title: Apnea testing for the diagnosis of brain death.
abstract: OBJECTIVE
  A review is given on various methods, preconditions and pitfalls of apnea testing for the diagnosis of brain death.
  
  
  METHODS
  An extensive medical data base search was implemented by information gathered from books and our own experience with more than 2000 apnea tests.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Neurologische Universitätsklinik, Erlangen, Germany. christoph.lang@neuro.imed.uni-erlangen.de
authors.forename: C J G
authors.initials: CJ
authors.lastname: Lang
authors.forename: J G
authors.initials: JG
authors.lastname: Heckmann
mesh_terms: D001785:Blood Gas Monitoring, Transcutaneous / Q000295:instrumentation*; D001926:Brain Death / Q000175:diagnosis* / Q000503:physiopathology; D001933:Brain Stem / Q000503:physiopathology; D002628:Chemoreceptor Cells / Q000503:physiopathology; D006801:Humans; D008526:Medulla Oblongata / Q000503:physiopathology; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation; D012121:Respiration, Artificial; D012125:Respiratory Center / Q000503:physiopathology; D012680:Sensitivity and Specificity