European Journal of Cardiovascular Medicine

The fact that normal or elevated central venous oxygen saturation (ScvO₂) levels are unable to determine whether tissue perfusion is sufficient, it has been suggested to incorporate additional indicators of tissue hypoxia, such as the central venous-to-arterial carbon dioxide difference (PcvaCO₂ gap). This study aimed to assess the predictive capability of the PcvaCO₂ gap and the PcvaCO₂/CavO₂ ratio in determining the changes in lactate levels in patients with septic shock. The current investigation was carried out at the Medical ICU, emergency medicine, Apollo institute of medical sciences, Hyderabad. Telangana, India, over a period of 30 months from December 2019 to December 2022.This study was a prospective study. Our study found that among septic shock patients, those with elevated PcvaCO2/CavO2 ratio values, even after normalizing MAP and ScvO2 values, were more likely to have a failure in lactate clearance in the subsequent hours. This failure in lactate clearance was related with higher fatality rates in these patients. In our investigation, we found that only the parameter Lactate showed statistical significance, whereas the other parameters did not. The baseline lactate levels in the improver group were lower in comparison to the non-improvers group. Among septic shock patients with normalized mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2), the occurrence of increased PcvaCO2/CavO2 ratio values substantially decreased the likelihood of achieving sufficient lactate clearance in the subsequent hours. Incorporating this parameter into future resuscitation algorithms could be beneficial for obtaining immediate data on the sufficiency of tissue perfusion. This information would assist in the decision-making process, such as determining when to continue resuscitation efforts and when to cease interventions, even in the presence of elevated lactate levels.