External validation of prediction models for time to death in potential donors after circulatory death

Predicting time to death in controlled donation after circulatory death (cDCD) donors following withdrawal of life-sustaining treatment (WLST) is important but poses a major challenge. The aim of this study is to determine factors predicting time to circulatory death within 60minutes after WSLT and validate previously developed prediction models. In a single-center retrospective study, we used the data of 92 potential cDCD donors. Multivariable regression analysis demonstrated that absent cough-, corneal reflex, lower morphine dosage, and midazolam use were significantly associated with death within 60minutes (area under the curve [AUC] 0.89; 95% confidenence interval [CI] 0.87-0.91). External validation of the logistic regression models of de Groot etal (AUC 0.86; 95% CI 0.77-0.95), Wind etal (AUC 0.62; 95% CI 0.49-0.76), Davila etal (AUC 0.80; 95% CI 0.708-0.901) and the Cox regression model by Suntharalingam etal (Harrell's c-index 0.63), exhibited good discrimination and could fairly identify which patients died within 60minutes. Previous prediction models did not incorporate the process of WLST. We believe that future studies should also include the process of WLST as an important predictor. This study externally validates previous predictive models for time to death in controlled donation after circulatory death donors and identifies that absence of brainstem reflexes, persistent ventilatory failure, and aspects of withdrawal of life-support treatment are predictors for death within 60 minutes