Abstract 181: A Feasability Study of Cerebral Oximetry in Cardiac Arrest

Abstract

Background: To date there has been no reliable “real time” monitoring available to determine cerebral perfusion during cardiac arrest. Whilst cerebral oximetry using near infra read spectroscopy has been utilized as a non invasive marker of cerebral perfusion during surgery, it has not been integrated into routine cardiac arrest care. Furthermore, the optimal measurement parameters that are associated with return of spontaneous circulation (ROSC) have not been determined. Objectives: To investigate the feasibility of using a commercially available cerebral oximeter (Invos 5100c, Somanetics, Troy, USA) to measure regional brain oxygen saturation(rSO2) during in-hospital cardiac arrest and determine the optimal rS02 parameters that correspond with ROSC. Methods: Cerebral oximetry was applied to 14 in-hospital cardiac arrest patients and continuous data was collected until either ROSC was achieved or CPR was terminated. The mean rSO2, median rSO2, as well as mean and median rSO2 in the last five minutes prior to ROSC or termination of CPR were measured. Results: The use of cerebral oximetry during cardiac arrest and the application of the sensor (completed in 60 ±30s) did not interfere with patient care. ROSC was achieved in 21% (n=3) of cases. Patients with ROSC had a significantly higher total mean (32±5 vs 21±7 p<0.05), median (31±5 vs 20±8 p<0.05), mean rSO2 in final 5 minutes (53±11 vs 17±5 p< 0.0001), median rS02 in final 5 minutes (47±6 vs 17±5 p< 0.0001) than non ROSC patients. In 14% (n=2) of cases, there was a failure to obtain rS02 measurements despite manufacturers recommendations being followed. This observation was only seen in the non ROSC group. Conclusion: The use of cerebral oximetry during cardiac arrest does not interfere with CPR and may be a predictor of ROSC. Although higher mean and median rS02 measurements correlate with ROSC, a rise in rS02 over a five minute period during cardiac arrest may be a better indicator of ROSC. Cerebral oximetry may potentially be used as a marker of organ perfusion as well as ROSC in cardiac arrest.