Background: Venous-to-arterial carbon dioxide difference (PvaCO2) and central venous oxygen saturation (ScvO2) may reflect the adequacy of blood flow during septic shock states. We sought to test whether the development of Pv-aCO2 and ScvO2 during the early phases of resuscitation is related to multi-organ dysfunction and outcomes in a population of septic shock patients resuscitated targeting the usual oxygen-derived and hemodynamic parameters. Aim of the Work: To assess the central venous-arterial carbon dioxide difference (Pv-aCO2) as a goal in goal directed therapy of sepsis resuscitation in comparison to central venous oxygen saturation (ScvO2) and to test for their prognostic values. Patients and Methods: This prospective observational study was performed in a 24-bed mixed ICU in a university-affiliated hospital. We examined all septic patients with a new episode admitted to the emergency room or proceeding from clinical wards during a 24-month period. After approval by Ethical Medical Committee and obtaining informed consent, simultaneous blood samples were collected from the central venous line and the arterial catheter for obtaining venous and arterial gases respectively at (T0), and 6 hours (T6), 12 hours (T12) and 24 hours (T24) later. Patients were classified into four groups; two group (30patients) (A1 and A2) according to PcvO2 gap and another two groups (30patients) (B1 and
B2) according to Central venous oxygen saturation. Group (A1) Decreasing Pcv-aCO2 (high at T0, declining at T6), Group (A2) Persistently high Pcv-aCO2 (high at T0 and T6), Group (B1) Increasing Central venous oxygen saturation (less than 70% at T0, increasing at T6), Group (B2) Decreasing Central venous oxygen saturation (less than 70%at T0 and decreasing T6). Results: Sixty-eight septic critically ill patients were included in this study. However; 8 patients were excluded from the study. Among the included patients in the study, 3 patients were excluded as they developed acute coronary syndrome, 4 patients refused to complete the treatment and discharged against medical advice, and 1 patient
developed an ischemic cerebral vascular stroke. The final sample was therefore 60 patients. In this study, Central veno-arterial PCO2 gap and ScvO2 are considered as surrogate markers of the payment of the oxygen debt and early predictors of clinical outcome and organ dysfunction in the ICU. As regard the study, Central veno-arterial PCO2 gap is predictors for resuscitation in septic patients. As regard A Group, there was significant statistical difference between mortality and survival at T6, T12 and T24. However; regarding B Group, there was significant statistical difference between mortality and survival at T12 and T24. Also, this study shows that patients with persistently low ScvO2 are considered a good hypo perfusion marker for septic patients. Conclusion: Data support the hypothesis that persistence of high PCO2 Gap and low ScvO2 during the resuscitation of septic patients is associated with significant higher multi-organ dysfunction and poor outcomes in critically-ill patients. Recommendations: Future studies on a larger number of patients are needed and should test PCO2 Gap and ScvO2 as perfusion goals during early phases of the resuscitation of patients in septic shock to confirm its reliability.