Medical devices for blood reflux prevention and methods of use

A flush syringe assembly comprising:

• a barrel including a side wall having an inside surface defining a chamber for retaining fluid, and outside surface, an open proximal end, a distal end including a distal wall having an aperture therethrough in fluid communication with the chamber;
• an elongate plunger rod disposed within the barrel, the plunger rod comprising a distal end including a stopper slidably positioned in fluid-tight contact with the inside surface of the barrel so that distal movement of the stopper relative to the barrel pushes fluid out of the barrel;
• a cap comprising a passageway therethrough in fluid communication with the chamber, the cap including a Luer connector on a distal end and being releasably connectable to a vascular access device (VAD) and a proximal end releasably attachable to the barrel;
• and
• a valve comprising a plug positioned adjacent to the distal end of the barrel and in contact with the proximal end of the cap, the plug having a proximal face and a sidewall extending distally therefrom, the sidewall including a plurality of openings that allow fluid communication between the chamber and the VAD, the entire valve being movable by distally directed force applied by the stopper from a proximal open position that permits fluid flow between the chamber and the VAD through the plurality of openings and a distal closed position that prevents fluid communication between a blood vessel and the VAD,
• wherein the proximal face of the valve comprises a plurality of openings allowing fluid communication between the chamber and the cap, and a valve stem extends distally from a center of the valve, the valve stem having a proximal diameter and a distal diameter greater than the proximal diameter and the cap further comprises a valve seat that forms a fluid-tight seal when the valve stem is in complete contact therewith.

A flush syringe assembly comprising:

• a barrel including a side wall having an inside surface defining a chamber for retaining fluid, and outside surface, an open proximal end, a distal end including a distal wall having an aperture therethrough in fluid communication with the chamber;
• an elongate plunger rod disposed within the barrel, the plunger rod comprising a distal end including a stopper slidably positioned in fluid-tight contact with the inside surface of the barrel so that distal movement of the stopper relative to the barrel pushes fluid out of the barrel;
• a cap comprising a passageway therethrough in fluid communication with the chamber, the cap including a Luer connector on a distal end and being releasably connectable to a vascular access device (VAD) and a proximal end releasably attachable to the barrel;
• a valve comprising a plug positioned adjacent to the distal end of the barrel and in contact with the proximal end of the cap, the plug having a proximal face and a sidewall extending distally therefrom, the sidewall including a plurality of openings that allow fluid communication between the chamber and the VAD, the entire valve being movable by distally directed force applied by the stopper from a proximal open position that permits fluid flow between the chamber and the VAD through the plurality of openings and a distal closed position that prevents fluid communication between a blood vessel and the VAD;
• a valve stem extending distally from a center of the valve, the valve stem having a proximal end with a proximal diameter and a distal end with a distal diameter greater than the proximal diameter;
• and
• the cap further comprises a valve seat within the passageway biased radially inwardly, the valve seat having a proximal face and a distal face and the distal end of the valve stem is in an initial position in contact with the proximal face of the valve seat forming a seal against distal fluid movement and the plurality of openings in the valve are unobstructed.