Comparison between continuous and discontinuous central venous oxygen saturation in the ICU: a prospective study and preliminary results

Introduction

Benefits of central venous oxygen saturation (ScvO₂) optimization, at early stages of severe sepsis and septic shock, have been shown [1]. Discontinuous ScvO₂ measurement has not been studied earlier. The purpose of our study was to compare continuous and discontinuous ScvO₂ in terms of the number of therapeutic interventions in septic patients.

Methods

After approval by our institutional ethics committee, 16 patients with severe sepsis or septic shock were included in this prospective study. Patients were randomly assigned to the continuous ScvO₂ group (central venous catheter; Edwards Lifescience X3820HS) or to the discontinuous ScvO₂ group.

Blood pressure, heart rates and pulse oxymetry were continuously monitored and the lactate concentration measured in all patients. In both groups we noted that the number of therapeutic interventions due to the ScvO₂ value is <70%. Statistical analysis used the Fisher test exact for qualitative variables and the Student t test (Mann–Whitney) for quantitative variables. P < 0.05 was considered significant.

Results

There were no significant differences between the groups with respect to baseline characteristics. The median number of therapeutic interventions was significantly higher in the continuous group (13 vs 7, P = 0.016). No significant differences ScvO₂ occurred between the length of stay in the two groups. See Table 1.

Table 1 Comparison between continuous and discontinuous central venous oxygen saturation

Conclusion

These preliminary results showed that continuous ScvO₂ measurements increase the number of therapeutic interventions. We conclude that continuous measurement of ScvO₂ is helpful for early therapeutic interventions. Controlled trials of sufficient size, however, are needed to confirm these results.