Background: At present, organ donation after brain death (DBD) is the main source of available transplanted organs, and potential DBD donors mainly come from neurocritical patients. Brainstem function failure is the trend of progression to brain death in neurocritical patients. Early identification of this trend is beneficial for identifying potential DBD donors. Objective: The aim of this study is to construct a Nomogram model for predicting brainstem functional failure in neurocritical patients within 72 hours after brain injury, for early identification of potential DBD donors. From June 1, 2022 to May 31, 2023, retrospective inclusion of potential DBD donors (neurological critically ill patients) admitted to our center, mainly with traumatic brain injury and spontaneous cerebral hemorrhage, recording relevant parameters of brain injury for constructing a training set. From June 1, 2023 to May 31, 2024, Prospective inclusion of critically ill neurological patients admitted to our center, mainly with traumatic brain injury and spontaneous cerebral hemorrhage, dynamically recording and evaluating relevant parameters of brain injury for constructing a validation set. Using the occurrence of brainstem function failure within 72 hours after brain injury as a time point of interest and grouping factor, univariate and multivariate analysis were conducted to identify factors related to brainstem function failure. Then, a Nomogarm prediction model was constructed, and finally, the Nomogarm prediction model was validated in the validation set.
Result: According to the inclusion criteria, a total of 129 patients were included in the study; 66 cases entered the training set and 63 cases entered the validation set. In the training set, univariate and multivariate analyses showed that midline structural shift more than 5mm (OR=3.96, 95% 1.77-18.31), disappearance of the Cisterna ambiens on head CT (OR=4.79, 95% 1.41-17.14), casting of the ventricles on head CT (OR=3.17, 95% 1.56-14.55), absent of cough reflex (OR=4.12, 95% 1.32-14.19), and blood Na+<125mmol/L (OR=2.96, 95% 1.61-14.56) were the related factors to brainstem function failure within 72 hours after brain injury in neurocritical patients. Then, a Nomogram prediction model was constructed based on these related factors. In the training and validation sets, the predictive C-index for brainstem failure within 72 hours after brain injury in neurocritical patients was 0.82 (95% CI 0.76-0.86) and 0.81 (95% CI 0.77-0.85), respectively. Further statistical analysis shows that scores of 140, 160, and 170 are the risk cut-off points, with the probability of brainstem function failure within 72 hours being 33.6%, 68.6%, and 96.4%, respectively, for scores of 140, 160, and 170.
Conclusion: The Nomogram model constructed based on factors related to brain injury assessment can predict the occurrence of brainstem functional failure in neurocritical patients and can be used for early identification of potential DBD donors. The results need further external data validation.