ARTERIAL PUNCTURE

• Arterial Puncture


  Blood is obtained/withdrawn from a patient's artery
• Arterial Puncture Procedure

  1. Test Requisition

  2. Equipment and Supplies
• Arterial Puncture

  • Blood sample is collected without tourniquet
  • Used for Blood Gas Analysis (BGA) / Arterial Blood Gas Analysis (ABGA)
  • Arterial blood is bright red in color but venous blood is dark maroon in color
  • Medtechs/phlebotomists are not allowed to perform arterial puncture routinely
  • Only allowed to performed radial arterial puncture (if trained)
  • Performed by: MD, Nurses, Medical technologists & technicians, Respiratory therapists, Emergency medical technicians, Level II phlebotomists
  • Arterial puncture is technically difficult
  • Only MD are allowed to perform arterial puncture
  • ALL except MD cannot just do arterial puncture after graduating. They need extensive training before they can perform arterial puncture, where they are supervised by a professional
  • Even if they have already undergone a training, they still need to have a training every now and then
  • They need to have a certificate from the training

  
• Sites for Arterial Puncture

  • Radial artery
  • Brachial artery
  • Femoral artery
  • Scalp artery
  • Umbilical artery
  • Dorsalis pedis arteries
• Site-Selection Criteria


  • Presence of collateral circulation
  • Artery accessibility & size
  • Type of tissue surrounding puncture site
• Radial Artery


  • Good collateral circulation (radial & ulnar arteries)
  • Easy to palpate (close to surface of skin)
  • Less chance of hematoma formation after collection
  • Less nerve to hit
  • Requires considerable skill to puncture it successfully due to small size
  • Difficult to locate on patients with hypovolemia or low cardiac output
• Brachial Artery


  • Large & relatively easy to palpate & puncture
  • Sometimes the preferred artery for a large volume of blood
  • Adequate collateral circulation (but not as good as radial)
  • Deeper & can be harder to palpate than radial artery
  • Lies close to basilic vein; risk of mistakenly puncturing it
  • Lies close to median nerve; risk of pain & nerve damage
  • Increased risk of hematoma formation
• Femoral Artery


  • Largest artery used for arterial puncture
  • Located superficially in groin, lateral to pubis bone
  • Performed primarily by physicians & specially trained emergency room personnel
  • Generally used only in emergency situations or when no other site is available
  • Large & easily palpated & punctured
  • Poor collateral circulation
  • Lies close to femoral vein; risk of mistakenly puncturing it
  • Increased risk of infection due to location & pubic hair
  • Risk of dislodging plaque buildup from inner artery walls
  • Requires extended monitoring for hematoma formation
• Disadvantages of Arterial Puncture

  • Technically difficult
  • Potentially more painful & hazardous than venipuncture
  • Thus, not normally used for routine blood tests
• Reason for Arterial Puncture

  To obtain blood for arterial blood gas (ABG) tests
• Arterial Blood


  • Best specimen for evaluating respiratory function
  • To check for respiratory (lungs) and metabolic (kidney) function
  • To check for acid-base balance
  • Has high oxygen content & consistency of composition
• Arterial Blood Gas Analysis (ABGs)


  • Used in diagnosis & management of respiratory disorders and metabolic disorders
  • Provide valuable info. about patient's oxygenation, ventilation, and acid-base balance
  • Used in management of electrolyte & acid-base balance in patients with diabetes & other metabolic disorders
  • Specimens are sensitive to effects of preanalytical errors
• Commonly Measured ABG Analytes

  • pH
  • PaO₂
  • PaCO₂
  • HCO₂
  • O₂ sat
  • Base excess
• You cannot let air to enter because it will affect oxygen
• Required Information for Test Requisition

  • Patient's full name
  • Medical record or identification number
  • Age or date of birth
  • Room number or other patient location
  • Date and time of test collection
  • Fraction of inspired oxygen (FiO₂) or flow rate in liters per minute (L/M)
  • Body temperature
  • Respiration rate
  • Clinical indication for specimen collection (e.g. FiO₂ or mechanical ventilation change)
  • Blood drawer's initials
  • Requesting physician's name

  
• Supplemental Information as Required by Institutional Policy or Regulatory Agencies

  • Ventilation status (i.e., breathing spontaneously or mechanically supported)
  • Method of ventilation
  • Sampling site and type of procedure (i.e. arterial or capillary puncture or indwelling catheter)
  • Patient activity and position
  • Working diagnosis or ICD code
• Equipment and Supplies

