Dermal Puncture vs Venipuncture
In some situations, the phlebotomist will make the decision if a blood specimen will be obtained by dermal puncture or venipuncture. The patient's condition, the age of the patient, the amount of blood needed for testing, and the risks associated with the procedure will help the phlebotomist determine the best method for collection.
A dermal puncture requires less precision, therefore it is less critical for the patient to be still or immobilized. However, if the puncture is not performed correctly, or an approved site is not used, the puncture may cause more discomfort, or even injury to the patient.
The risk of accidental needlestick injury to the patient and phlebotomist is minimal since the puncture device is designed to retract the needle once the puncture is made.
The puncture is quick and standardized for puncture depth. However, the procedure takes longer to complete. This delay in collection of the blood specimen could result in hemolysis or clotting of the blood or tissue fluid contamination of the specimen and specimen rejection by the laboratory.
The dermal puncture minimizes the amount of blood taken from the patient. This will be important to consider, especially with infants in an intensive care nursery. However, some laboratory tests require larger amounts of blood for testing; in these cases, capillary collection is not an option.
If a patient is dehydrated or has poor peripheral circulation, an adequate blood collection from a dermal puncture may not be possible.