During CPR as it is currently administered, treatments are selected from an algorithm derived by monitoring with ECG alone. One of the reasons for this is that no other devices are presently thought to be effective in helping to make treatment determinations. Monitoring of regional cerebral oxygen saturation with near infrared light is non-invasive and provides information on brain tissue oxygenation and hemodynamics. The results of our study suggest that measurements derived from continuously monitoring regional cerebral oxygen saturation during CPR can be considered an effective method of predicting the ROSC in cardiac arrest patients.
Methods:
In 95 patients with out-of-hospital cardiac arrest, the tissue oxygenation index (TOI) was continuously monitored (NIRO-200NX, Hamamatsu Photonics). We investigated the following parameters with respect to whether or not ROSC was achieved: TOI value at the contact of patients (initial TOI); TOI value just before ROSC (pre-ROSC TOI); and the maximum TOI during CPR (maximum TOI).
Results:
All the patients monitored received treatment with shocks or drugs and the initial TOI was 35.3±7.3%. For 74 patients who did not achieve ROSC, the maximum TOI was 41.0±7.4%, whereas for 21 patients who did achieve ROSC, the pre-ROSC TOI was 51.3±3.6% and the maximum TOI was 64.3±11.4%. ROSC was not achieved in the patients with maximum TOI below 45%.
Conclusion:
The pre-ROSC TOI was significantly higher than the maximum TOI in the patients who did not achieve ROSC which suggests the possibility of predicting ROSC by monitoring the increase in TOI. In cases where the TOI remains low, there is a possibility that ROSC should not be expected. In such cases, it may be desirable to attempt to improve the quality of CPR to increase the TOI before delivering shocks or administering drugs.
Prognostic factors for permanent neurological dysfunction after total aortic arch replacement with regional cerebral oxygen saturation monitoring