Efficacy of a T-piece system and a continuous positive airway pressure system for apnea testing in the diagnosis of brain death.
OBJECTIVE
To prospectively compare three methods of apnea testing for the confirmation of brain death.


METHODS
Prospective, randomized, crossover study.


METHODS
Intensive care unit of a tertiary care university hospital.


METHODS
Twenty adult patients requiring apnea testing for confirmation of brain death.


METHODS
Ten minute apnea testing was repeated in random order for every patient with the three oxygenation systems: oxygen catheter inserted through the endotracheal tube (oxygen 6 L/min), T-piece system (oxygen 12 L/min), and continuous positive airway pressure (CPAP) system 10 cm H2O (oxygen 12 L/min).


RESULTS
Arterial blood was drawn at 0, 2, 5, and 10 mins of each test. Compared with baseline, Paco2 increased by 30.6 +/- 7.4, 30.0 +/- 7.3 and 30.2 +/- 7.5 mm Hg during the apnea period (p = .96), reaching 73.3 +/- 8.3, 71.6 +/- 11.1, and 72.7 +/- 9.0 mm Hg at the end of the apnea test (p = .73) for the oxygen catheter, the T-piece, and the CPAP, respectively. Pao2 decreased less with the CPAP compared with the oxygen catheter or the T-piece (-22.4 +/- 76, -99.1 +/- 158, and -91.6 +/- 133 mm Hg, respectively, p < .01). In two patients, apnea testing could not be completed with the oxygen catheter and the T-piece because of desaturation, although it could be completed with the CPAP.


CONCLUSIONS
The T-piece and the CPAP systems are effective alternatives to the standard oxygen catheter technique for apnea testing. Oxygenation was best maintained with the CPAP system, which can be useful in some patients.
Lévesque
Simon
S
Department of Anesthesiology, Centre Hospitalier Affilié Universitaire de Québec, Université Laval, Quebec City, Quebec, Canada.
Lessard
Martin R
MR
Nicole
Pierre C
PC
Langevin
Stéphan
S
LeBlanc
François
F
Lauzier
François
F
Brochu
Jacques G
JG
D000328:Adult; D000368:Aged; D001049:Apnea / Q000097:blood*; D001926:Brain Death / Q000175:diagnosis*; D002245:Carbon Dioxide / Q000097:blood; D002408:Catheters, Indwelling; D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy / Q000379:methods; D011446:Prospective Studies
D002245:Carbon Dioxide; D010100:Oxygen