Monitoring the Relationship Between Changes in Cerebral Oxygenation and Electroencephalography Patterns During Cardiopulmonary Resuscitation: A Feasibility Study

Objectives: To date, no studies have examined real-time electroencephalography and cerebral oximetry monitoring during cardiopulmonary resuscitation as markers of the magnitude of global ischemia. We therefore sought to assess the feasibility of combining cerebral oximetry and electroencephalography in patients undergoing cardiopulmonary resuscitation and further to evaluate the electroencephalography patterns during cardiopulmonary resuscitation and their relationship with cerebral oxygenation as measured by cerebral oximetry. Design: Extended case series of in-hospital and out-of-hospital cardiac arrest subjects. Setting: Tertiary Medical Center. Patients: Inclusion criteria: Convenience sample of 16 patients undergoing cardiopulmonary resuscitation during working hours between March 2014 and March 2015, greater than or equal to 18 years. A portable electroencephalography (Legacy; SedLine, Masimo, Irvine, CA) and cerebral oximetry (Equanox 7600; Nonin Medical, Plymouth, MN) system was used to measure cerebral resuscitation quality. Interventions: Real-time regional cerebral oxygen saturation and electroencephalography readings were observed during cardiopulmonary resuscitation. The regional cerebral oxygen saturation values and electroencephalography patterns were not used to manage patients by clinical staff. Measurements and Main Results: In total, 428 electroencephalography images from 16 subjects were gathered; 40.7% (n = 174/428) were artifactual, therefore 59.3% (n = 254/428) were interpretable. All 16 subjects had interpretable images. Interpretable versus noninterpretable images were not related to a function of time or duration of cardiopulmonary resuscitation but to artifacts that were introduced to the raw data such as diaphoresis, muscle movement, or electrical interference. Interpretable data were able to be obtained immediately after application of the electrode strip. Seven distinct electroencephalography patterns were identified. Voltage suppression was commonest and seen during 78% of overall cardiopulmonary resuscitation time and in 15 of 16 subjects at some point during their cardiopulmonary resuscitation. Other observed patterns and their relative prevalence in relation to overall cardiopulmonary resuscitation time were theta background activity 8%, delta background activity 5%, bi frontotemporal periodic discharge 4%, burst suppression 2%, spike and wave 2%, and rhythmic delta activity 1%. Eight of 16 subjects had greater than one interpretable pattern. At regional cerebral oxygen saturation levels less than or equal to 19%, the observed electroencephalography pattern was exclusively voltage suppression. Delta background activity was only observed at regional cerebral oxygen saturation levels greater than 40%. The remaining patterns were observed throughout regional cerebral oxygen saturation categories above a threshold of 20%. Conclusions: Real-time monitoring of cerebral oxygenation and function during cardiac arrest resuscitation is feasible. Although voltage suppression is the commonest electroencephalography pattern, other distinct patterns exist that may correlate with the quality of cerebral resuscitation and oxygen delivery. This work was performed at Stony Brook University Hospital. The research protocol was approved by the Stony Brook University Hospital Institutional Review Board prior to the start of recruitment and data collection. All authors either had access to all the deidentified data or had the opportunity to review all aggregate data during analysis. The lead author affirm that the article is an honest, accurate, and transparent account of the study results being reported and that no important aspects of the study have been omitted and that any discrepancies from the study as planned have been explained. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website (http://ift.tt/29S62lw). Supported, in part, with funds provided by the American Heart Association Clinical Research Program, New York State Empire Clinical Research Investigator Program award, the BIAL Foundation and the Templeton Foundation (via a subaward from the University of California at Riverside). The researchers worked independent of the funding bodies. The funding sponsors also did not participate in study design, analysis and interpretation of results or the writing of the article. The cerebral oximetry equipment was provided by Nonin Medical; however, the company had no other role in the study. The electroencephalography monitor was provided by Massimo; however, the company had no other role in the study. Dr. Reagan disclosed that the study was supported with funds provided by the American Heart Association Clinical Research Program, New York State Empire Clinical Research Investigator Program award, the BIAL Foundation and the Templeton Foundation (via a subaward from the University of California at Riverside), and she disclosed that the cerebral oximetry equipment was provided by Nonin Medical. Drs. Reagan and Parnia disclosed that they received a loaner equipment Massimo legacy electroencephalography unit for the study. Dr. Nguyen's institution received funding from the American Heart Association. Dr. Parnia received support for article research from the American Heart Association. The remaining authors have disclosed that they do not have any potential conflicts of interest. Address requests for reprints to: Elizabeth Reagan, MD, Department of Medicine, State University of New York at Stony Brook, Stony Brook Medical Center, T17-040 Health Sciences Center, Stony Brook, NY. E-mail: Elizabeth.reagan@stonybrookmedicine.edu Copyright © by 2018 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

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