How are air bubbles prevented during sample collection?

• A. Dead space in needle filled with sterile anticoagulant
• B. Cap the needle
• C. Shake vigorously
• D. Leave air in the collection line

Answer: (A)

Preventing air bubbles hinges on occupying the space inside the needle and initial tubing with liquid, not air. Filling the dead space with sterile anticoagulant before drawing blood ensures that when the sample is collected, there is no trapped air to be drawn in. This keeps the sample free of air pockets and maintains proper anticoagulation. Cap the needle, shake vigorously, or leave air in the collection line either doesn’t address the trapped air or actually introduces or preserves air, leading to bubbles.