Equipment Essentials
What is the primary purpose of a tourniquet in phlebotomy?
To impede venous blood flow and make veins more prominent.
What is the first tube typically collected in the standard order of draw?
Blood culture tubes (yellow-top or bottles)
What is the name of the vein most commonly used for venipuncture in the antecubital fossa?
Median cubital vein.
What is the most common complication associated with venipuncture?
Hematoma.
What additive is found in a lavender-top tube, and what type of test is it commonly used for?
EDTA (ethylenediaminetetraacetic acid), and it's commonly used for complete blood counts (CBCs).
What color tube top indicates a tube containing EDTA as an anticoagulant?
Lavender or Purple.
After blood cultures, what color tube is typically collected next in the order of draw?
Light blue-top tube (sodium citrate)
What is the difference between arteries and veins in terms of blood flow?
Arteries carry oxygenated blood away from the heart, while veins carry deoxygenated blood back to the heart (with the exception of the pulmonary artery and vein).
What is the first action a phlebotomist should take if a patient experiences syncope during a blood draw?
Remove the needle and ensure the patient's safety (e.g., lower them to the ground or chair).
What is the purpose of the clot activator in a red-top or gold-top tube?
To accelerate the clotting process, allowing for serum separation.
Describe the gauge of needle most commonly used for routine adult venipuncture, and explain why.
21 or 22 gauge. It is a good balance between minimizing patient discomfort and preventing hemolysis.
Why is it crucial to follow the correct order of draw?
To prevent contamination of additives from one tube to another, which can affect test results.
What are the three layers of a vein wall?
Tunica adventitia (outer), tunica media (middle), and tunica intima (inner).
What are standard precautions, and why are they important in phlebotomy?
Standard precautions are infection control practices used to prevent the transmission of bloodborne pathogens. They include hand hygiene, use of personal protective equipment (PPE), and safe handling of sharps.
What additive is in a light-blue-top tube, and what type of test is it used for?
Sodium citrate, and it is used for coagulation studies (e.g., PT, PTT, INR).
What is the function of the tube holder (adapter) in a vacuum tube system?
It holds the needle and the vacuum tube, providing a secure connection.
In what order are serum tubes (red or gold), light blue tubes, and EDTA tubes (lavender) drawn in relation to green top tubes?
Light blue, serum tubes (red or gold), green, and then EDTA tubes (lavender).
What is the function of red blood cells (erythrocytes)?
To transport oxygen throughout the body.
How can a phlebotomist minimize the risk of nerve damage during venipuncture?
By avoiding probing or excessive redirection of the needle, and by carefully selecting venipuncture sites.
What is the function of the gel separator in a serum separator tube (SST or gold top)?
To create a barrier between the serum and the red blood cells after centrifugation.
Explain the difference between a winged infusion set (butterfly needle) and a standard straight needle, and when each is typically used.
If a patient requires a light-blue, a red, a green, a lavender, a gray and a yellow (SPS) top tube, what is the correct order of collection?
Yellow (SPS), light-blue, red, green, lavender, gray.
Explain the physiological reasons why veins are preferred over arteries for routine venipuncture, and describe the potential complications associated with arterial puncture.
Describe the procedure for handling a needlestick injury, including the steps for reporting and follow-up.
Describe the purpose of the sodium fluoride and potassium oxalate additives found in a gray-top tube, and what common tests are performed using this tube?
Sodium fluoride inhibits glycolysis (the breakdown of glucose), and potassium oxalate acts as an anticoagulant. This tube is commonly used for glucose testing and lactate measurements.