It is time to abandon apneic-oxygenation testing for brain death

Abstract

It is time to abandon apneic-oxygenation testing for brain death For decades the apneic-oxygenation test has been used as a key component of clinical testing to determine if a potential organ donor has sustained irreversible loss of the ability to breathe spontaneously in the context of a hypercarbic challenge. When no respiratory effort is observed in association with irreversible unresponsive coma due to severe brain injury the victim is concluded to be "brain dead" and is an eligible organ donor. However, there is a growing clinical and legal opposition to performance of this test. The apneic-oxygenation test is essential to satisfy the requirements of the second section of Uniform Determination of Death Act (UDDA), proposed in 1981, to defi ne death in which: An individual who has sustained either 1) irreversible cessation of circulatory and respiratory functions or 2) irreversible cessation of all functions of the entire brain, including the brainstem, is dead. A determination of death must be made in accordance with accepted medical standards." The UDDA in this form or slight variations has been adopted by most States and has been adopted in other countries, again with slight variations such as that in section 41 of the Human Tissue Act 1982 in the State of Victoria in Australia: "For the purposes of the law of Victoria, a person has died when there has occurred-(a) irreversible cessation of circulation of blood in the body of the person; or (b) irreversible cessation of all function of the brain of the person." Such legislation does not stipulate how brain death should be determined but the apneic-oxygenation test is an integral part of death determination. This test is conducted only when irreversible unresponsive coma is present and all confounding factors such as depressive medication, hypothermia, metabolic and electrolytic disturbances have been excluded. The test cannot be used if another injury such as high cervical cord damage prevents a neuromuscular response to hypercarbia, and is performed only when other brainstem refl exes are absent. Medical opposition to the apneic-oxygenation test Some organ procurement guidelines, for example those of