American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

A positive apnea test is indeed a necessary diagnostic criterion for declaring brain death prior to organ donation. This test is conducted to assess the presence of respiratory drive when carbon dioxide levels in the blood rise. In a brain-dead individual, the brainstem function is absent, meaning that there will be no respiratory effort even when the carbon dioxide levels are significantly elevated, indicating the loss of involuntary breathing.

This apnea test is crucial because it helps confirm that the brain has ceased all functions, which is a fundamental requirement for diagnosing brain death. Successful execution of this test reinforces the medical determination that the patient meets the critical criteria for brain death, helping ensure that the individual is truly nonviable and supports the decision for organ donation.

Other options refer to aspects of evaluation and diagnosis but do not serve as definitive criteria for confirming brain death. For instance, while an MRI might show damage indicative of severe brain injury, it is not routinely performed specifically for declaring brain death. Similarly, neurologic consultation and EEG monitoring can provide valuable information but do not fulfill the specific requirement that is satisfied by a positive apnea test in the context of brain death determination.