Introduction: Central venous oxygen saturation has inevitable limitation when it serves as a goal of fluid resuscitation. The objective of this study was to assess the capacity of central venous-to-arterial carbon dioxide difference (P(cv-a)CO2) as a complementary marker to guide fluid resuscitation when ScvO2 has reached its threshold in septic shock patients.
Methods: This is a singel-central, observational study of septic shock patient. Patients were randomly divided into two groups with ScvO2 normalized and both ScvO2 and P(cv-a)CO2 normalized as a target of fluid resuscitated respectively. Compared the variables at the beginning of study (T0) and 6 h after fluid resuscitated (T6) for both groups. Lactate clearanc were calculated, and dose of vasoactive drugs, duration of mechanical ventilation and ICU stay and 28-day mortality were recorded.
Results: 68 septic shock patients were included in study. At T0, no defference were found between the two groups. Heart rate and lactic acid decreased significantly at T6 in both groups, but lactate clearance rate of ScvO2+P(cv-a)CO2 group (30.1 ± 17.2) were significantly higher than ScvO2 group (21.6 ± 14.3) (p<0.05). Mechanical ventilation time and duration of ICU stay of ScvO2+P(cv-a)CO2 group were shorter than ScvO2 group (11.7 ± 4.9 days vs. 14.7 ± 6.2 days and 9.3 ± 4.4 days vs. 13.2 ± 6.2 days respectively). No significant difference was observed in 28-days mortality for the two groups.
Conclusion: P(cv-a)CO2 is a valuable complementay goal to guide the fluid resuscitation for septic shock patients. The inclusion of P(cv-a)CO2 into resuscitation protocol would be a safely and effectively practice. But P(cv-a)CO2 may not availably enough to serve as a predictor of prognosis and mortality.