Value of Central Venous to Arterial CO2 Difference after Early Goal-directed Therapy in Septic Shock Patients.

Abstract

ABSTRACTBackground and aimsVenous to arterial difference of carbon dioxide (Pv–aCO2) tracks tissue blood flow. We aimed to evaluate if Pv–aCO2 measured from a superior central vein sample is a prognostic index (ICU length of stay, SOFA score, 28th mortality rate) just after early goal-directed therapy (EGDT)comparing its ICU admission values between patients with normal and abnormal (>6 mm Hg) Pv–aCO2. As secondary objectives, we evaluated the relationship of Pv–aCO2 with other variables of perfusion during the 24 hours that followed EGDT.Materials and methodsProspective observational study conducted in an academic ICU adult septic shock patients after a 6-hour complete EGTD. Hemodynamic measurements, arterial/central venous blood gases, and arterial lactate were obtained on ICU admission and after 6, 18 and 24 hours.ResultsSixty patients were included. Admission Pv–aCO2 values showed no prognostic value. Admission Pv–aCO2 (ROC curve 0.527 [CI 95% 0.394 to 0.658]) values showed low specificity and sensitivity as predictors of mortality. There was a difference observed in the mean Pv–aCO2 between nonsurvivors (NS) and survivors (S) after 6 hours. Central venous oxygen saturation (ScvO2) and Pv–aCO2 showed significant correlation (R2 = –0.41, P < 0.0001). Patients with normal ScvO2 (>70%) and abnormal Pv–aCO2 (>6 mm Hg) showed higher SOFA scores. Normal Pv–aCO2 group cleared their lactate levels in comparison to the abnormal Pv–aCO2 group.ConclusionIn septic shock, admission Pv–aCO2 after EGDT is not related to worse outcomes. An abnormal Pv–aCO2 along with a normal ScvO2 is related to organ dysfunction.How to cite this articleAraujo DT, Felice VB, Meregalli AF, Friedman G. Value of Central Venous to Arterial CO2 Difference after Early Goal-directed Therapy in Septic Shock Patients. Indian J Crit Care Med 2019;23(10):449–453.