A blood collection device includes a needle hub with a flashback chamber and a
vent plug covering the flashback chamber. The vent plug permits a flow of air across
the vent plug but prevents a flow of liquid across the vent plug. An intravenous
cannula is mounted to the hub and extends into the flashback chamber. A non-patient
cannula is mounted to the hub and also extends into communication with the flashback
chamber. A passive shielding device is mounted to the hub and can be moved from
a proximal position where the intravenous cannula is exposed to a distal position
where the intravenous cannula is partly shielded. The flashback chamber can be
observed to provide an early indication of venous access. A fluid collection tube
then can be placed in communication with the non-patient needle and can simultaneously
trigger movement of the safety shield.
