Apnea testing for the diagnosis of brain death
ABSTRACT A review is given on various methods, preconditions and pitfalls of apnea testing for the diagnosis of brain death.
An extensive medical data base search was implemented by information gathered from books and our own experience with more than 2000 apnea tests.
While testing for apnea (AT) is considered indispensable worldwide, recommendations and handling differ. Rather than relying on elapsed time, a specific target value for the partial arterial pressure of carbon dioxide (PaCO2) should be aimed at being the maximum physiological stimulus for respiration. Methodological points are elaborated upon in detail for apneic oxygenation and hypoventilation.
AT is an indispensable element of diagnosing brain death. Although with proper handling and adequate precautions AT is safe, it should be performed as a last resort. An international agreement on target values for the PaCO2 is desirable.
Full-textDOI: · Available from: Christoph J G Lang, May 29, 2015
Article: Çocuklarda beyin ölümüTurk Pediatri Arsivi 06/2011; 46(2):99-103. DOI:10.4274/tpa.46.54 · 0.06 Impact Factor
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ABSTRACT: BackgroundThe apnea test (AT) is essential to confirming the diagnosis of brain death, but critical complications can occur if the AT is maintained over a long period. To minimize the AT period, we used end-tidal carbon dioxide (ETCO2) monitoring because ETCO2 is closely correlated with partial pressure of arterial carbon dioxide (PaCO2). The aim of the present study is to evaluate the usefulness of ETCO2 monitoring during apnea testing.MethodsWe reviewed 61 patients who were pronounced brain dead at our hospital from July 2009 to December 2012. The subjects were divided into two groups: the N-group, in which capnography was not used, and the C-group, in which capnography was used to monitor ETCO2. In the C-group, whenever arterial blood was sampled, the PaCO2 - ETCO2 gradients were calculated and the ventilator setting adjusted to maintain normocapnia prior to apnea testing.ResultsTwenty-eight subjects in the N-group and twenty-nine subjects in the C-group were included. The gender ratio, age, and cause of brain death were not different between the two groups. Prior to the AT, the normocapnia ratio was higher in the C-group than in the N-group. During the AT, the total test period was shorter in the C-group. Moreover, systolic blood pressure increased in the C-group and decreased in the N-group during apnea testing.ConclusionsETCO2 monitoring during AT allows the PaCO2 level to be predicted, which reduces the duration of the test and stabilizes systolic blood pressure. Thus, with ETCO2 monitoring, the AT can be fast and safe.Korean journal of anesthesiology 09/2014; 67(3):186-92. DOI:10.4097/kjae.2014.67.3.186
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ABSTRACT: Objective This paper identified ethical issues relating to brain death and analyzed them according to the purposes of the Law, maqasid al shari’at, and principles of the law, qawa’id al fiqh, to reach conclusions of practical importance. Methods Issues arising in brain death were selected from articles retrieved from PUBMED over a 10-year period. Practical and conceptual issues identified in the articles were analyzed using maqasid al shari’atand qawa’id al fiqh. Results Early determination of death by use of brain death criteria was motivated by the need to harvest transplantation organs earlier, to save intensive care resources by earlier cessation of life support, and to obtain tissues for research before deterioration. These motives would violate the principle of intention which requires that actions be judged by underlying intentions and that the end does not justify the means. In this case the nobility of the ends and their public interest were overriding considerations. The requirements, by the principle of certainty, of evidence-based proof of death were partially fulfilled by brain death criteria, tests, and examinations. The principle of custom was partially fulfilled because there was no universal consensus on criteria of brain death; the criteria varied by country, by institution, and over time. Conclusions and recommendations Brain stem death, determined by clinical examination with or without instrumental confirmation, should remain the mainstay of death definition. Legal rulings on brain death should be reviewed every 3 years to take into consideration new developments in medical knowledge and technology.04/2013; 8(1):1-6. DOI:10.1016/j.jtumed.2013.02.001