Brain Death in Intensive Care Units: Problems, Differences in Methods of Diagnosis, and Donor Care

The Role of S100b Protein Biomarker in Brain Death: A Literature Review

Brain death (BD) represents the irreversible loss of all brain functions, including the brainstem, and is equivalent to clinical death established by neurological criteria. However, clinical diagnosis, mainly based on the absence of primary reflexes post-acute brain injury, remains a challenge in hospital settings. The S100 calcium-binding protein beta (S100b) is used to monitor brain injuries, as recommended by neurotrauma care guidelines in some countries. Its levels are associated with severity and mortality, particularly after traumatic brain injury (TBI) and cerebral hemorrhage. The evaluation of S100b levels in investigating brain death is promising; however, aspects such as cutoff values remain to be elucidated. This paper reviews the literature on the use of S100b as a biomarker in diagnosing brain death. It is noteworthy that there is still no defined cutoff for S100b levels in confirming brain death. Additionally, when considering the use of S100b in emergency situations, a point-of-care methodology should be established to support clinical decision-making quickly and easily in the early identification of patients who are more likely to progress to brain death. In this context, S100b levels may assist in establishing the diagnosis of brain death, complementing existing clinical evidence. This, in turn, can optimize and qualify the organ donation process, reducing costs with ineffective therapies and minimizing the suffering of the families involved.

Approach of the Clinicians Practicing in Intensive Care Units to Brain Death Diagnosis and Training Expectations in Turkey: A Web-Based Survey

BACKGROUND

For health professionals, recognizing and diagnosing brain death is vital for the development of organ transplantation. However, cadaveric organ donation rates remain insufficient, and this problem has become one of the most serious obstacles in the treatment of end-organ failure.

OBJECTIVES

This study examines the attitude and knowledge level of clinicians who practice in intensive care units (ICUs) concerning the determination of brain death and describes the hindrances in diagnosing brain death.

MATERIALS AND METHODS

A survey study was designed with 26 questions, including questions regarding the determination of characteristics of respondents' trainings, practicing preferences, and their knowledge and approach toward brain death diagnosis. Clinicians practicing in ICUs in Turkey were invited to the survey.

RESULTS

A total of 244 surveys were fully completed. Physicians working at the university hospitals or university-affiliated hospitals answered the basic knowledge questions about brain death more accurately (P < .001). Also, physicians employed in university or university-affiliated hospitals feel more capable in diagnosing brain death (P = .002) and are more willing to receive education on the brain death issue (P < .001).

CONCLUSION

There is a gap separating the practices suggested in guidelines and the daily practice of ICU clinicians working in state hospitals or private institutions. Academic organizations producing and leading the education curricula may assist in informing ICU clinicians who should be trained.

Reliability of the Telemedicine Examination in the Neurologic Diagnosis of Death

Objective

To determine whether telemedicine technology can be used to reliably determine the neurologic diagnosis of death (NDD) in patients with catastrophic brain injury (CBI).

Methods

We included a convenience sample of patients with CBI at a single academic medical center from November 2016 through June 2018. We simultaneously performed brain death evaluation at the bedside and remotely via telemedicine. Remote examiners were neurointensivists who were experienced and knowledgeable in the NDD. In addition to standard clinical examination, we used quantitative pupillometry to evaluate pupil size and reactivity. We determined the proportion of agreement for each NDD examination element and the overall diagnosis of brain death between bedside and remote examiners.

Results

Twenty-nine patients with mean age 46 ± 18 years underwent 30 paired NDD examinations. Twenty-eight (97%) patients met the NDD criteria and were pronounced dead. One patient did not meet the NDD criteria and died after withdrawal of life support. With the exception of qualitative assessment of pupillary reactivity, we observed excellent agreement (97%-100% across NDD examination elements) between bedside and remote examiners and 97% agreement on the overall diagnosis of brain death. Unlike qualitative pupillary assessment, quantitative pupillometry was consistently interpretable by remote examiners.

Conclusions

Our results suggest that remote telemedicine technology can be used to verify the findings of bedside examiners performing NDD examinations when a pupillometer is used to assess pupillary reactivity. When performed by neurocritical care experts, the telemedicine NDD examination has potential to facilitate timely and accurate certification of brain death in patients with CBI.

Classification of Evidence

This study provides Class IV evidence on the concordance of neurologic diagnosis of death by telemedicine and bedside examiners.