NHA Certified Phlebotomy Technician (CPT)Collection RoutineEasy
A phlebotomy technician is preparing to perform a capillary puncture on an adult patient. Which of the following fingers is the most appropriate site for this procedure?
- AIndex finger
- BRing finger
- CThumb
- DPinky finger
Show answer & explanationAnswer & explanation
Correct answer: B. Ring finger
The ring finger (and middle finger) are the preferred sites for adult capillary punctures due to adequate tissue depth, good circulation, and fewer nerve endings compared to the index finger or thumb.
Why the other options are wrong
- A. The index finger is generally avoided due to increased nerve endings and frequent use, which can lead to discomfort and infection.
- C. The thumb is too muscular and has a pulse, making it unsuitable for capillary puncture.
- D. The pinky finger has less tissue and bone is closer to the surface, increasing the risk of injury.
Adult Capillary Puncture Site
For adult capillary punctures, the preferred sites are the palmar surface of the distal phalanx of the middle or ring finger, slightly off-center.
- Middle or ring finger preferred
- Lancet puncture should be slightly off-center
- Avoid index finger, thumb, and pinky finger
- Ensure good circulation by warming the hand if necessary
Memory trick: For adult fingers, 'Middle' and 'Ring' are the golden 'Spots'.