NHA Certified Phlebotomy Technician (CPT)Collection RoutineEasy
A phlebotomy technician is preparing to collect a blood culture. Which of the following is the most critical step in preventing contamination of the specimen?
- AUsing a winged infusion set for collection.
- BPerforming thorough antiseptic skin preparation.
- CCollecting a sufficient volume of blood for each bottle.
- DInoculating the aerobic bottle first.
Show answer & explanationAnswer & explanation
Correct answer: B. Performing thorough antiseptic skin preparation.
Thorough antiseptic skin preparation is the most critical step for blood cultures to eliminate skin flora, which is the primary source of contamination and can lead to false positive results.
Why the other options are wrong
- A. While a winged infusion set can be used, it does not directly prevent contamination more than other methods if skin prep is inadequate.
- C. Collecting sufficient volume is important for pathogen detection but does not prevent contamination from skin flora.
- D. The order of draw for blood culture bottles (aerobic first) is important but secondary to proper skin antisepsis in preventing contamination.
Blood Culture Contamination
Blood cultures are highly susceptible to contamination by skin flora. Preventing this requires meticulous antiseptic technique to ensure accurate diagnostic results.
- False positives lead to unnecessary treatment.
- Skin flora is the main source of contamination.
- Povidone-iodine or chlorhexidine are common antiseptics.
Memory trick: Clean skin, clean blood, clear results!