Which equipment is essential to prevent sample contamination and maintain ABG integrity during collection?

• A. Heparinized syringe
• B. Plain glass syringe
• C. EDTA tube
• D. Citrate tube

Answer: (A)

The essential idea is that arterial blood gas samples must be kept free from clotting and from additives that would alter the gas measurements. A heparinized syringe provides the necessary anticoagulant, preventing clot formation that can trap blood elements and change gas tensions, while not significantly distorting pH or PaCO2. Using a plain glass syringe risks clotting, which can invalidate the sample. Additives in EDTA or citrate tubes would introduce chemicals that bind calcium or otherwise interfere with acid–base balance and gas solubility, contaminating the ABG results. So, a heparinized syringe is the best choice to maintain ABG integrity and minimize contamination.