A flush syringe assembly comprising: a barrel including a side wall having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end including a distal wall with a tip extending distally therefrom having a passageway therethrough in fluid communication with said chamber ; and an elongate plunger rod disposed within the barrel , ; characterized in that the plunger rod having one or more protrusions disposed on an outside surface of the plunger rod ; a pulsing element disposed on an open proximal end of the barrel , the pulsing element includes an upper portion and a lower portion that join to attach to the open proximal end of the barrel , the upper portion comprises a partial opening and the lower portion comprises a partial opening , the partial opening of the upper portion and the partial opening of the lower portion form a full opening configured to receive the plunger rod and surrounding the open proximal end of the barrel , the full opening having a smaller cross-sectional width portion when measured from a bottom end of the upper portion to a bottom end of the lower portion ; the smaller cross-sectional portion is less than the cross-sectional width of the plunger rod when measured at the one or more protrusions disposed on an outside surface of the plunger rod , the full opening having a greater cross-sectional width portion when measured from a joint of the upper portion and the bottom portion that is greater than the cross-sectional width of the plunger rod when measured at the one or more protrusions disposed on an outside surface of the plunger rod . a barrel including a side wall having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end including a distal wall with a tip extending distally therefrom having a passageway therethrough in fluid communication with said chamber ; and an elongate plunger rod disposed within the barrel , ; characterized in that the plunger rod having one or more protrusions disposed on an outside surface of the plunger rod ; a pulsing element disposed on an open proximal end of the barrel , the pulsing element includes an upper portion and a lower portion that join to attach to the open proximal end of the barrel , the upper portion comprises a partial opening and the lower portion comprises a partial opening , the partial opening of the upper portion and the partial opening of the lower portion form a full opening configured to receive the plunger rod and surrounding the open proximal end of the barrel , the full opening having a smaller cross-sectional width portion when measured from a bottom end of the upper portion to a bottom end of the lower portion ; the smaller cross-sectional portion is less than the cross-sectional width of the plunger rod when measured at the one or more protrusions disposed on an outside surface of the plunger rod , the full opening having a greater cross-sectional width portion when measured from a joint of the upper portion and the bottom portion that is greater than the cross-sectional width of the plunger rod when measured at the one or more protrusions disposed on an outside surface of the plunger rod . <EOS>