Radial Artery Blood Gas Sampling

The radial artery is a superficial artery located on the wrist, on the thumb side of the hand. This is the most common site for ABG sampling.
Modified Allen’s test
Wash hands
Expose your wrist and place a pillow beneath it
Perform modified Allen’s test
With the patient’s palm facing upwards, occlude both radial and ulnar arteries
Ask the patient to open and close their hand until the palm becomes pale, then ask them to hold it open
Release the ulnar artery and time how long the hand takes to reperfuse (i.e. become pink again)
If ≤10 seconds, continue with ABG
Preparation
Firmly hyper-extend the patient’s wrist (ask them, or hold it down yourself)
A palpated radial artery with index and middle fingers
Wash hands
Put on gloves
Sterilize the area using a skin-cleansing wipe (clean for 30 seconds, then allow to air-dry for 30 seconds)
Expel air from the heparinized syringe (only necessary for some ABG kits)
Sampling
With the index and middle fingers of your non-dominant hand, re-palpate the artery just proximal to the point of insertion
Holding the bevel of the needle as close to your non-dominant hand’s fingers as possible (without touching them), insert the needle (bevel up) into the site of pulsation, at 45˚ to the skin
When blood enters the syringe, hold it still while it self-fills (no need to aspirate)
Place gauze loosely over the puncture site while you remove the needle. Then apply pressure to the gauze once the needle is fully removed.
Secure the needle with a rubber block or needle cover
Maintain pressure over the gauze for 5 minutes. Check it has stopped bleeding before taping down the gauze.