Intravenous cannulation: a different approach.

This article presents a different method of venous cannulation. It has been used successfully to teach dental residents working on pediatric and developmentally disabled patients. The technique includes using a syringe of 1% lidocaine hydrochloride attached to a 25-ga needle to produce a skin wheal by "jet injection." This is accomplished by placing the bevel of the needle downward and forcing the syringe in a downward and backward direction, with pressure being continuously exerted on the plunger. A 20-ga, 1 1/4-inch catheter is then attached to the syringe containing the remaining lidocaine hydrochloride. The catheter is bent, with its bevel up, approximately three-fourths of the way from the tip to form a gradually sloping bend of approximately 40 degrees to 45 degrees. The catheter is then inserted into the skin wheal and advanced into the vein. The advantages of this technique are that it (1) can eliminate the pain associated with a subcutaneous infiltration of a local anesthetic solution, (2) provides a method of venous cannulation that is easier to master by the novice, and (3) gives a visual check on successful catheterization of the vein.