Catheters are small, flexible plastic tubes. They are commonly inserted into veins or arteries (intravascularly) to deliver fluid or drugs directly into the bloodstream or to help perform special tests. Intravascular catheters are normally inserted through the skin. The skin's surface has bacteria that can cause infection. Antiseptic preparations are used to clean the skin around the area where catheters are inserted. These preparations contain chemicals that kill or prevent growth of bacteria. The main aims of antiseptic use are to “disinfect skin” and to stop bacteria from entering the bloodstream and causing serious infection. There are many kinds of antiseptics. Two types that are used in many hospitals are chlorhexidine gluconate and povidone-iodine. Several studies have compared the ability of these two preparations to prevent serious infection from occurring with intravascular catheter use.