Peripheral cannula[edit]
20 gauge peripheral IV in hand
A nurse inserting an 18-gauge IV needle with cannula.
A peripheral cannula is the most common intravenous access method utilized in both hospitals and pre-hospital services. A peripheral IV line (PVC or PIV) consists of a short catheter (a few centimeters long) inserted through the skin into a peripheral vein (any vein not situated in the chest or abdomen). This is usually in the form of a cannula-over-needle device, in which a flexible plastic cannula comes mounted over a metal trocar. Once the tip of the needle and cannula are introduced into the vein via venipuncture, the cannula is advanced inside the vein over the trocar to the appropriate position and secured, the trocar is then withdrawn and discarded. Blood samples may be drawn directly after the initial IV cannula insertion.
Any accessible vein can be used although arm and hand veins are used most commonly, with leg and foot veins used to a much lesser extent. In infants the scalp veins are sometimes used.