2. ABGs?
• ABG = Arterial Blood Gas, a
blood test from an artery
• Assesses oxygenation (PaO₂,
SaO₂), ventilation (PaCO₂),
acid-base status (pH, HCO₃⁻)
• Used in ICU, ER, anesthesia,
and critical care settings
3. How to take sample for ABG
✅ Preparation:
1. Verify the order and confirm patient identity.
2. Explain the procedure to the patient—it can be uncomfortable.
3. Check for contraindications, such as:
1. Inadequate collateral circulation (do Allen’s test if using radial artery)
2. Bleeding disorders or anticoagulant use
3. Infection at the puncture site
4. Gather supplies:
1. ABG syringe (pre-heparinized)
2. Alcohol/chlorhexidine swab
3. Sterile gloves
4. Gauze and bandage/tape
5. Ice if sample transport is delayed
6. Sharps container
📍 Site Selection (common arteries):
• Radial artery (preferred)
• Brachial artery
• Femoral artery (last resort, esp. in emergencies)
4. ️
🖐️Performing Allen’s Test (for radial artery):
1. Have the patient make a fist.
2. Compress both radial and ulnar arteries.
3. Have the patient open their hand (it should appear pale).
4. Release ulnar artery compression.
5. If color returns within 5–15 seconds → Positive test (good collateral circulation).
💉 Sample Collection:
6. Position the wrist extended (for radial puncture).
7. Clean the site with antiseptic.
8. Palpate the artery and insert the needle at a 30–45° angle, bevel up.
9. Let the arterial pressure fill the syringe (do not aspirate).
10.Once filled (usually 1–3 mL), withdraw the needle quickly.
11.Immediately apply firm pressure to the site for 5+ minutes (longer if on
anticoagulants).
12.Remove air bubbles, cap the syringe, and gently mix (if required).
13.Label the sample and place it on ice if delayed transport (more than 10–15
mins).
5. Indications
for ABG
Analysis
• Suspected acid-base disturbance
(e.g., DKA, renal failure)
• Respiratory distress/failure or
ventilated patients
• Monitoring oxygen therapy
• Altered mental status of
unknown cause
