on the preoperative complete blood count results will be calculated for each patient one day prior to surgical treatment:

• Mentzer index: MCV / RBC
• Green and King index: MCV2 x RDW / (100 x HGB)
• RDW index: MCV x RDW / RBC
• Shine and Lal index: MCV2 x MCH / 100
• England and Fraser index: MCV - RBC - (5 x HGB) - 3.4
• Srivastava index: MCH / RBC
• Ricerca index: RDW / RBC
• Ehsani index: MCV - (10 x RBC)
• Sirdah index: MCV - RBC - (3 x HGB)
• Sehgal index: MCV2 / RBC

The Ganzoni equation for calculating total iron deficit will be calculated for each patient one day prior to surgical treatment, using the following formula:

total iron deficit [mg] = body weight [kg] x (target hemoglobin [g/L] - actual hemoglobin [g/L]) x 2.4 + iron depot [mg]

Inclusion criteria

• Adult patients (˃ 18 years of age)
• ASA III clinical status
• Patients undergoing radical surgical treatment of colorectal cancer
• Signed written informed consent

Exclusion criteria

• Patients undergoing palliative surgical treatment of colorectal cancer
• Anaemic patients without iron deficiency, defined as: normal serum iron concentration, TSAT, TIBC, UIBC, and decreased HGB, HCT and RBC
• Presence of other type of anaemia than iron deficiency anaemia (e.g. alpha- or beta-thalassemia, sickle-cell anaemia, etc.)
• History of red blood cell transfusion in the period of 120 days prior to hospital-admission
• Stage III, IV, or V of chronic kidney disease (creatinine clearance < 60 mL/min)
• Significant intraoperative bleeding, which requires transfusion of red blood cell products, calculated using the Gross-formula:

allowable blood loss [mL] = (estimated blood volume [mL] x (initial HGB [g/L] - HGB level when transfusion is required [g/L])) / average of initial HGB and HGB level when transfusion is required [g/L] The cut-off value for HGB level when transfusion is required is set to 80 g/L.