Peripheral vascular (vein & arterial) catheter

1. typically 16–20 gauge catheters that are 1–2 inches in length.

2. inserted using a catheter-over-needle device

catheter-over-needle device

3. Flow Characteristics in Peripheral Vascular Catheters

Flow Characteristics in Peripheral Vascular Catheters

4. intended for short-term use (hours to days) because the plastic polymers provoke a strong inflammatory reaction and it's easy to dislodge

Central venous catheters

1. length: 15-30cm；The 20 cm catheter is long enough for most cannulation（including the left-sided）

2. triple-lumen catheters are the most popular 

3. Size：These catheters are available in diameterss of

4 French to 9

French, and the 7 French size (outside diameter = 2.3 mm) is a popular choice in adult

4. insertion technique: 

    seldinger technique

    1) guide wire through needle access 

     2)  dilation of the tract

     3） cannulation over the wire

     4） removal of the guidewire