THE CORRELATION BETWEEN CENTRAL VENOUS AND ARTERIAL CARBON DIOXIDE DIFFERENCE (PCO2 GAP) WITH CARDIAC OUTPUT IN EARLY SEPSIS A PROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background: Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection, occurs when chemicals cause a cascade of changes that damage multiple organ systems, leading to failure and sometimes even death.This study aimed to evaluate the prognostic significance of the PCO2 gap on cardiac output during early sepsis.

Methods: This prospective observational study was conducted on 224 patients admitted with a diagnosis of sepsis according to the international guidelines of the Department of Anesthesiology, SRM Medical College Hospital and Research Centre, between 2022 and May 2023.The PCO2 gap was measured from the arterial blood gas (ABG) and the difference between PaCO2 in the ABG and PVCO2 in the venous sample.

Results: Cardiac output was significantly higher in the high PCO2 gap group (p =0.0367 and p = 0.0315, respectively).The cardiac index was significantly higher in the low PCO2 gap group at 0 h (p=0.0067) and 6 h (p=0.0082).There was no significant difference between the PCO2 gap and the serum lactate and vasopressor requirements.There was a significant relationship between IV fluid requirement and the PCO2 gap at 0 h (p=0.0039) but not at 6 h (p=0.5773).There was a positive correlation between MAP and PCO2 gap at baseline and at 6 h.There was a negative correlation between the PCO2 gap and serum lactate, intravenous fluids, and vasopressor requirements.

Conclusion: The PCO2 gap can be used as an index to assess the severity of sepsis and its progression since it directly correlates with cardiac index and cardiac output.