Cerebral cortical activity after withdrawal of life-sustaining measures in critically ill patients

Abstract

Establishing when cerebral cortical activity stops relative to circulatory arrest during the dying process will enhance trust in donation after circulatory determination of death. We used continuous electroencephalography and arterial blood pressure monitoring prior to withdrawal of life sustaining measures and for 30 min following circulatory arrest to explore the temporal relationship between cessation of cerebral cortical activity and circulatory arrest. Qualitative and quantitative EEG analyses were completed. Among 140 screened patients, 52 were eligible, 15 were enrolled, 11 completed the full study, and 8 (3 female, median age 68 years) were included in the analysis. Across participants, EEG activity stopped at a median of 78 (Q1 = −387, Q3 = 111) seconds before circulatory arrest. Following withdrawal of life sustaining measures there was a progressive reduction in electroencephalographic amplitude (p = .002), spectral power (p = .008), and coherence (p = .003). Prospective recording of cerebral cortical activity in imminently dying patients is feasible. Our results from this small cohort suggest that cerebral cortical activity does not persist after circulatory arrest. Confirmation of these findings in a larger multicenter study are needed to help promote stakeholder trust in donation after circulatory determination of death.

Neurologic Physiology after Removal of Therapy (NeuPaRT) study: study protocol of a multicentre, prospective, observational, pilot feasibility study of neurophysiology after withdrawal of life-sustaining measures

“…Both qualitative (visual inspection of raw EEG) and quantitative (coherence analysis) EEG analyses will be performed. 16 We will pool data across patients to calculate the mean and SD for the sample across patients. Given the difference in patient mix and approaches to WLSM between sites, we will stratify our analysis by site.…”

“…At LHSC site, we will plan to enrol an additional 1 patient/month for 18 months (total 18 patients) for EP, SSEP and BAEP studies given the unique technical abilities at this site. Similar enrolment rates were achieved in a single-centre pilot study 16. To understand feasibility challenges and modify the research plan for a larger study we will analyse study accrual, complete waveform data and success of data transfer to LHSC as outcomes regardless of the number of patients enrolled.…”

“…This is based on recruitment achieved during pilot work. 16 If we enrol <9 patients/site after 18 months, we will conclude that the larger study will not be feasible and the study approach will need to be re-evaluated. At LHSC site, we will plan to enrol an additional 1 patient/month for 18 months (total 18 patients) for EP, SSEP and BAEP studies given the unique technical abilities at this site.…”

“…Similar enrolment rates were achieved in a single-centre pilot study. 16 To understand feasibility challenges and modify the research plan for a larger study we will analyse study accrual, complete waveform data and success of data transfer to LHSC as outcomes regardless of the number of patients enrolled.…”

“…We expect to enrol 1 patient/site/month for a total of 90 patients over 18 months. This is based on recruitment achieved during pilot work 16. If we enrol <9 patients/site after 18 months, we will conclude that the larger study will not be feasible and the study approach will need to be re-evaluated.…”