In this study, investigated the hemodynamic differences between patients who underwent acute normovolemic hemodilution during the Autologous Blood Collection procedure in coronary artery bypass graft surgery and those who did not, using hemodynamic and cardiac data obtained by MostCare's pressure recording analytical method (PRAM).

Coronary artery bypass graft (CABG) surgeries are surgeries in which the need for blood transfusion is high. Allogeneic transfusion and transfusion-related complications have led researchers to use different techniques. Autologous blood collection method is one of the alternative methods used to eliminate the need for transfusion. The acute normovolemic hemodilution technique traditionally applied during autologous blood collection causes hemodilution in CABG surgeries and increases the risk of bleeding in patients. In this study, vasopressor infusion technique was used as an alternative technique to avoid hemodilution during autologous blood collection. These two techniques (Acute normovolemic hemodilution - Vasopressor infusion) applied to maintain hemodynamic stabilization during autologous blood collection were compared with the advanced cardiac and hemodynamic data provided by the pressure recording analytical method. The primary aim of the study was to compare cardiac cycle efficiency (CCE), which is a cardiac performance parameter and provides estimates of the energy spent by the cardiovascular system to maintain hemodynamic balance. Secondary objectives are to compare other advanced hemodynamic and postoperative laboratory parameters.

Inclusion Criteria:

• Age at least 18 years
• Undergoing isolated coronary artery bypass grafting surgery under general anesthesia
• Invasive blood pressure (radial or femoral) and Mostcare monitoring
• Recruitment after booking for surgery with sufficient time to read, understand and question study patient information prior to attending for surgery
• Ability and willingness to provide informed consent

Exclusion Criteria:

• Refuse to consent to the study
• Arterial wave form distortion
• Cardiac arrhythmia
• Inappropriate identification of the dicrotic notch for any reason
• Hemodynamic instability defined as mean arterial blood pressure < 65 mmHg
• Preoperative requirement of inotrope/vasopressor infusion
• Preoperatively receiving vasoactive drugs
• Patients fitted with an intra-aortic balloon pump
• Patients fitted with Extracorporeal Membrane Oxygenation
• Critically ill patients requiring preoperative intensive care unit
• Presence of intraabdominal hypertension
• New York Heart Association Class 3-4 heart failure
• Congestive heart failure with ejection fraction < 35%
• Glomerular filtration rate < 30 ml/min/1.73 m2
• Ongoing renal replacement therapy