Pulmonary Diagnostic Testing Flashcards
Arterial puncture
Puncture of the peripheral artery to obtain an arterial blood sample for direct measure of PH, PaCO2, PaO2
What is the indication for blood gas?
1) Evaluate the adequacy of patient PaCO2, PaO2, and PH
2) Assess the need for therapeutic intervention and diagnostic (i.e. oxygen, MV)
3) Monitor the severity and progression of a document disease process
3 primary sites for obtaining an ABG?
1) Radial
2)Brachial
3) Femoral- BP low (60/40)
Why radial artery the first choice for ABG?
Accessibility and collateral blood flow
Modified allen test
Access the collateral circulation in the hand prior to drawing a radial ABG
What does a positive modified Allen test confirm?
Collateral blood flow is present
What happens after releasing pressure from the ulnar artery?
The hand pink up within 1-2 seconds
What kind of patient should never attempt arterial puncture?
Patient with indwelling dialysis shunt on radial or brachial, use another site
Hazards or problems of ABG sample
1) Disrupting blood flow- hematoma
2)Clotting
3) Bleeding - hold pressure on site for 5 min
4) vessel spasm
5) Tissue Trauma - muscles, bone, nerves
6) Anticoagulant therapy (heparin)-apply pressure to site longer.
Hazards/problems for air bubbles, improper cooling, and too much liquid heparin ABG sample
1) Air bubbles:
PaCO2 decreases towards o torr
PaO2 increase/decrease towards 150 torr
PH increases
2) Improper cooling (sample not iced) :
PaCO2 increase
PaO2 decrease
PH decreases
3) Too much liquid heparin:
PaCO2 decreases toward
0 torr
PaO2 increase/decrease towards room air 150 torr
PH decrease towards 7.0
What is the use of capillary sample infants?
Capillary samples or heal stick can be use to obtain blood gas
What are the steps to achieve a capillary sample?
1) Arterialized by wrapping it in wet warm cloth at 45-degree celsius 5-7 minutes
2) heal cleansed with alcohol and lancet use for the puncture.
What two result in the capillary sample has a consistent correlation with arterial blood gas sample?
PH and PaCO2
Which capillary sample does not correlate with arterial blood gas even when the arterial is above 60 torr?
PaO2
What blood gas sample should not monitor oxygen therapy?
PaO2
