Usefulness of near-infrared spectroscopy for monitoring a cerebral tissue oxygen saturation during cardio-pulmonary resuscitation (CPR)

Introduction

Near-infrared spectroscopy has been verified to be a reliable monitoring method in detecting a regional cerebral tissue oxygen saturation (rSO₂) in the field of neurosurgery, cardiovascular surgery and neonatal ICU. Cerebral tissue oxygenation is promptly and continuously monitored during resuscitation, and moreover, we can compare the efficacy among the resuscitation techniques with this method.

Materials and methods

In the 40 cardio-pulmonary arrest (CPA) cases, rSO₂ was monitored during CPR with INVOS 3100A (SEMANTICS). A traditional external CPR was started in all cases and an open chest CPR was added in 10 cases. We also measured oxygen saturation of jugular vein (SjO₂) in 14 cases at regular intervals.

Results

Serial changes of rSO₂ were 27.6 ± 10.7% at arrival, 32.7 ± 12.2% during external CPR (n = 20), 36.2 ± 5.8* during open chest CPR (n = 10), and 61.3 ± 10.0% after return of spontaneous circulation (ROSC) (n = 10) (mean ± SD), and synchronous changes were observed according to cessation and re-starting of CPR (*P < 0.02 and **P < 0.03 versus at arrival). SjO₂ was measured in 8.6 ± 3.1 min after the arrival, and initial SjO₂ during external CPR was 16.3 ± 9.8%. In some cases, increased bicarbonate concentration was observed probably due to the reflux from the infusions through central venous catheter.

Conclusions

Near-infrared spectroscopy is rapid, noninvasive, and easily applied monitoring system during resuscitation for CPA patients, and our data demonstrated to be a reliable monitoring method in detecting a cerebral tissue oxygenation. On the other hand, SjO₂ is invasive, time-consuming method, and is not always accurate because of to-and-fro flow.