Arterial Puncture

1. Indications
   1. Arterial Blood Gas
2. Sites of sampling
   1. Radial artery
   2. Other sites (higher risk of neurovascular injury)
      1. Brachial artery
      2. Femoral artery
3. Technique: Preparation for Radial Artery Puncture
   1. Perform Allen Test to confirm collateral circulation
   2. Heparinize syringe
      1. Start with 3 cc Syringe and 21 gauge needle
      2. Draw up 0.5 ml of Heparin (1000 units/ml)
      3. Rotate syringe and work plunger to distribute Heparin
      4. Minimal Heparin should remain (0.15 ml)
   3. Clean radial entry site
      1. Povidone-Iodine solution (betadine)
      2. Alcohol swab
   4. Consider local anesthetic at entry site
      1. Small skin wheal of Lidocaine 1%
4. Technique: Obtaining Radial Artery Sample
   1. Needle entry
      1. Identify radial artery with gentle pressure
      2. Patient dorsiflexes wrist
      3. Needle and syringe angled 45 degrees toward arm
      4. Enter skin just distal to palpated artery site
      5. Slowly advance needle until spontaneous blood enters
   2. Arterial Blood Collection
      1. Hold needle steady until 1-2 cc blood obtained
      2. Allow syringe to fill itself (avoid aspirating)
      3. If flow ceases
         1. Slowly withdraw needle 1-2 mm
         2. Repositions needle back inside arterial lumen
5. Technique: Completing Sample Collection
   1. Withdrawing needle
      1. Withdraw needle from skin
      2. Immediately apply pressure over entry site
      3. Hold pressure at entry site for 5 minutes
   2. Sample preparation for lab
      1. Express any air bubbles from syringe
      2. Cork needle or remove needle and cap syringe
      3. Roll syringe between fingers to mix Heparinize sample
      4. Immediately place sample on ice
   3. Label Sample
      1. Patient identification data
      2. Sample acquisition time
      3. FIO2 at time of sample draw
      4. Patient's body temperature
   4. Deliver sample quickly to the lab
6. Complications
   1. Nerve Injury
   2. Ischemic changes hand and wrist
      1. Always check Allen Test before radial artery puncture
   3. Occult bleeding
      1. Especially at brachial and femoral artery punctures