Diffuse leptomeningeal carcinomatosis mimicking brain death

Determination of Brain Death/Death by Neurologic Criteria: The World Brain Death Project

IMPORTANCE

There are inconsistencies in concept, criteria, practice, and documentation of brain death/death by neurologic criteria (BD/DNC) both internationally and within countries.

OBJECTIVE

To formulate a consensus statement of recommendations on determination of BD/DNC based on review of the literature and expert opinion of a large multidisciplinary, international panel.

PROCESS

Relevant international professional societies were recruited to develop recommendations regarding determination of BD/DNC. Literature searches of the Cochrane, Embase, and MEDLINE databases included January 1, 1992, through April 2020 identified pertinent articles for review. Because of the lack of high-quality data from randomized clinical trials or large observational studies, recommendations were formulated based on consensus of contributors and medical societies that represented relevant disciplines, including critical care, neurology, and neurosurgery.

EVIDENCE SYNTHESIS

Based on review of the literature and consensus from a large multidisciplinary, international panel, minimum clinical criteria needed to determine BD/DNC in various circumstances were developed.

RECOMMENDATIONS

Prior to evaluating a patient for BD/DNC, the patient should have an established neurologic diagnosis that can lead to the complete and irreversible loss of all brain function, and conditions that may confound the clinical examination and diseases that may mimic BD/DNC should be excluded. Determination of BD/DNC can be done with a clinical examination that demonstrates coma, brainstem areflexia, and apnea. This is seen when (1) there is no evidence of arousal or awareness to maximal external stimulation, including noxious visual, auditory, and tactile stimulation; (2) pupils are fixed in a midsize or dilated position and are nonreactive to light; (3) corneal, oculocephalic, and oculovestibular reflexes are absent; (4) there is no facial movement to noxious stimulation; (5) the gag reflex is absent to bilateral posterior pharyngeal stimulation; (6) the cough reflex is absent to deep tracheal suctioning; (7) there is no brain-mediated motor response to noxious stimulation of the limbs; and (8) spontaneous respirations are not observed when apnea test targets reach pH <7.30 and Paco2 ≥60 mm Hg. If the clinical examination cannot be completed, ancillary testing may be considered with blood flow studies or electrophysiologic testing. Special consideration is needed for children, for persons receiving extracorporeal membrane oxygenation, and for those receiving therapeutic hypothermia, as well as for factors such as religious, societal, and cultural perspectives; legal requirements; and resource availability.

CONCLUSIONS AND RELEVANCE

This report provides recommendations for the minimum clinical standards for determination of brain death/death by neurologic criteria in adults and children with clear guidance for various clinical circumstances. The recommendations have widespread international society endorsement and can serve to guide professional societies and countries in the revision or development of protocols and procedures for determination of brain death/death by neurologic criteria, leading to greater consistency within and between countries.

What to exclude when brain death is suspected

BACKGROUND

With advances in critical care and organ donation, diagnosis of brain death is gaining importance. We aimed to assess potential brain death confounders from the literature, elucidating clinical presentation and diagnostic approaches in these cases.

METHODS

PubMed and Embase were screened using 37 predefined search terms to identify suitable articles reporting cases, case series, or cohort studies in adults.

RESULTS

Out of 4769 articles, 40 case reports or case series describing 45 patients with 19 critical conditions were identified. Mortality was 11% and full recovery 33%. Intoxications (42%; mainly anti-seizure drugs and baclofen) and polyneuritis (37%) were most frequent. Brainstem reflex tests were reported in 96%, apnoea test in 16% and ancillary tests in all but one patient. Full recovery mainly occurred with intoxications. Quality of evidence regarding frequency of confounders is very low and risk of bias high.

CONCLUSIONS

Brain death confounders are infrequently reported and formal studies are lacking. Mainly younger patients with polyneuritis and intoxications are described. As outcome, especially in the latter, is often favourable, high awareness and strict adherence to guidelines is crucial. The importance of identifying pathologies compatible with extensive and irreversible brain damage before proceeding to diagnostic tests should be emphasized.