How to take an arterial blood gas sample
Other platforms explain it with text and video. In Making Synapses you practice it on the patient.
An arterial puncture hurts more than a vein. Explain, use local anesthetic if allowed, and press long enough afterward.
Step by step
Explain and check
Identify the patient, check anticoagulants, note the oxygen they are on. [1]
Collateral flow
Check blood flow to the hand (modified Allen test) per local policy. [1]
Position
Wrist slightly extended on a rolled towel; feel the radial pulse. [1]
Insert
Heparinized syringe, bevel up, 30 to 45 degrees toward the pulse; blood fills on its own. [1]
Press
At least 5 minutes, longer on blood thinners. [1]
Handle the sample
Remove air, cap, label, send right away (on ice if delayed, per lab). [1]
Common errors
- Not pressing long enough.
- Air bubbles in the sample.
- Not recording the oxygen.
Practice it in Making Synapses
In Making Synapses you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.
Making Synapses cases that train this skill
- COPD with pneumonia
- COPD exacerbation
- Diabetic ketoacidosis
- Atrial flutter
- Vertebral compression fracture
- COPD exacerbation (clinic)
8 Making Synapses cases train this skill: open the case library
Sources
- AAMC Core Entrustable Professional Activities (Core EPAs)
- Open RN, Nursing Skills 2e (Chippewa Valley Technical College) (CC BY 4.0)
- OpenStax, Clinical Nursing Skills (reference)
Steps adapted from Open RN, Nursing Skills 2e (Chippewa Valley Technical College), licensed under CC BY 4.0. Facts and steps also follow OpenStax, Clinical Nursing Skills (reference). Making Synapses is not affiliated with these organizations. Updated: 2026-10-11.