From Prehabilitation to Recovery: The Effect of Nutritional Optimization in Anemic Patients Scheduled for Elective Open-Heart Surgery- A Randomized Controlled Trial

Operational Definitions Prehabilitation Prehabilitation is personalized, multimodal and individually-tailored intervention that exclusively meets the patient's requirement targeted to improve physiological and metabolic psychological resilience needed before a major stressful event i.e. the surgery in this case.

Solo Nutritional Prehabilitation It is a dedicated nutrition prehabilitation program which works on identifying the patients' nutritional status and identifying malnutrition preoperatively. It is the early beginning of carefully planned and individually tailor made medical nutrition therapy (MNT) Nutrition Screening This is one of the first step which is done when patient is admitted in the hospital. The purpose is to identify patients who are either at risk of malnutrition or those who are already malnourished and in case of diagnosing malnutrition, intervention can be done quickly.

Nutrition Assessment Nutrition assessment means gathering and evaluating pertinent clinical, physical and nutritional data which includes diet, surgical & medical history, medications and psycho-social factors to identify nutritional problems. In the context of malnutrition, the nutrition assessment aids in recognizing patients who are malnourished and nutritional intervention is indicated.

Frailty Frailty is a syndrome which is identified by increased vulnerability, less resistance, reduced physiological reserve, weakness, low gait speed, fatigue, poor mobility, unintentional weight loss and limited ability to maintain homeostasis after stressful events such as the cardiac surgery, that results in high probability of poor clinical outcomes and mortality.

Immune Modulating Formulas These formulas have specific nutrients that modulate the immune system or stimulate the immune response to achieve optimization of nutritional support is promising adjunctive therapy in the section of perioperative care. They contain arginine, glutamine, omega-3 fatty acids, antioxidants, taurine, vitamins and trace elements, such as zinc and selenium. High protein content of the supplements and agents which have Eicosapentaenoic acid (EPA) & Docosahexaenoic Acid (DHA) are known to enhance the immune system both preoperatively and postoperatively. Immuno-nutrition can be found only in enteral formulas Iron deficiency Anemia (IDF) The World Health Organization (WHO) and The National Institute for Health and Care Excellence (NICE) define anemia when hemoglobin levels drop to 13g/L in men over 15 years of age and below 12g/L in non-pregnant women over 15 years of age RESEARCH METHODOLOGY Sample Size Given the primary outcome of the incidence of transfusion in intra-op and post-op period among cardiac patients undergoing elective CABG and Valvular surgeries receiving iron correction therapy; recent cardiac surgery and pre and post-operative blood management literature suggests that the baseline transfusion rates usually range between 30 to 60%.However, with optimizations such as iron correction therapy among others, a reduction of about 20 to 40% is expected. Given that, using G*Power, the sample size was calculated for comparison of two independent proportions. Based on contemporary evidence on perioperative blood management, a transfusion incidence of 50% in the control group and 25% in the intervention group was assumed. With a two-sided alpha of 0.05 and power of 80%, the required sample size was 64 patients per group. After accounting for a 10% attrition rate, a total of 140 patients (70 per group) will be recruited accordingly.