Neuroimaging Augments DCD-N Score in Predicting Time from Withdrawal of Life-Sustaining Measures to Death Among Potential Organ Donors

Background: Controlled donation after circulatory determination of death (DCD) is feasible only if circulatory arrest occurs soon after withdrawal of life-sustaining measures (WLSM). When organ recovery cannot proceed because this time interval is too long, there are potential negative implications, including perceptions of "secondary loss" for patients' families and significant resource consumption. The DCD-N score is a validated clinical tool for predicting rapid death following WLSM. We hypothesized that neuroimaging evidence of effaced perimesencephalic cisterns improves prediction of time to death compared with the DCD-N score alone.

Methods: In a retrospective population-based cohort study, DCD-N scores were prospectively determined in patients for whom consent for DCD had been obtained. Perimesencephalic cisterns on last available neuroimaging were assessed in duplicate and classified as normal, partially effaced, or completely effaced. Multivariable logistic regression assessed the capacity of DCD-N score and effaced cisterns to predict death within 1, 2, or 3 h of WLSM.

Results: Of 164 consecutive patients, 49 (30%) progressed to death by neurologic criteria and were excluded. Of the remaining 115 patients, 81 (70%) died within 2 h of WLSM. When perimesencephalic cisterns were patent, this occurred in 48% of patients, compared with 88% and 93%, respectively, of patients with partially and completely effaced cisterns (p < 0.0001). In multivariable analysis, the odds ratio for prediction of death within 2 h was 7.2 (2.8-18.3) for each incremental DCD-N score and 15.4 (4.1-58.1) for the presence of either partially or completely effaced cisterns (c = 0.92 vs. 0.75-0.84 for univariate models). Results were comparable for prediction of death within 1 or 3 h. With patent cisterns, median time to death was 132.5 (21-420) minutes, compared with 23.5 (16-32) and 22 (19-30) minutes, respectively, with partially and completely effaced cisterns (p = 0.0002).

Conclusions: Cerebral edema with effaced perimesencephalic cisterns predicts rapid death following WLSM in potential DCD organ donors and improves on performance of the DCD-N score alone. Although originally validated for the prediction of death within 1 h, the DCD-N score remains predictive up to 3 h following WLSM.