Patent ID: 7935103

Claim:
A method of flushing a catheter comprising the steps of: (a) providing a prefilled flush syringe assembly, said assembly including a syringe barrel having an elongated body defining a chamber for retaining fluid, an open proximal end, a distal end and a frusto-conically shaped tip extending from said distal end having a tip passageway therethrough in fluid communication with said chamber, said chamber having an inside diameter of at least 13.5 mm (0.53 inch), said chamber having a distal end defined by a distal wall through which said tip passageway passes, the length of said chamber being no more than 57 mm (2.25 inches); a stopper in fluid-tight engagement inside said barrel; an elongated plunger rod defining a longitudinal axis and extending proximally from said stopper through said open proximal end of said syringe barrel, a flange at a proximal end of said plunger rod; a tip cap releasably connected to said tip for sealing said passageway; wherein said chamber contains flush solution in an amount less than 10 ml; (b) providing a catheter having a proximal end, a distal end and a passageway therethrough and a housing having a hollow interior in fluid communication with said passageway, said housing having a pierceable septum for allowing fluid communication with said hollow interior; (c) providing a needle assembly including a cannula having a proximal end, a distal end, and a lumen therethrough, a hub having an open proximal end containing a cavity and a distal end attached to said proximal end of said cannula so that said lumen is in fluid communication with said cavity; (d) placing said distal end of said catheter in a blood vessel; (e) removing said tip cap from said syringe barrel and attaching said needle assembly to said syringe assembly so that said frusto-conically shaped tip of said barrel is in said cavity of said hub; (f) piercing said septum with said distal end of said needle so that said lumen is in fluid communication with said hollow interior of said housing; (g) applying force to said plunger rod to move said plunger rod in a distal direction with respect to said barrel so that said flush solution in said chamber flows through said lumen of said cannula into said hollow chamber of said housing and through said passageway of said catheter such that the fluid pressure is no more than 40 psi; and (h) withdrawing said cannula from said septum.