Choosing the correct I.V catheter
Understanding catheter sizing is important. Not knowing what size catheter to use and why, can lead to catheter failures.
So how do you choose the correct catheter?
Catheters come in many sizes and there is a reason for this. Not all veins are the same size! Ideally, a catheter should not take up more than 50-60% of the vein it is intended for. For example, if the catheter size chosen is 0.7mm (24G) then the vein should be around 1.4mm. A catheter that is too large for the vein, is an obstruction.
| Too large | Too small |
| Vein puncture that can lead to a blown leg | Inadequate dosages; if the catheter is too small, it can lead to inadequate fluid therapy and a very slow release of medications and drugs |
| Phlebitis; a catheter that can rub along the wall of the vein can cause inflammation, infection and possible rupture of the vein. | Damaged blood cells if blood draw is taken |
| Incorrect medication or fluid dose; causing an obstruction of blood flow. Without good blood flow, fluids and medications may have restricted movement through the body. | Pressure alarms on infusion devices |
Placing a catheter correctly:
When placing your catheter, it is important to enter the vein at the correct angle and depth, with the bevel facing upwards. The ideal angle is between 10-30 degree and 0.6 to 4.6cm in laterial vein depth, dependent on the choice of catheter.