Objectives: Effective assessment of tissue perfusion is highly important during Coronary Artery Bypass Graft (CABG). Mixed venous O2 saturation (SvO2) is one of the best and routinely used markers of tissue perfusion. However, this method is costly and leads to considerable complications. Thus, the present study aimed to determine whether the SvO2 can be substituted with central venous saturation (Scvo2) and if there is any correlation between lactate level and SvO2.Methods: This prospective observational study was conducted on 62 patients scheduled for CABG. After induction and maintenance of anesthesia, blood samples drawn from central venous, pulmonary artery, and radial artery were used to measure Scvo2, SvO2 and serum lactate level respectively before and after Cardio Pulmonary Bypass (CPB). Pearson's correlation test was used to determine the correlation between SvO2 and Scvo2 as well as between SvO2 and serum lactate level. Besides, P<0.05 was considered as statistically significant.Results: Overall, 62 Patients, 33 males (53.2%) and 29 females (46.8%) were enrolled into the present study. The most common coexisting illness was hypertension detected in 33 patients (53.2%) followed by hypercholesterolemia in 28 ones (44.4%). In this study, SvO2 was positively correlated with Scvo2 (r=0.63, P<0.001). However, no correlation was found between SvO2 and lactate (r=0.124, P=0.348).Conclusions: In summary, Scvo2 is considered as the best substitute of SvO2 for detecting tissue hypo perfusion during CPB. Although the lactate level had been considered as an appropriate marker of tissue perfusion and ischemia, it was not correlated to SvO2 during CABG.

Background The change in venous oxygen saturation occurs earlier, and even its reduction is faster than arterial oxygen saturation. The aim of this study was to validate SvO2 and PvO2 for O2 content measurement in children hospitalized with respiratory distress. Materials and Methods In this cross-sectional study, 80 children who were admitted with respiratory distress were included in the study according to the study inclusion and exclusion criteria. Baseline characteristics such as age and gender were recorded in the data collection form, designed by the researcher. In order to determine the amount of SaO2 and PaO2 the arterial blood sample was prepared, venous blood sample was prepared to determine the amount of hemoglobin, SvO2 and PvO2. The gold standard for the determination of O2 content was the arterial blood sample. All samples were examined by a blood gas analyzer and then calculated using the formula of O2 content values. For SvO2 and PvO2 validation, we used diagnostic analysis methods including sensitivity, specificity, positive and negative predictive values. Cut-point value for SvO2 and PvO2 were 76. 50 and 44. 30, respectively. Results In this study, the patients’ mean age was 5. 15 ± 4. 20 years. 62. 5% (n=50) were male and 38. 5% (n=30) were female. The values of arterial and venous O2 content were 14. 13 ± 3. 05 and 11. 95 ± 3. 04 from a total of 80 patients. SvO2 and PvO2 for measuring O2 content had a sensitivity of 80. 5 and 71. 80%, respectively, and specificity of 80. 5 and 78%, respectively. Conclusion SvO2 and PvO2 have good validity for evaluating O2 content in patients admitted to PICU. So that SvO2 had a sensitivity and specificity of over 80%, and PvO2 had a sensitivity and specificity of over 70%.

Introduction: Anemia is to reduce the capacity of oxygen transport by blood. Capacity of oxygen transport is one of the functions of red blood cells, circulatory in blood volume, therefore it can be said that anemia is reduction of red blood cells volume. The problem of this clinical definition is the effect of plasma volume on hematocrit and hemoglobin concentration.Goal: To determine systemic oxygenation criteria.Methods: Study and research on internet and review of literature.Problem Statement: On the condition that intravascular volume is maintained anemia is well tolerated, if blood volume is normal, redaction of hemoglobin to 3gr/dl causes tissue oxygenation disorder. This means that cardiac output is more important than blood hemoglobin levels in order to maintain tissue oxygenation. Superiority to cardiac output becomes more obvious when nature of hypovolemic shock and carcinogenic shock become specified while there is not anemia shock at all. Because shock is accompanied with the decline of tissue oxygenation. So, until anemia reach to dangerous levels it cannot be known as the reason of shock because in mild levels anemia doesn't cause tissue oxygenation disorder. A better criterion for evaluating systemic oxygenation is extraction of peripheral oxygen measured as sao2-SvO2 differences.Conclusion: By accepting this reality, therefore most RBC transfusions to correct anemia status will not improve tissue oxygenation also concentration of hemoglobin is not a valuable criterion in order to evaluate the need for transfusion. A better criterion for evaluating systemic oxygenation is extraction of peripheral oxygen, measured as sao2-SvO2 differences.

Background: Heart diseases are typically treated with cardiac surgery, which often requires preoperative, intraoperative, and postoperative blood transfusion. However, blood transfusion is a risk factor for serious complications after cardiac surgery, including death. Patient Blood Management (PBM) programs were developed to mitigate the risks of blood transfusion by reducing its use in cardiac surgery. Objective: This systematic review aims to study the currently published literature on PBM strategies that effectively reduce the rates of preoperative, intraoperative, and postoperative blood transfusion for cardiac surgery. Methodology: This systematic review analyzed preoperative blood management strategies in cardiac surgery, focusing on studies published between 2018 and 2024 designed to reduce blood transfusion rates. The study utilized a modified 2022 protocol for systematic reviews and meta-analysis, grading evidence using a 2008 system, and selected 21 studies for a systematic review. Results: The studies identified 12 PBM strategies, including iron therapy, Aminocaproic acid, Cardiopulmonary by-pass system, cell salvage, Perfusion Blood Collection, gel foam patches, Large-volume acute normovolemic hemodilution, Platelets Transfusion Therapy, Modified Ultrafiltration, TEM-based algorithms, and restrictive management of SvO2, which significantly reduced blood transfusion volumes and rates before, during, and after cardiac surgery. Conclusion: The 12 PBM strategies identified are valuable additions to the current list, but further clinical evaluation is needed to improve their efficacy and safety in cardiac surgery.