An arterial blood gas (ABG) analysis measures pH, oxygen, and carbon dioxide levels in the blood to help diagnose respiratory and metabolic conditions. It requires collecting a blood sample directly from an artery, usually the radial artery in the wrist. Normal ABG values include a pH of 7.35-7.45, PaO2 of 80-90 mmHg, PaCO2 of 35-45 mmHg, and HCO3- of 22-26 mEq/L. Complications can include bleeding, hematoma, and infection if not performed correctly. The results are used to identify respiratory issues like hypoxia or acidosis and metabolic derangements.

1. ARTERIAL BLOOD GAS ANALYSIS
[ABG]

2. BLOOD
Blood is a connective tissue
BLOOD CONSIST OF PLASMA (55%) AND
CELLS (45%).

3. FUNCTIONS
 Transport respiratory gases
 Transport nutrients
 Act as a vehicle (hormones & vitamins)
 Drainage of waste products
Maintenance of water balance
Maintenance of acid equilibrium
Regulation of body temperature

4. COMMON TERMINOLOGIES
 ACIDS: Acid is a substance which when dissolved in
water undergoes or splits into a hydrogen ion and
anion.
 BASES: Base is a substance which undergoes
dissociation in water to give a hydroxyl ion and a
cation.
 SALTS: Salt is a substance which when dissolved in
water dissociate to release a cation and anion
neither of which is a hydogen ion nor a hydroxyl ion.

5. PH
 PH is the hydrogen ion concentration in
any solution.
1________________7________________14
Acid Base
Normal Blood PH- 7.35 – 7.45 mEq/L

6. BUFFER
Buffer is a substance which is capable of
converting strong acid into weak acid and strong
base into weak base & does not undergo rapid
ionisation & thereby does not contribute to
alteration of pH.
THREE SYSTEMS:
1.Buffer system
2.Respiratory system
3. Renal system

7. BUFFER SYSTEMS
1. Carbonic acid bi-carbonate system
2. Sodium salt of di-hydrogen and mono-hydrogen
phosphate
3. Protein buffer system

8. NORMAL ABG VALUES
pH
PaO2
PaCO2
HCO3-
Base excess
SaO2
 7.35 - 7.45
 80 - 90 mm/Hg
 35 – 45 mm/Hg
 22-26 mEq/L
 +2
 95 - 100%

9. INDICATIONS
Cardiac Failure
Renal or Hepatic Failure
Mechanical ventilation
Diabetic Ketoacidosis
Respiratory Failure Or Dysfunction.
Sepsis and burns
Poisoning
Cardiopulmonary surgery
Cardiac pulmonary exercise testing
Oxygen administration

10. CONTRAINDICATIONS:
 Patients on anticoagulant & those with
coagulopathies.
 Obstructing thrombus in the artery.
 Patients with poor collateral flow.

11. PROCEDURE OF ABG ANALYSIS
Arterial puncture sites:
Wrist :most common site used.
Radial artery
Brachial artery
Femoral artery
Dorsalis pedis artery

12. EQUIPMENTS USED:
Sterile Gloves
Heparinized syringe (2ml)
Alcohol Swabs
Gauze pieces
Tape or Plaster
Patient Label
 Ice bag or box.

13. ALLEN’S TEST

14. AFTER-CARE
Applies pressure to the puncture site for
10-15 mins to stop the bleeding.
The patient should rest quietly while applying
the pressure to the puncture site.
 Then place a dressing over the puncture.
Health care workers will observe the patient
for the signs of bleeding or circulation
problem

15. COMPLICATIONS
Hematoma
Hemorrhage
Arteriospasm
Nosocomial Bacteraemia
Distal Ischemia
Numbness of Hand
Sepsis
 Infection of health care worker.

16. UNCOMPENSATED ABG VALUES
pH PaCO2 HCO3
Respiratory
acidosis
Normal
Respiratory
alkalosis
Normal
Metabolic
acidosis
Normal
Metabolic
alkalosis
Normal

17. COMPENSATED ABG VALUES
pH PaCO2 HCO3-
Respiratory
Alkalosis
Normal
Metabolic
Alkalosis
Normal