Venipuncture Site Selection
What is the most common site for adult venipuncture?
The median cubital vein in the antecubital fossa.
What tube color is drawn first in the standard order of draw
Yellow (SPS) or blood cultures
What finger is most appropriate for adult capillary puncture?
The lateral side of the middle or ring finger.
What should you do if a patient faints during venipuncture?
Stop the procedure, ensure patient safety, and notify medical staff
A CCMA is drawing blood for a CBC, PT/INR, and a basic metabolic panel. They collect the lavender top tube first, followed by the light blue, and finally the gold tube. What error was made, and how could it impact the results?
Answer: The order of draw was incorrect; the lavender (EDTA) tube should have been drawn last.
Rationale: Drawing the EDTA tube first can contaminate subsequent tubes, especially the light blue (sodium citrate), potentially skewing coagulation test results like PT/INR. The correct order: light blue, gold (SST), then lavender.
Why might you avoid drawing from a patient’s arm with an IV?
IV fluids can dilute the blood sample and affect test accuracy.
Why is the order of draw important in phlebotomy?
To prevent cross-contamination of tube additives that can alter lab results
What is the heel stick method commonly used for?
Collecting blood from infants, especially newborns
How do you verify a patient’s identity before blood collection?
Ask for full name and date of birth, and cross-check with the ID band and requisition form
A CCMA enters a hospital room and asks the patient, “Are you John Smith?” The patient nods. The CCMA proceeds to collect the specimen. Later, it is discovered the wrong patient was drawn. What step was missed?
Answer: Proper patient identification using two identifiers was not performed.
Rationale: NHA standards require active identification using the patient's full name and date of birth, confirmed with the ID band and requisition. Passive ID methods (like asking yes/no) are not acceptable.
Name two alternatives if the antecubital vein is not accessible.
Dorsal hand veins and forearm veins.
What is the correct order of draw for PT, BMP, and CBC?
Light blue (PT), gold or red (BMP), lavender (CBC).
Why might a capillary puncture be preferred over venipuncture?
It's less invasive and requires a smaller blood volume, ideal for pediatric or geriatric patients
What is an essential post-venipuncture step to prevent bleeding?
Apply pressure to the puncture site and cover it with gauze or a bandage
A patient becomes pale and begins to lose consciousness after a venipuncture. What is the immediate first action the CCMA should take?
Answer: Stop the venipuncture, lower the patient’s head or have them lie down, and stay with them.
Rationale: This is likely a vasovagal reaction. The CCMA must protect the patient from falling, ensure safety, and alert a licensed professional if symptoms worsen.
How does patient age affect venipuncture site selection?
Infants may need heel sticks or scalp veins; elderly patients may have fragile veins requiring gentler handling
What additive is in a lavender top tube?
EDTA, an anticoagulant
What can cause hemolysis in a capillary blood sample?
Squeezing the puncture site too hard or improper technique
Why is hand hygiene necessary before and after phlebotomy procedures?
It reduces the risk of infection for both the patient and the healthcare provider
A CCMA performs a capillary puncture on an adult using the index finger. After collecting the sample, the lab rejects it due to hemolysis. What were two possible errors?
Answer: (1) Using the index finger (incorrect site), and (2) excessive squeezing of the site.
Rationale: The middle or ring finger should be used. Squeezing the site can cause tissue fluid contamination and hemolysis, compromising test accuracy.
What condition makes hand veins preferable for venipuncture?
When antecubital veins are inaccessible due to scarring, obesity, or IV lines
What can happen if the order of draw is not followed correctly?
Test results may be inaccurate due to additive interference.
What must be verified on the requisition form before collecting a specimen?
Patient demographics, test(s) ordered, provider name, and collection date/time
What should be done if a patient has an allergic reaction after the procedure?
Stop all activity, assess the patient, and notify medical personnel immediately
After drawing blood from a patient, a CCMA leaves the room to label the specimen tubes. Another staff member questions this action. What is the issue?
Answer: Specimen tubes must be labeled immediately at the bedside/in front of the patient.
Rationale: Labeling later increases the risk of misidentification, a leading cause of laboratory errors. The NHA expects the label to include the patient’s full name, DOB, date/time, and phlebotomist initials, placed while still with the patient.