Abstract: An instrument for achieving rapid hemostasis at the conclusion of a catheterization procedure comprising a hemostatic agent injection device for use with a conventional introducer sheath used to gain access to the blood vessel. The injection device includes an elongated tubular member having ejection ports proximate its distal end. A hub member is located on the proximal end of the tubular member and includes an elongated groove or track located in its surface with a transparent cover. The enclosed track is in fluid communication with the lumen extending through the tubular member. After the catheterization procedure, the instrument is inserted into the introducer sheath. Blood flows into the lumen of the device and into the enclosed track. The leading edge of the blood pulsates within the enclosed track, clearly indicating that the ports are located in the blood vessel and subjected to variations in blood pressure.