Final

• Arterial Puncture Procedures


  • Technically difficult
  • Potentially more painful
  • Hazardous than venipuncture
• Arterial specimens are not normally used for routine blood tests, even though arterial blood composition is more consistent throughout the body than venous, which varies relative to the metabolic needs of the area it serves
• Primary reason for arterial puncture

  To obtain blood for arterial blood gas (ABG) tests, which evaluate respiratory function
• Arterial blood


  Best specimen for evaluating respiratory function because of its normally high oxygen content and consistency of composition
• Capillary blood


  Similar to arterial blood in composition provided that the puncture site is warmed prior to specimen collection, is sometimes used to test blood gases in infants
• Personnel who may perform arterial puncture

  • Nurses
  • Medical technologists and technicians
  • Respiratory therapists
  • Emergency medical technicians
  • Level II phlebotomists
• Phlebotomists who collect arterial specimens

  • Must have extensive training involving theory, demonstration of technique, observation of the actual procedure, and performance of arterial puncture with supervision before performing arterial punctures on their own
• Personnel who perform ABG testing

  • Level I
  • Level II (supervise level 1 personnel and perform testing as well)
• For quality assurance purposes, individuals performing arterial puncture must undergo periodic evaluation. Those who do not meet acceptable standards must have remedial instruction and be re-evaluated before being allowed to collect arterial specimens independently
• Artery used for collection

  • Must be located near the skin surface and be large enough to accept at least a 23-gauge needle
  • The region distal to the collection site should have collateral circulation, meaning that it receives blood from more than one artery
• Collateral circulation


  Tested using the modified Allen test
• Factors in site selection

  • Artery accessibility and size
  • Type of tissue surrounding the puncture site
  • Absence of inflammation, irritation, edema, hematoma, lesion or a wound, an arterioventricular (AV) shunt in close proximity, or a recent arterial puncture at the site
• Arteries used for arterial puncture

  • Radial
  • Brachial
  • Femoral
  • Dorsalis pedis (in adults)
  • Umbilical and scalp (in infants)
• Radial artery


  Artery of choice, has good collateral circulation and is easily accessible along the thumb side of the wrist
• Brachial artery


  • Large, easy to palpate and puncture, but deep and close to the median nerve, and lies in soft tissue making it more difficult to compress
• Femoral artery


  • Largest artery used, but has poor collateral circulation, difficult to keep aseptic, and the puncture may dislodge accumulated plaque from the arterial walls
• Dorsalis pedis artery


  Alternative site in adults, requires checking the posterior tibial pulse
• Umbilical artery and vein


  Used in newborns who have difficulty breathing, samples tested separately and results compared
• Equipment for arterial puncture

  • Heparinized syringe and needle
  • Antiseptic (alcohol, povidone-iodine, chlorhexidine)
  • Lidocaine anesthetic
  • Safety equipment (fluid-resistant gown, face protection, gloves, puncture resistant container for sharps)
  • Luer tip
  • Other equipment (crushed ice, ice and water, gauze pads, pressure bandages, thermometer, transport container)
• Pre-analytical procedures


  1. Identification & explanation of procedures

  2. Patient preparation & assessment

  3. Steady state
• Preparing and administering local anesthetic

  1. Verify absence of allergy

  2. Sanitize hands & don gloves

  3. Attach needle to syringe

  4. Clean stopper of anesthetic bottle

  5. Insert needle through bottle stopper & withdraw anesthetic

  6. Carefully replace needle cap & put syringe in horizontal position

  7. Clean & air-dry site

  8. Insert needle into skin at site at angle of 10 degrees

  9. Pull back slightly on plunger

  10. Slowly expel contents into skin, forming a raised wheal

  11. Wait 1 to 2 min. before proceeding w. arterial puncture

  12. Note anesthetic application on requisition
• Modified Allen test


  Most common method used to assess the adequacy of collateral circulation in the radial artery
• Radial arterial blood gas procedure

  1. Position the arm

  2. Locate the artery

  3. Clean the site
• Position the patient's arm

  1. Arm out to the side, away from the body (abducted)

  2. Palm facing up

  3. Wrist supported (rolled towel under wrist)
• Ask the patient to extend the wrist

  1. Approximately 30-degree angle

  2. Stretch and fix the tissue over the ligaments and bone of the wrist
• Locate the Artery


  1. Use index finger of nondominant hand

  2. Palpate the radial artery pulse proximal to the skin crease on the thumb side of the wrist

  3. Determine size, direction, and depth
• Never use the thumb to palpate, as it has a pulse that can be misleading
• Clean the Site


  1. Prepare the site by cleaning with alcohol or another suitable antiseptic

  2. Allow the site to air dry, being careful not to touch it with any unsterile object
• Prepare Equipment


  1. Attach the safety needle to the syringe if not pre-assembled

  2. Set the syringe plunger to the proper fill level if applicable

  3. Put on gloves and clean the gloved non-dominant finger
• Insert the Needle


  1. Pick up and hold the syringe or collection device in dominant hand

  2. Uncap and inspect the needle

  3. Relocate the artery with index finger

  4. Warn the patient and ask to relax wrist

  5. Direct the needle away from the hand, facing into the arterial blood flow

  6. Insert the needle bevel-up at 30- to 45-degree angle (90-degree for femoral puncture)
• Do not probe. Probing is painful and can cause hematoma or thrombus formation or damage the artery
• Advance the Needle into the Artery

  1. Slowly advance the needle toward the pulse

  2. When the artery is pierced, a "flash" of blood will appear in the needle hub

  3. Stop advancing the needle

  4. Do not pull back on the syringe plunger

  5. Blood will pump into the syringe under its own power unless a needle smaller than 23-gauge is used, in which case a gentle pull on the plunger may be required
• Withdraw the Needle and Apply Pressure


  1. Withdraw the needle

  2. Immediately place a folded clean and dry gauze square over the site with one hand

  3. Activate the needle safety device with the other hand

  4. Apply firm pressure to the puncture site for a minimum of 3 to 5 minutes
• Longer application of pressure is required for patients on anticoagulant therapy
• Never allow the patient to apply the pressure. A patient may not apply it firmly enough
• Do not replace use of manual pressure for the required length of time with the application of a pressure bandage
• Remove Air, Cap Syringe, and Mix Specimen


  1. Remove the safety needle and discard it

  2. Handle the specimen carefully to avoid introducing air bubbles

  3. If any air bubbles are present, immediately eject them

  4. Cap the syringe and gently but thoroughly mix the specimen by inversion or rotation to prevent clot formation

  5. Label the specimen
• Check the site


  1. After applying pressure for 3 to 5 minutes, check the site

  2. The skin below the site should be normal in color and warm to the touch, with no evidence of bleeding or swelling

  3. If bleeding, swelling, or bruising is noted, reapply pressure for an additional 2 minutes

  4. Check the pulse distal to the site
• If the pulse is absent or faint or the patient complains of numbness at the site, alert the patient's nurse or physician immediately, because a thrombus may be blocking blood flow
• Never leave the patient if the site is still bleeding. If bleeding does not stop within a reasonable time, notify the patient's nurse or physician