Goal of Study:To compare AKI development and tissue oxygenation by evaluating ScvO2, lactate,venoarterial PCO2 difference(ΔPCO2) in minimally transfused and non-transfused cardiac surgery patients.
Materials and Methods:One hundred twentyseven ASA I-II elective coronary artery and valvular heart surgery patients without major intraoperative complications were included in this prospective nonrandomized study. Blood transfusions were driven primarily by hemoglobin levels (7.0 g/dL during cardiopulmonary bypass(CPB) and 8.0g/dL at other times). Patients were divided into two groups:Minimally(1-2 U) Transfused(Group T) and Non-Transfused(Group NT). ScvO2, lactate, ΔPCO2 levels were evaluated after anesthesia induction(T1) and at the end of the operation(T2) and compared between the groups.Postoperative Grade I AKI was defined as increase in serum creatinine of more than or equal to 0.3 mg/dl.The lengths of mechanical ventilation and ICU period, development of Grade I AKI and 28 days mortality
were recorded and compared between the groups. Chi-square, Fisher’s Exact, Student’s T, Paired samples T, Mann Whitney-U, Wilcoxon Signed ranks tests were used to compare categoric and scale variables between two groups for statistical analysis.
Results and Discussion:The operation, CPB, cross clamp times,hemodynamic variables,urine output were similar between two groups.Increment rate of lactate and ΔPCO2 levels in Group T were significantly higher than those levels in Group NT. Twentytwo patients (17.5%) showed AKI and 4 patients (3.1%) died in hospital. Group T patients had more (28,0%) postoperative AKI without statistically significance. Hospital mortality in Group T was higher than those Group NT with siginificant difference(p=0.024). Patients with lactate ≥2 mmol/L at the end of operation showed more AKI than those patients with normal lactate (24.2%
vs 9.1%, respectively; p=0.030). Lactate, ΔPCO2, ScvO2 levels showed good correlation for the development of AKI in both groups.
Conclusions:We concluded that intraoperative anemia that is treated with 1-2 units of blood transfusion causes impairment of tissue oxygenation and increases risk of postoperative AKI in cardiac surgery.Impairment of renal tissue oxygenation may be one of the possible mechanisms for the development of postoperative AKI.

11 / The difference between tissue oxygenation markers and development of acute kidney injury in minimally  transfused and non-transfused cardiac surgery patients.