Monitoring of Cerebral Metabolism in Postcardiac Arrest Patients: A Pilot Study

For better care of postcardiac arrest patients, objective serial assessments of brain injury severity are needed. We hypothesized that monitoring of cerebral energy metabolism based on arterio-jugular (AJ) differences of metabolites will provide serial details of brain injury and information about neurologic outcomes in patients. Measurements of lactate and glucose in addition to blood gas analyses were done every 6 hours from the radial artery and jugular bulb in postcardiac arrest patients throughout targeted temperature management (TTM). Jugular bulb saturation, AJ difference of O2, and AJ difference of lactate (AJDL) were calculated and compared between the different neurologic outcome groups. Linear mixed-model analysis was done to assess AJDL based on the different phases of TTM and neurologic outcome. A total of 13 patients were included in the study (n = 4 good outcome, n = 9 poor outcome). AJDL as an indicator of cerebral metabolism was significantly different between the outcome groups and demonstrated negative values in the poor neurologic outcome group (0.06 [0.05–0.09] vs. −0.14 [−0.06 to −0.27], p < 0.01). However, there was no significant difference in AJDL between the outcome groups in the mixed effects model (p = 0.05). In addition, there were no differences between the phases of TTM in both groups (p = 0.46). AJDL was observed to be informative but was not significantly different between neurologic outcome groups throughout the different phases of TTM in our pilot study. Future studies are needed for further investigation of AJDL as an indicator of brain injury severity.