Objective: To assess whether end-tidal carbon dioxide partial pressure (PETCO2) can predict the fluid responsiveness in septic shock patients.
Methods: Septic shock patients under mechanical ventilation without spontaneous breathing and with the need of a fluid challenge test were included in this study.Heart rate, central venous pressure, pulse pressure, PETCO2, and CI before and after the fluid challenge test were conducted in all the patients.
Results: Of the 48 septic shock patients included, 34 had preload responsiveness, 14 had no responsiveness. ΔCI and ΔPETCO2 after the fluid challenge test in "volume responders" were (0.85 ± 0.47) L×min(-1)×m(-2) and (3.5 ± 2.5) mmHg respectively, which were higher than those in "no volume responders"(P < 0.05). The fluid-induced changes in PETCO2 and CI were correlated (r = 0.072, P < 0.05). The AUCROC of fluid challenge-induced ΔPETCO2 as the predictor for volume responsiveness was 0.943, and its sensitivity was 87.9% and specificity was 93.4% with a critical value of 5%. The AUCROC of ΔPP as the predictor for volume responsiveness was 0.801, and its sensitivity was 68.1% and specificity was 73.2% with a critical value of 10%.
Conclusion: The changes of PETCO2 induced by a fluid challenge test can predict fluid responsiveness with reliability, and have a better sensitivity and specificity than the changes of PP.