The document outlines the learning objectives for students studying arterial blood gas (ABG) analysis, including its definition, purpose, related terms, and the significance of various measurements like pH, pCO2, and pO2. It explains the importance of ABG analysis in managing patients with respiratory and metabolic issues, detailing conditions that may necessitate such evaluations. Additionally, it addresses technical considerations for conducting ABG tests to ensure accurate results.

1. ABG ANALYSIS
DEPARTMENT
OF
MEDICAL SURGICAL NURSING

2. Learning Objectives
At the end of this lecturer, students should be able
to:
• define ABG analysis
• enlist the purpose of ABG analysis
• explain the terms related to acid and base analysis.
• describe the respiratory and metabolic, acidosis
and alkalosis.

3. DEFINITION
Measurements of blood pH and of
arterial oxygen and carbondioxide tensions are
obtained when managing patients with
respiratory problems and in adjusting oxygen
therapy as needed.

4. • The arterial oxygen tension (PaO2) indicates
• the degree of oxygenation of the blood,
• and the arterial carbon dioxide
tension(PaCO2) indicates the adequacy of
alveolar ventilation.

5. Patients need ABG analysis
• Patient with severe blood loss/ hemorrage
• Respiratory failure/arrest
• COPD, ARDS, shock
• Asthama
• Patient is on VENTILATORY support
• Kidney failure
• Cardiac arrest
• Any drugs overdoses etc.

6. Purpose of ABG Analysis
• Aids in establishing a diagnosis
• Helps guide treatment plan
• Aids in ventilator management
• Improvement in acid/base management
• Acid/base status may alter electrolyte
levels critical to patient status/care.

7. From where we obtain blood
• Arterial blood gas levels are obtained
through an arterial puncture at the
• radial,
• brachial,
• femoral artery
• through an indwelling arterial catheter

8. Technical Errors
• Excessive Heparin
• Ideally : Pre-heparinised ABG syringes
• Syringe FLUSHED with 0.5ml 1:1000 Heparin
& emptied
• Do Not Leave Excessive Heparin In The
Syringe Heparin Dilutional Hco3 - Effect Pco2

9. Technical Errors
• Risk of alteration of results with:
1) size of syringe/needle
2) vol of sample
3) Syringes must have > 50% blood
4) Use only 3ml or less syringe
5) 25% lower values if 1 ml sample taken in 10
ml syringe (0.25 ml heparin in needle)

10. • Air Bubbles
1. pO2 150 mm Hg & pCO2 0 mm Hg
2. Contact with AIR BUBBLES
3. Seal syringe immediately after sampling
• Body Temperature
1. Affects values of pCO2 and HCO3 - only
2. ABG Analyser controlled for Normal Body
temperatures

11. • WBC Counts
• 0.01 ml O2 consumed/dL/min
• Marked increase in high TLC/plt counts : pO2
• Chilling / immediate analysis

12. ABG component
• pH: measures hydrogen ion concentration in the
blood, it shows blood’ acidity or alkalinity
• PCO2 : It is the partial pressure of CO2 that is
carried by the blood for excretion by the lungs,
known as respiratory parameter
• PO2: It is the partial pressure of O2 that is
dissolved in the blood , it reflects the body ability
to pick up oxygen from the lungs
• HCO3 : known as the metabolic parameter, it
reflects the kidney’s ability to retain and excrete
bicarbonate

13. Normal values:
• pH = 7.35 – 7.45
• PCO2 = 35 – 45 mmHg
• PO2 = 80 – 100 mmHg
• HCO3 = 22 – 28 mEq/L

15. THE TERMS:
• ACIDS
Academia
Acidosis
• Respiratory : CO2
• Metabolic: HCO3

16. • BASES
– Alkalemia
– Alkalosis
• Respiratory: CO2
• Metabolic: HCO3

17. RESPIRATORY ACIDOSIS:
• ph, CO2, Ventilation
• Causes
– CNS depression
– Pleural disease
– COPD/ARDS
– Musculoskeletal disorders

18. RESPIRATORY ALKALOSIS:
• pH, CO2, Ventilation
•  CO2  HCO3 (Cl to balance charges
hyperchloremia)
• Causes
– Intracerebral hemorrhage
– Salicylate and Progesterone drug usage

19. • Anxiety, lung compliance
• Cirrhosis of the liver

20. METABOLIC ACIDOSIS:
• PH, HCO3
Causes:
• diarrhea, lower intestinal fistulas,
ureterostomies, and use of diuretics; early
renal insufficiency; excessive administration of
chloride; and the

21. • administration of parenteral nutrition without
bicarbonate or bicarbonate-producing solutes
(e.g., lactate).

23. Summary
• So far we have discussed about Definition,
purpose, terms of ABG analysis.

24. Bibliography
• Lewis et al, Medical Surgical Nursing, Mosby
Elsevier,7th edition.
• Joyce.M.Black et al, Medical Surgical
Nursing, Saunders publication.
• Brunner and Siddhartha, Medical Surgical
Nursing, Lippincott Williams and Wilkins.

25. Thank You