Flashback blood collection needle

A needle assembly comprising:

• a housing defining a housing interior, said housing comprising at least one cannula having a patient puncture tip extending from a first end of the housing and a non-patient puncture tip extending from a second end of the housing, the non-patient puncture tip and the patient puncture tip being in fluid communication with each other within the housing interior;
• and
• a porous vent positioned within the housing interior separating the housing interior into a first chamber and a second chamber, the porous vent including pores for passage of fluid therethrough from the first chamber to the second chamber, said porous vent including a blocking member to control flow of the fluid such that the fluid flows in an axial direction through the porous vent,
• wherein the housing includes a rear hub having a cylindrical portion extending therefrom and into the first chamber toward the first end of the housing to define a portion of the first chamber, said cylindrical portion forming at least a portion of the blocking member, and
• wherein the sole communication path between the housing interior and the external environment is via the patient puncture tip.