What is it?
Cannulation of a peripheral artery
- allows constant BP monitoring
- repeated ABG sampling
Usually via radial or dorsalis pedis
- avoid femoral and brachial (lack collaterals)
- femoral has sepsis risk
Local sepsis and coagulopathy
Haematoma, thrombosis, distal ischaemia, intimal damage, aneurysm
formation, disconnection and injection of irritant drugs.
Test collateral circulation with Allen's Test
Use a 20-22g cannula.
Ensure light, comfort and assistance
Palpate the artery with two fingers
- feel and imagine its course
Insert at 45o
Puncture the artery
- advance guidewire
- railroad the cannula
- check backflow and secure the cannula
Connect transducer and flush
For BP measurement
Connect via a short rigid length to a 3-way tap, flush device and
- zero and calibrate the transducer
- the shape of the wave is important, eg sharp peaked upswing and low
dicrotic notched downswing may indicate hypovolaemia.
Care of the line
Connect to a hep saline continuous flush device
- this keeps it patent
- and allows BP measurement without letting blood out into the line.