Term | Definition |
Methods | -Percutaneous Stick
-Arterial Line
-Umbilical catheter
-Capillary |
Indications | -Evaluate the Adequacy of Acid-base (pH, PaCO2, and HCO3), Ventilation (paCO2), and oxygenation (PaO2, and O2Hb)
-Determine the response to therapeutic intervention
-Monitor Severity and Progression of a disease process |
Therapeutic Interventions | -Supplemental Oxygen
-Mechanical Ventilation
-Diagnostic Evaluation (exercise desaturation) |
Contraindications for ABG | -Negative modified Allen Test
-Arteriovenous shunt (dialysis patient)
-Improperly functional gas analyzer
-Specimen not properly anticoagulated
-Visible air bubbles
-Incomplete requisition (interpretation and documentation)
-unlabeled specimen |
Hazards of ABG Puncture | -Infection of technician (needlestick)
-Inappropriate medical treatment
-Vessel spasm
-Hematoma
-Laceration of the artery
-Hemorrhage
-Vasovagal reaction
-Loss of Limb |
Equipment and Supplies | -ABG syring (3-5 cc pre-heparinized)
-Needle (1-1.5 inch, 22 gauge)
-Needle protection device
-alcohol
-gauze
-band-aid
-gloves
-rubber stopper
-biohazard bag
-ice container |
Glass Syringe | -Not gas permeable
-results remain stable
-if analysis cannot be performed in 30 minutes
-place in ice/water slush to prevent metabolism changes
-can remain stable iced for up to 2 hours |
Plastic Syringe | -gas permeable
-most common
-don't ice
-results main stable for 30 minutes |
Heparin | prevents blood sample from clotting |
Lithium Heparin | -lypholized (dry)
-used if running electrolyte panels
-premeasured amounts for preventing dilution of samples
-white dot |
Sodium Heparin | -usually in solution
-can affect pH result
-affects the electrolyte panels
-used primarily with arterial lines |
Adult Site Selection Sites | -Radial (site of choice)
-Brachial
-Femoral
-Popliteal
-Dorsalis Pedis |
Pediatric Site Selection | -Radial
-Brachial
-Capillary |
Neonates/Newborn Site Selection | -Umbilical
-Radial
-Capillary |
How long should it take for color to return in a Modified Allen's Test? | 10 seconds |
What do you palpate to determine? | -size
-direction
-depth |
What do you clean the site with? | -alcohol
-betadine |
Which angle is the needle inserted at? | -30-45 degree angle |
How long should you apply pressure over the puncture site in normal individuals? | 5 minutes |
How long should you apply pressure over the puncture site in individuals on anticoagulants? | 10-15 minutes |
How do you mix the specimen? | -inversion or rotation |
Labeling Information | -Date and Time
-Name
-FMP/SSN
-Puncture sites
-FIO2 or O2 liter flow
-ventilator setting
-Patient Temperature
-Technician Name
-Ordering Physician |
Brachial Artery | -Major artery of the upper arm
-divides into radial and ulnar just below the elbow |
Indication for Sticking the Brachial Artery | -The radial arteries are unsuitable
-Negative Allen Test |
Hazards of Sticking the Brachial Artery | -Deeper Vessel
-Harder to stabilize
-More susceptible to hematoma
-Median nerve damage
-No collateral circulation |
Where do you palpate on for the Brachial Artery? | -antecubital fossa |
Where do you follow the arterial pulse on the brachial artery? | -2-3 cm Proximally |
What angle do you use for the Brachial artery? | -45 degree angle |
When must a sample be analyzed immediately regardless of syringe? | -paO2 > 150 mmHg |
Sampling Errors (Pre-analytic) | -Air bubbles (most common)
-delay in analysis
-Improper Mixing (heparin unmixed)
-Improper syringe
-Venous Sample
-Improper anticoagulant (sodium heparin)
-Too little heparin (clots in machine)
-Too much heparin (dilutes sample) |
Gas Tensions in the Air (Bubble) | -O2: 150 mmHg
-CO2: essentially zero
-N2 - inert |
Gas Tensions in Arterial Blood | -O2: normal 80-100 mmHg
-CO2: normal 35-45 |
CO2 effect | -CO2 diffuses out of the blood into the sample decreasing the PaCO2
-increases the pH of the sample |
O2 effect | -normally O2 in the bubble has a higher tension than the sample so O2 wil diffuse out of the bubble into the sample
-increases measured PaO2 |
Hyperoxygenated patient | 500-600 mmHg
-paO2 will decrease due to diffusion |
Capillary Sampling | -an arterial blood gas sampling in infants
-correlates wtih PacO2 and pH
-does not correlate well with PaO2 |
Indications for Capillary Sampling | -ABG analysis is needed but arterial access is not available
-May only need to look at ventilation
-Non-invasisve monitors are inaccurate or abnormal |
Contraindications for Capillary Sampling | -not performed at the certain sites
-patients less than 24 years old
-When there is a need for accurate analysis of oxygenation |
Sites NOT to be used for Capillary Sampling | -posterior curvature of the heel
-fingers of neonates
-previous puncture sites
-swollen or edematous tissue
-cyanotic poorly perfused tissue
-areas of infection
-peripheral arteries |
Hazards of Capillary Sampling | -infection
-burns
-hematoma
-nerve damage
-pain
-bleeding |
Equipment | -gloves
-pre-heparinized glass capillary tube
-metal flea and magnet (for mixing sample)
-lancet
-gauze
-warming pack/moist warm diaper
-band-aid
-alcohol pad |
What is the heat limit for capillary sampling? | -not higher than 42 degrees celsius |
What is the puncture limit for capillary sampling? | -not deeper than 2.0 mm |
What must you not do at the site for capillary sampling? | -do not squeeze the site to increase blood flow
-results in excess amounts of serous fluid and venous contamination of the sample |