Central Venous Oxygen Saturation And Central Venous-to-arterial Carbon Dioxide Difference In Guiding Fluid Resuscitation Of Surgical Septic Shock

Objective:To determine whether central venous-to-arterial carbon dioxide difference (Pcv-aCOa) and Central venous oxygen saturation (ScvO2) could be better guide early fluid resuscitation in surgical septic shock patients.Methods:Forty six postoperative septic shock patients in ICU of the2nd Affiliated Hospital of Kunming Medical University (from Jan2012to Mar2013) were enrolled in this study. They underwent resuscitation through early goal-directed therapy. We calculate whether there were correlations among the ScvO2,P(cv-a)CO2and tissue perfusion index(Lactic acid, Base excess) or blood flow index(Cardiac output), including the beginning of resuscitation(TO) and after6hour resuscitation(T6). And we analyze whether there were correlations between ScvO2and P(cv-a)CO2in TO and T6. Patients were divided into survival group (n=30) and death group (n=16) by the prognosis, compared ScvCO2and P(cv-a)CO2whether there is a statistically significant difference between groups. They were divided into groups according to ScvO2and P(cv-a)CO2.Then the clearance of lactate, mechanical ventilation, ICU stay and28d mortality were compared between the groups. We evaluated the judgment of prognosis by P(cv-a)CO2and compared the differences of28d mortality among groups which divided by ScvO2.Results:There were significant difference among ScvO2, P (cv-a) CO2, lactic acid, base excess in the six hours before and after fluid resuscitation. There was some correlation among ScvO2, P(cv-a)CO2and tissue perfusion index(Lactic acid, Base excess),and there was correlation among ScvO2, P(cv-a)CO2and blood flow index(Cardiac output). ScvO2and cardiac output was positive correlation, and P (cv-a) CO2and cardiac output was negative correlation. ScvO2and P(cv-a)CO2was negatively correlated in TO and T6. Patients were divided into survival group (n=30) and death group (n=16) by the prognosis, there were significant difference among APACHEII score, SOFA score and vasopressor reduction in6hours, and survival groups’ were better than death groups’. After continuous6hour resuscitation, there were significant difference in lactic acid, clearance of lactate, base excess, PaO2/FiO2and creatinine between the two groups, but there was no significant difference in ScvO2(P=0.104) All enrolled patients who had ScvO2greater than70%after6hour early resuscitation, they were divided into two groups, based on whether the patients’T6P(cv-a)CO2was less than6mmHg (low gap group) or greater than or equal to6mmHg (high gap group).There were significant difference in the clearance of lactate and28d mortality (P=0.018;P=0.001). All enrolled patients who had P(cv-a)CO2lesser than6mmHg after6hour early resuscitation, they were divided into two groups, based on whether the patients’T6ScvO2was less than70%(low gap group) or greater than or equal to70%(high gap group). There was significant difference in the clearance of lactate (P=0.024).All enrolled patients were divided into lower ScvCO2group(<70%),middle ScvO2group(70to80%),and higher ScvO2group(>80%) after6hour early resuscitation, there were no significant difference in28d mortality (x2Value=5.319,P=0.070). T6P (cv-a) CO2also had some prognostic ability (AUROC=0.758).Conclusion:The combination of ScvO2and P(cv-a)CO2may guide the shock resuscitation. The clearance of lactate was the highest in the group of patients achieving the goals of both ScvO2>70%and P(cv-a)CO2<6mmHg. Septic patients targeting only ScvO2may still have inappropriate tissue perfusion, especially when Pcv-aCO2≥6mmHg, which indicates insufficient resuscitation. Combined ScvO2and P(cv-a)CO2to guide resuscitation of septic shock could be avoided to end the treatment earlier, and affect the patient’s prognosis.