ABG procedure for B.Sc and M.Sc. nursing students

1. VIVEKANANDA COLLEGE OF NURSING
MICRO-TEACHING PRACTICE
PRESENTED BY- APURVA DWIVEDI [M.Sc. NSG. 1ST YR.]

2. ABG
(Arterial blood gas)

3. Overview
◦ Introduction
◦ Normal range
◦ What is measured in an arterial blood gas test?
◦ Article required
◦ Procedure of ABG
◦ Venous or arterial blood?
◦ Results

4. Introduction
◦ An arterial blood gas (ABG) test measures the amounts of arterial gases,
such as oxygen and carbon dioxide.
◦ An ABG test requires that a small volume of blood be drawn from the radial
artery with a syringe and a thin needle, but sometimes the femoral artery in
the groin or another site is used. The blood can also be drawn from
an arterial catheter.
◦ An ABG test measures the blood gas tension values of the arterial partial
pressure of oxygen (PaO2), and the arterial partial pressure of carbon
dioxide (PaCO2), and the blood's ph.

5. Conti.
◦ In addition, the arterial oxygen saturation (SaO2) can be
determined. Such information is vital when caring for patients with
critical illnesses or respiratory disease. Therefore, the ABG test is
one of the most common tests performed on patients in intensive-
care units.
◦ In other levels of care, pulse oximetry plus transcutaneous
carbon-dioxide measurement is a less invasive, alternative
method of obtaining similar information

7. What is measured in an arterial blood
gas test?
An arterial blood gas test usually includes the following measurements:
• Oxygen content (O2CT): This measures the amount of oxygen in your
blood.
• Hemoglobin: This measures the amount of hemoglobin, the protein
responsible for carrying oxygen to your cells, in your blood.
• Oxygen saturation (O2Sat): This measures how much hemoglobin in your
blood is carrying oxygen. Hemoglobin is a protein in your red blood cells
that carries oxygen from your lungs to the rest of your body.

8. Conti..
• Partial pressure of oxygen (PaO2): This measures the pressure of oxygen
dissolved in your blood. It helps show how well oxygen moves from your lungs to
your bloodstream.
• Partial pressure of carbon dioxide (PaCO2): This measures the amount of
carbon dioxide in your blood and how well carbon dioxide can move out of your
body.
• pH: This measures the balance of acids and bases in your blood, known as your
blood pH level. The pH of blood is usually between 7.35 and 7.45. If it’s lower than
that, your blood is considered too acidic. If it’s higher than that range, your blood
is considered too basic (alkaline).
• Bicarbonate (HCO3): This is calculated using the measured values of pH and
PaCO2 to determine the amount of the basic compound made from carbon
dioxide (CO2.)

10. Article required
Gather the necessary following
equipment:
◦ a blue (23 G) needle
◦ 2ml syringe with heparin
◦ local anesthetic (plus needle and
syringe for giving)
◦ alcohol gauze
◦ Gloves

11. Procedure of ABG
◦ Wash your hands.
◦ Introduce yourself to the patient and
clarify their identity. Explain what you
would like to do and obtain consent.
This is a slightly uncomfortable
procedure so you should let the
patient know this.

12. ◦ Locate the radial artery with
your index and middle
fingers.

13. ◦ Perform Allen's test where you compress both the
radial and ulnar arteries at the same time.
◦ The hand should become white, release the ulnar
artery and the color should return to the hand.
◦ This ensures that there will still be a blood supply to
the hand should the ABG cause a blockage in the
radial artery.

14. ◦ Put on your gloves and attach the
needle to the heparinized syringe.
◦ Also prepare your local anesthetic and
give a small amount over the palpable
radial artery.

15. ◦ Take the cap off the needle.
◦ Flush the heparin through the syringe and again locate the radial
artery using your non-dominant hand.

16. ◦ Insert the needle at 30 degrees to
the skin at the point of maximum
pulsation of the radial artery.
◦ Advance the needle until arterial
blood flushes into the syringe.
◦ The arterial pressure will cause
the blood to fill the syringe.
◦ Remove the needle/syringe
placing the needle into the bung.
◦ Press firmly over the puncture
site with the gauze to halt the
bleeding.
◦ Remain pressed for 5 minutes.

17. ◦ Remove the needle and discard safely in the sharps bin.

18. ◦ Cap the syringe.
◦ Push out any air within it.
◦ Send immediately for analysis
ensuring that the sample is
packed in ice.
◦ Remove your gloves and
dispose them in the clinical
waste bin.
◦ Wash your hands and thank the
patient.

19. Venous or arterial blood?
◦ Dark, non-pulsatile blood that requires
manual suction to aspirate often
indicates a venous sample(except in
severe shock /cardiac arrest).
◦ Another clue is when Sao2 on ABG
analysis is significantly lower than Sao2
on pulse oximetry.

20. Results
The following information shows the changes in pH, CO2 and bicarbonate
concentrations in different situations:
Metabolic Acidosis
•pH: ↓
•pCO2: ↔
•Bicarbonate: ↓
Respiratory Acidosis
•pH: ↓
•pCO2: ↑
•Bicarbonate: ↔
Metabolic Alkalosis
•pH: ↑
•pCO2: ↔
•Bicarbonate: ↑
Respiratory Alkalosis
•pH: ↑
•pCO2: ↓
•Bicarbonate: ↔

21. Summary
◦ So we have learned about the introduction of ABG,
normal range of ABG, What is measured in an
arterial blood gas test?, blood draw points for ABG
analysis, article required for ABG procedure, steps
for procedure, Venous or arterial blood? And Results.

22. Conclusion
◦ An extension to this station may be arterial blood
gas interpretation. Before attempting to interpret
the results you should know whether the patient
was on room air or on oxygen when the sample
was taken, and if on oxygen, what concentration.
◦ It is also useful to know whether the patient has
a temperature or not, and this should be clearly
written on the sample.

23. Bibliography
Book reference
◦ ‘‘SUDDARTH’S AND BRUNNER’’, Text book of medical surgical nursing,volume-1,edition-
13,wolters Kluwer publisher, Page no. 508
Net reference
Arterial Blood Gases (ABG) — Medi students