Apnea testing for the diagnosis of brain death

Neurologische Universitätsklinik, Erlangen, Germany.
Acta Neurologica Scandinavica (Impact Factor: 2.44). 01/2006; 112(6):358-69. DOI: 10.1111/j.1600-0404.2005.00527.x
Source: PubMed

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.


Available from: Christoph J G Lang, May 29, 2015
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  • Turk 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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    04/2013; 8(1):1-6. DOI:10.1016/j.jtumed.2013.02.001