  • Personal protective equipment (fluid-resistant lab coat, gown, or apron, gloves, face protection)
  • Antiseptic (isopropyl alcohol, chlorhexidine)
  • Local anesthetic (1% licocaine)
• Information to be recorded

  • Action of inspired oxygen (FiO₂)
  • Flow rate in liters per minute (L/M)
  • Body temperature
  • Respiration rate
  • Clinical indication for specimen collection (e.g. FiO₂ or mechanical ventilation change)
  • Blood drawer's initials
  • Requesting physician's name
• Supplemental Information as Required by Institutional Policy or Regulatory Agencies

  • Ventilation status (i.e., breathing spontaneously or mechanically supported)
  • Method of ventilation
  • Sampling site and type of procedure (i.e. arterial or capillary puncture or indwelling catheter)
  • Patient activity and position
  • Working diagnosis or ICD code
• Personal protective equipment


  • Fluid-resistant lab coat, gown, or apron
  • Gloves
  • Face protection
• Antiseptic


  isopropyl alcohol, chlorhexidine
• Local anesthetic


  1% licocaine
• We use anesthetic if the patient is scared or they feel pain, because hyperventilation can affect BGA
• Needle specifications


  • Gauge ranging 20-23
  • Gauge 22, 1 inch in length is the most commonly used for radial artery
  • Gauge 22, 1 ½ inch used for femoral artery
  • Smaller diameter – increased chance of producing bubbles and cause hemolysis
• Syringe


  1. to 5-mL self-filling syringe, already heparinized inside, powdered heparin is more preferred than liquid
• Luer-tip


  Used instead of recapping the needle
• Coolant


  Arterial blood is at 4°C, if no coolant, use ice slurry
• Other supplies

  • by 2-in. gauze squares for applying pressure
  • Self-adhering gauze bandage
  • ID & labeling materials (water-proof and indelible ink)
  • Puncture-resistant sharps container
• Patient Preparation

  1. Identification & explanation of procedures

  2. Patient preparation & assessment (ask about allergies, fasting, medications)

  3. Assess steady state (breathing pattern, oxygen saturation)

  4. Perform modified Allen test

  5. Administer local anesthetic (optional)
• Modified Allen Test Procedure

  1. Have patient make a tight fist

  2. Compress patient's radial & ulnar arteries at same time

  3. Maintaining pressure, have patient open hand slowly

  4. Lower patient's hand & release pressure on ulnar artery only

  5. Assess results: (+) hand flushes pink; (-) hand does not flush pink
• 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. Clean & air-dry site

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

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

  9. Wait 1 to 2 min. before proceeding with arterial puncture
• Radial ABG Procedure

  1. Review & accession test request

  2. Approach, identify, & prepare patient

  3. Check for sensitivities

  4. Access steady state, verify collection requirements, & record info

  5. Sanitize hands & don gloves

  6. Assess collateral circulation

  7. Position arm & ask patient to extend wrist

  8. Locate radial artery & clean site

  9. Administer local anesthetic (optional)

  10. Prepare equipment & clean gloved non-dominant finger

  11. Pick up equipment & uncap & inspect needle

  12. Relocate radial artery & warn patient of imminent puncture

  13. Insert needle at a 30- to 45-degree angle, slowly direct it toward pulse, & stop when a flash of blood appears

  14. Allow syringe to fill to proper level

  15. Place gauze, remove needle, activate safety feature, & apply pressure

  16. Remove & discard syringe

  17. Expel air bubbles, cap syringe, mix, & label specimen

  18. Check patient's arm & apply bandage

  19. Dispose of used & contaminated materials, remove gloves, & sanitize hands

  20. Thank patient & transport specimen to lab ASAP
• Hazards and Complications

  • Arteriospasm
  • Artery damage
  • Discomfort
  • Infection
  • Numbness
  • Thrombus formation
  • Vasovagal response
• Sampling Errors

  • Air bubbles
  • Delay in analysis
  • Improper mixing
  • Improper syringe
  • Obtaining venous blood by mistake
  • Use of improper anticoagulant
  • Use of too much or too little heparin

  
• Criteria for Rejection

  • Air bubbles in the specimen
  • Clotted specimen
  • Hemolysis of the specimen (if electrolytes are ordered)
  • Improper or absent ID or other labeling requirements
  • Improper transportation temperature
  • Inadequate volume of specimen for the test (QNS)
  • Prolonged delay in delivery to the lab
  • Wrong type of syringe used