Akademik Veri Yönetim Sistemi
TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE, cilt.211, sa.2, ss.115-120, 2007 (SCI-Expanded)
Apneic oxygenation is an apnea testing method in the diagnosis of brain death. In this method, oxygen (O-2) is delivered into the trachea via an O-2 catheter (O2C). However, barotrauma may develop during O-2 insufflation into the trachea. Oxygen catheter diameters, O-2 catheter tip position in the trachea, and O-2 flow rate have been proposed as causes of barotrauma. This study was designed to highlight the airway pressure changes during apneic oxygenation in a model consisting of an anesthesia bag, which was connected to a pressure transducer and to an endotracheal tube (ETT). The pressure of the system was monitored while delivering O-2 continuously to the system through O2C of different diameters, which were placed in the ETT. Tested variables were ETT/O2C ratio, O2C tip position in ETT (proximal 1/3 of the ETT, mid point of the ETT, and distal 1/3 of the ETT) and O-2 flow rate (6, 8, and 10 L min(-1)). The increase in the airway pressure significantly correlated with O2C tip position in ETT (p = 0.017). ETT/O2C ratio smaller than 1.75 caused significantly high airway pressures (p < 0.05). The pressure was significantly higher at the flow rate of 10 L min(-1) O-2 compared with the flow rate of 6 L min(-1) O-2 (p < 0.01). Thus, ETT/O2C ratio, O2C tip position in ETT and O-2 flow rate are the important factors that determine the airway pressure in the trachea during O-2 insufflation. In conclusion, overlooked mechanical factors dangerously increase airway pressure during apnea testing.