Assessing the presence of covert consciousness in unresponsive dying patients. A translational research project.

In the terminal stage before death, patients often become partially or completely unresponsive and unable to communicate coherently with caretakers. Although unresponsiveness is often associated with unconsciousness, recent research has shown that a surprisingly high proportion of unresponsive patients retain consciousness in some patient populations (e.g. as much as 43% of unresponsive patients suffering from disorders of consciousness have been shown to be misclassified as unconscious). This may also be true for dying patients, meaning that they may suffer from symptoms such as pain, thirst, and anxiety, that are not recognized and treated. However, this potential issue has been largely ignored, and would benefit from being addressed using state-of-the art methods. Our crossdisciplinary team of experts on brain-based measures of consciousness, clinical palliative care, and medical ethics aims to contribute to solving this issue. Specifically, we will assess how the best brain-based measures of consciousness can be used in palliative care, to understand when and how often unresponsive dying patients retain consciousness covertly. In phase 1 of our project, we will select, adapt, and test theoretically and empirically sound candidate measures that are likely to be useful for detecting consciousness in unresponsive patients. These measures will be evaluated for use in the palliative care settings in control experiments with healthy volunteers and patients. In phase 2, we will apply the most promising candidate measures in unresponsive, dying patients, and evaluate their clinical value and apparent capacity to detect covert consciousness. Importantly, the project will be conducted in close collaboration with patients, their next of kin, interest organizations, and clinical staff, to ensure our tools can be used in ways that improve care for the dying and maintain dignity in a difficult time, rather than just adding to the interventional load at the end of life.