Pilot Study for the Determination of Death After Cardiac Arrest
Written on behalf of the study investigators Loretta Norton, Raechelle M. Gibson, Teneille Gofton, Carolyn Benson, Sonny Dhanani, Sam D. Shemie, Laura Hornby, Roxanne Ward, and G. Bryan Young
The article, Electroencephalographic Recordings During Withdrawal of Life-Sustaining Therapy Until 30 Minutes After Declaration of Death, from The Canadian Journal of Neurological Sciences describes a case series of four patients that were part of a larger feasibility study that asked if it was possible to monitor circulatory and neurologic function in patients during the dying process (Dhanani et al, Critical Care Medicine, 2014). Feasibility studies are meant to determine whether or not a study can be done; they are meant to be starting points, and results cannot be interpreted as conclusive or definitive. All four participants that were part of this case series were critically and terminally ill and, after a thoughtful decision by the family and medical team, underwent withdrawal of life sustaining therapies to allow natural death to occur. These patients were all declared dead by standard clinical examination by their treating physicians, who were independent from the research team. Although deceased organ donation can occur when specific criteria are met and clinical death is declared in such circumstances, none of these patients were organ donors.
Importantly, using a modified type of electroencephalography (EEG) it was shown that brain activity stopped minutes before the heart stopped beating in 3 patients. In one patient, low-frequency, sporadic EEG activity occurred after the heart stopped beating. In the article, the authors state that because this activity occurred long after the loss of circulation, this activity is likely an artefact – that is, it cannot be interpreted or trusted as accurate. EEG monitoring in patients can be subject to false readings due to environmental conditions within the intensive care unit that are not related to the patient’s brain activity. The authors conclude that the recording is a false reading and cannot be assumed to indicate that the brain is still functioning. Furthermore, the patient’s heart had stopped, there was no blood pressure, no breathing, no response to pain stimulus, and no pupil reaction. This fourth case highlighted the uncertainty about the use of this specific EEG method to monitor brain activity during the dying process. Future studies will need to monitor EEG activity with improved methods. The authors are currently carrying out a larger study with improved EEG monitoring techniques in order to further explore the pattern of loss of brain activity during the dying process.
This study did not and cannot draw conclusions about re-defining death or end-of-life. The authors are enthusiastic about the interest in media that this article has generated and look forward to sharing the results of their new study in the near future.
Electroencephalographic Recordings During Withdrawal of Life-Sustaining Therapy Until 30 Minutes After Declaration of Death is published in the Canadian Journal of Neurological Sciences and is available for a limited time for free download until April 30, 2017.