What is the recommended method to minimize air exposure during arterial puncture for ABG collection?

• A. Fill a heparinized syringe without introducing air bubbles
• B. Draw into a plain glass syringe and seal
• C. Expose the sample to room air briefly during transport
• D. Use a citrate-containing tube

Answer: (A)

Minimizing air exposure and preventing clotting are essential for accurate arterial blood gas results. Arterial blood gases (pO2, pCO2, pH) are highly sensitive to gas exchange with the environment and to clotting, which can alter the sample’s composition. Filling a syringe that is already heparinized and avoiding any air bubbles ensures the blood remains fluid and its gas content remains representative of the patient at the moment of collection. The heparin prevents clot formation, so the sample can be analyzed without interference from a clot, and keeping it free of air bubbles prevents artificial shifts in oxygen and carbon dioxide levels.

Using a plain glass syringe without an anticoagulant risks clotting, which can skew measurements or require a repeat draw. Exposing the sample to room air during transport allows diffusion of gases, changing pO2 and pCO2 and yielding inaccurate results. A citrate-containing tube is not suitable for ABG testing because citrate acts as an anticoagulant in coagulation studies and would alter the blood’s pH and gas values, invalidating the results.