radial art cannulation

(May-2008 Q2) Why is the radial artery a common site for arterial cannulation? What complications may occur from radial artery cannulation and how may they be minimised?

The radial artery is a common site for cannulation because it is superficial and easy to assess, distal and therefore allows more proximal arteries to be left intact in case of failing to cannulate distally, the proximal brachial artery is still available as an alternative (although this is not ideal).

It is compressible and therefore in the case of a hematoma, expansion of the hematoma may be limited by direct pressure

Clean, correlates well with BP, collateral circulation, discrete from nerves

Complications:

1) hematoma

2) thrombosis/ vasospasm/air bubbles leading to distal ischaemia

- minimized if pre cannulation allen’s test is done to ensure presence of collateral circulation to the hands prior to radial art cannulation

3) infection- this may be minimized by using an aseptic technique, vigilance for infection/ cellulitis and prompt removal of the cannula, changing the site of the cannula every week (?evidence?) strict asepsis when obtaining blood samples from cannula

4) Invasive arterial cannulation only when indicated : >4 ABG /day, hemodynamic monitoring crucial

5) Drug injection- adequate labelling, staff training, prompt recognition if drug has been given to do corrective measures