NHA Certified Phlebotomy Technician (CPT)Collection RoutineHard
A phlebotomy technician is collecting a blood gas specimen. Which of the following is the most important collection consideration for this test?
- AUsing a standard evacuated tube system.
- BCollecting the specimen in a green top tube.
- CEnsuring the specimen is free of air bubbles.
- DAllowing the specimen to clot for 30 minutes.
Show answer & explanationAnswer & explanation
Correct answer: C. Ensuring the specimen is free of air bubbles.
Blood gas specimens (ABGs) measure dissolved gases in the blood. Air bubbles introduced during collection will alter the gas concentrations, leading to inaccurate results, particularly for oxygen and carbon dioxide levels.
Why the other options are wrong
- A. Blood gases are typically collected using an arterial puncture with a specialized syringe, not a standard evacuated tube system for venous draws.
- B. Blood gases are typically collected in special heparinized syringes, not green top tubes, which are for venous plasma chemistry.
- D. Blood gas specimens are collected in heparinized syringes and should not clot; they need to be analyzed immediately or chilled.
Blood Gas Collection Integrity
Accurate blood gas analysis depends on meticulous collection to prevent exposure to room air, which can alter gas concentrations and lead to erroneous results.
- Collected in heparinized syringe.
- Avoid air bubbles.
- Transport on ice and analyze quickly.
Memory trick: Blood Gas: No Air, No Error!