In the final hours, days, or even weeks before passing away, many patients slip into an unresponsive state where they are unable to communicate with their caretakers. Because such patients are unable to communicate, their caretakers must rely on indirect information to judge the patient’s state of consciousness. Because the subjective state of the patient is central to the clinical decision making, any reliable information indicative of retained capacity for consciousness is essential for providing appropriate treatment for the dying.
While responsiveness and consciousness normally go hand in hand, decades of work in the field of consciousness studies has given us good reason to believe that many non-communicative patients in unresponsive states retain consciousness covertly. Thus, they may retain a capacity for both positive and negative subjective experience, even though they are unable to communicate this to people around them. The development, testing, and application of objective measures of brain activity has been central to the progress in this field, and has shown promise for stratifying patients previously assumed to be unconscious into groups more or less likely to have retained capacity for covert conscious experiences.
In our project, we aim to apply the latest knowledge from the field of consciousness science to study the presence and prevalence of consciousness in non-communicative dying patients. Using quantitative and qualitative methods, we aim to develop and test measures based on ongoing brain activity to investigate whether, when, and how often, dying patients may still have the capacity for conscious experiences. Our team of doctors, ethicists, and experts on brain monitoring will work in close collaboration with clinical caretakers, patients, and their next-of-kin, to understand how the knowledge and tools developed in our project can best be applied to the clinical practice, to serve the interests of the dying.
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 cross-disciplinary 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.