1. Ask the patient to clench her fist. Stretch the extremity and vein while placing the fingers of your non-dominant hand on top of the vein where the shaft of the cannula will lie. Using moderate pressure, retract the skin away from the insertion site to stabilize the vein. Grasp the cannula with your fingers touching only the hub, so you can easily see blood backflow. Aim the cannula tip at the vein you feel under your fingers and insert it in one smooth, aggressive motion.
2. Use your non-dominant hand to maintain vein stretch. Lower the cannula angle and continue advancing the cannula until you see blood backflow in the hub, indicating that the cannula tip has entered the vein.
3. Place a protective pad under the hub, then remove the stylet. As you remove the stylet, blood will flow into the flashback chamber. If the vein or cannula is large, the chamber can fill very rapidly. Remove the tourniquet and connect the M. tubing to the hub, as shown here. Remove your gloves, apply a dressing, tape, and label, and document the procedure.