Hospital oxygen delivery systems provide pressures of 50-55 PSI (about 4000 cm H2O). Inappropriate administration can result in severe barotrauma. Administration of O2 by face mask in an intubated patient resulted in an inadvertent connection between the oxygen and endotracheal tubes, which caused tension pneumothorax with cardiorespiratory collapse. As several such cases have been reported, we believe O2 should be administered to intubated patients only through a T-piece connection. We call for a change in the structure of O2 delivery tubes to prevent the possibility of inadvertent connection to an endotracheal tube.