Metabolic Profile and Tissue Perfusion in Patients Undergoing Open Heart Surgery With Minimal Invasive Versus Conventional Extracorporeal Circulation

Study of Metabolic Profile and Tissue Perfusion in Patients Undergoing Open Heart Surgery With Minimal Invasive Versus Conventional Extracorporeal Circulation. Randomized Study

The aim of the present study is to investigate the protective effect of minimal invasive versus the conventional extracorporeal circulation on tissue homeostasis as evidenced by the preservation of tissue metabolism and cerebral perfusion.

The aim of the present study is to investigate the protective effect of minimal invasive versus the conventional extracorporeal circulation on tissue homeostasis as evidenced by the preservation of tissue metabolism and cerebral perfusion. Seventy patients undergoing coronary artery bypass grafting, aortic valve replacement or both procedures will be included in the study. Patients will be randomized in two groups: patients operated with the contemporary minimal invasive extracorporeal circulation (study group) versus patients operated with conventional extracorporeal circulation (control group). All patients will be operated according to the same anesthetic and perfusion protocol. During extracorporeal circulation, the following parameters will be recorded:

• real-time tissue metabolism as indicated by oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction ratio (O2ER), CO2 consumption (VCO2), arterial and mixed venous saturation (SvO2)
• blood lactate levels at defined intervals
• real time cerebral oximetry (rSO2) using near-infrared spectroscopy (NIRS) The protective effect of minimal invasive extracorporeal circulation will be evidenced with comparative analysis of metabolic parameters between the two study groups. Real-time tissue metabolic parameters will be further associated with clinical data collected during hospital stay including postoperative morbidity and mortality, major adverse cardiac events, acute renal failure, re-intubation, need for prolonged mechanical ventilation (> 48 hours), re-operation, postoperative bleeding, need for blood product transfusion, ICU and total hospital stay.

Inclusion Criteria:

• patients undergoing undergoing open heart surgery with accepted indications under extracorporeal circulation

Exclusion Criteria:

• need for emergency surgery
• surgery on the thoracic aorta
• severe co-morbities causing anemia, immunosuppression etc.
• immunocompromised patients
• inability to give informed consent