Specimen Collection Flashcards
7 cards from real Certified Phlebotomy Technician Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Specimen Collection flashcards as text
Which gauge needle is most commonly used for routine venipuncture in adults?
Answer: 21 gauge
A 21-gauge needle is the standard choice for routine adult venipuncture, balancing flow rate and patient comfort.
What is the maximum time a tourniquet should remain applied before venipuncture to avoid hemoconcentration?
Answer: 1 minute
A tourniquet should not be applied for more than 1 minute before puncture to prevent hemoconcentration and altered test results.
Which blood culture collection technique helps prevent contamination?
Answer: Using chlorhexidine or iodine after alcohol and allowing it to dry
Blood culture sites require a two-step antiseptic prep (alcohol followed by chlorhexidine or iodine, fully dried) to minimize contamination.
When collecting capillary blood from a neonate's heel, which area should be avoided?
Answer: Central posterior curvature of the heel
The central posterior curvature of the heel is avoided in neonates because it overlies the calcaneus bone and risks osteomyelitis.
A patient's arm shows petechiae after tourniquet application. What does this indicate?
Answer: Possible coagulation or platelet disorder
Petechiae (small red dots) appearing after tourniquet use suggest a possible coagulation defect or thrombocytopenia.
Which additive is found in a light blue (sodium citrate) tube and why is underfilling critical?
Answer: Sodium citrate; incorrect blood-to-anticoagulant ratio affects coagulation results
Light blue tubes use sodium citrate at a precise 9:1 blood-to-anticoagulant ratio; underfilling dilutes the specimen and falsely prolongs PT/aPTT.
What is the preferred site for venipuncture in an infant under 2 years old?
Answer: Heel capillary stick
Heel capillary puncture (heel stick) is the preferred method for infants under 2 years due to vein size and safety concerns.