Arguments Opposing the Requirement to Demonstrate Absence of Brain Circulation to Determine Death by Neurologic Criteria

Abstract

There is robust international consensus that death by neurologic criteria is the “complete and permanent loss of brain function as defined by an unresponsive coma with loss of capacity for consciousness, brainstem reflexes, and the ability to breath independently” (World Brain Death Project 2020). The determination of death by neurologic criteria is therefore based on a rigorous and comprehensive clinical neurologic evaluation. In certain cases, a valid neurologic examination cannot be made, and it is necessary to rely on useful, but imperfect, paraclinical data obtained from ancillary testing. Some experts hold the position that ancillary testing should be mandatory for determination of death by neurologic criteria. Specifically, some propose that demonstration of absent brain circulation should be a requirement for the determination of death by neurologic criteria. In this chapter, we argue that the determination of death by neurologic criteria does not require the demonstration of absent brain circulation. Our arguments are based on three main points. First, we contend that the evaluation for death by neurologic criteria is focused on the clinical demonstration of permanent loss of brainstem function, and it is not relevant to add surrogates of function, such as circulation and perfusion, to the determination process. Further, we argue that brain circulation is not an ideal surrogate for brainstem function. Finally, we discuss that brain circulation ancillary tests are of variable diagnostic accuracy, and are not properly validated for determination of death by neurologic criteria.