Correlation between pulse-wave cerebral tissue oxygen saturation and end-tidal carbon dioxide during cardiopulmonary resuscitation.

INTRODUCTION

There is mounting evidence showing that physiological monitoring of cardiopulmonary resuscitation (CPR) quality is important for achieving high-quality CPR. Cerebral tissue oxygen saturation and end-tidal carbon dioxide (ETCO2) are expected to become useful indicators for CPR quality. To reveal whether pulse-wave cerebral tissue oxygen saturation (SnO2) could be used as an indicator of CPR quality, we investigated the correlation between SnO2 and ETCO2 during CPR.

METHODS

We performed this retrospective observational study to investigate the correlation between cerebral tissue oxygen saturation and ETCO2 during CPR in patients in cardiac arrest who arrived at the emergency division of Yamagata University Hospital. SnO2 and tissue oxygenation index (TOI) were measured as markers of cerebral tissue oxygen saturation.

RESULTS

Twenty-eight patients were included in this study. The correlation coefficients between cerebral tissue oxygen saturation and ETCO2 at 3 min after intubation were 0.586 for SnO2 (p = 0.004) and 0.555 for TOI (p = 0.003). The correlation coefficients between cerebral tissue oxygen saturation and mean ETCO2 were 0.630 for mean SnO2 (p = 0.002) and 0.643 for mean TOI (p < 0.001).

CONCLUSIONS

SnO2 and TOI were positively correlated with ETCO2 during CPR in terms of the mean values and the values recorded at 3 min after intubation. SnO2 can be measured more rapidly than ETCO2, making it useful for assessing CPR quality before intubation or in situations where intubation is not feasible.