proximal end cap connector 8 of fig1 which is part of the aforementioned assembly containing the cotton and deae the item of 29 represents the completed catheter assembly discussed above fig3 represents the completed apparatus assembly in place within the introducer and patient as it would typically be used catheter 29 is shown placed through the introducer 32 with proximal end 33 snap fitted to the catheter and extending beyond the distal end 34 until port 21 is in fluid communication with the inside of artery 36 which is substantially enclosed within living tissue 35 accordingly blood fluid flows through port 21 up through catheter 29 and into the pulsatile indicator 16 and the containing apparatus assembly 31 the arterial systolic diastolic pressure variation causes blood fluid within the pulsatile indicator 16 to vary compression of the entrapped air space within 16 thus providing positive indication of the presence of port 21 within the artery the three way valve of 31 is turned to permit withdrawal of the syringe plunger thereby encouraging blood fluid to flow through the cotton and deae cellulose as this occurs trapped air within the syringe may be exhausted by switching the three way valve to the exhaust side and advancing the plunger once substantially exhausted of air the three.