Arterial Puncture

• The arterial puncture is used to collect blood specimen for arterial blood gas (ABG) analysis to manage cardiopulmonary disorders and maintain the acid-base balance of the body
• The arterial blood is the ideal specimen for respiratory function evaluation due to the consistency of its composition and high oxygen content
• The phlebotomist should have a thorough understanding of the arterial puncture collection procedure to minimize pain and maintain the accuracy of the results since it is more technically challenging and hazardous than venipuncture
• Arterial Blood Gas (ABG)

  Evaluation of the arterial blood gas performed to diagnose respiratory disorders, providing information about oxygenation, ventilation, and acid-base balance to help manage diseases
• The accuracy of the ABG results is easily affected by pre-analytical errors, so proper assessment of the patient and collection and handling procedures should be strictly followed
• Commonly measured ABG analytes

  • pH
  • PCO2
  • HCO3
  • O2 saturation
  • Base excess
• Health workers who collect arterial specimens should have extensive skills and knowledge on the performance of the procedure, and should undergo periodic evaluation
• Personnel who collect arterial specimens

  • Nurses
  • Medical technologists and technicians
  • Respiratory therapists
  • Emergency medical technicians
  • Level II phlebotomists
• Criteria used in selecting the site for an arterial puncture

  • There is collateral circulation
  • The artery is accessible and large in size
  • The surrounding tissue has little risk of being injured
  • The area is free from inflammation, irritation, edema, hematoma, lesion, and wound
  • There is no arteriovenous (AV) shunt near the site or no recent arterial puncture
• Arterial puncture sites

  • Radial artery
  • Brachial artery
  • Femoral artery
• Radial artery

  The most commonly used site located in the thumb side of the wrist, with good collateral circulation, easy to palpate, and less chance of hematoma formation
• Brachial artery

  Located in the medial anterior of the antecubital fossa, relatively easy to puncture and palpate due to size, sometimes the preferred artery for a large volume of blood
• Femoral artery

  Located in the groin lateral to the pubic bone, adequate collateral circulation but not as good as radial, large and easily palpated and punctured, sometimes the only site where arterial sampling is possible
• Other sites that can be used for arterial puncture include the scalp and heel for infants and the dorsalis pedis arteries for adults
• Information required for the ABG test requisition

  • Current body temperature
  • Respiratory rate
  • Ventilation status
  • Fraction of inspired oxygen (FIO2)
  • Prescribed flow rate in liters per minute
• Specimen collection equipment and supplies

  • Antiseptic for site cleaning
  • Local anesthetic (optional)
  • Short-bevel hypodermic needle with safety feature
  • 1-to 5-mL self-filling syringe
  • Luer-tip normal or bubble removal cap
  • Coolant (when applicable)
  • 2x2-inch gauze squares
  • Self-adhering gauze bandage
  • Identification and labeling materials
  • Puncture-resistant sharps container
• Patient Preparation

  1. Identification and explanation of procedure

  2. Patient preparation and assessment

  3. Steady state

  4. Modified Allen test

  5. Administration of local anesthetic (optional)
• Radial Arterial Blood Gas (ABG) Procedure

  1. Review accession test request

  2. Approach and identify patient, explain procedure

  3. Assess patient steady state, verify collection requirements

  4. Observe hand hygiene, wear gloves

  5. Verify collateral circulation

  6. Position arm, locate and clean radial artery site

  7. Administer local anesthetic if ordered

  8. Assemble ABG equipment, inspect needle

  9. Relocate radial artery, insert needle, fill syringe

  10. Remove needle, apply pressure, activate safety feature

  11. Expel air bubbles, cap and mix specimen, label

  12. Check patient's arm, apply pressure bandage

  13. Dispose of used materials, remove gloves, sanitize hands

  14. Transport specimen to laboratory immediately
• Hazards and complications of arterial puncture

  • Arteriospasm
  • Artery damage
  • Discomfort
  • Infection
  • Hematoma
  • Numbness
  • Thrombus formation
  • Vasovagal response
• Sampling errors can compromise the integrity of the blood sample and the accuracy of the ABG test results
• Criteria for rejection of ABG specimen

  • Air bubbles in the specimen
  • Specimen has clotted
  • Specimen has hemolyzed
  • Specimen did not comply with labeling requirements
  • Prescribed transportation temperature not met
  • Specimen did not meet required volume or is QNS
  • Took too long for specimen to reach the laboratory
  • Wrong type of syringe used
• Heparin-less interference is preferred for ABG specimen collection