Phlebotomy-Technician Exam Questions & Answers

Burned skin should be avoided for venipuncture because the tissue barrier is compromised and the site carries an increased risk of infection. A venipuncture intentionally breaches the skin, so selecting tissue that is already injured, inflamed, fragile, or poorly healed increases the chance of introducing microorganisms and worsening local tissue damage. Burned areas can also have altered circulation, scarring, tenderness, edema, and impaired healing, making vein assessment and needle control less reliable. Although damaged skin elasticity can make puncture technically difficult, the best clinical reason in this item is infection risk. Inaccuracy of laboratory results is more directly associated with sites such as IV arms, edematous tissue, hematomas, or improperly handled specimens. Vein sclerosis is associated with repeated venipuncture, medication irritation, or diseased veins, not simply the use of burned skin. The NHA CPT test plan includes venipuncture site selection, contraindicated collection sites, infection control, and patient safety under routine blood collection and safety competencies. Reference topics: Routine Blood Collections; Safety and Compliance; site selection; infection prevention.

When there is a risk of blood splatter, the phlebotomist should wear eye and face protection, such as a face shield or goggles with a mask. Standard gloves protect the hands but do not protect the mucous membranes of the eyes, nose, and mouth. Sterile gloves are not routinely required for standard venipuncture; clean gloves are typically used unless a sterile procedure is specified. Shoe covers are not the primary protection for facial splash exposure. An N95 respirator protects against airborne particles but does not replace splash protection unless combined with appropriate eye and face protection when needed. The correct PPE is based on anticipated exposure. A routine venipuncture may require gloves only, but procedures with splash risk require additional barriers. The phlebotomist must evaluate the procedure, patient behavior, specimen type, and environment before collection. PPE use also includes proper donning, removal, disposal, and hand hygiene after glove removal. Reference topics: Safety and Compliance; PPE selection; standard precautions; splash exposure; mucous membrane protection.

A clotted lavender-top specimen is a reason for specimen rejection. Lavender-top tubes contain EDTA anticoagulant and are used for tests such as CBCs, which require anticoagulated whole blood. If the specimen clots, the cellular components are trapped in the clot, platelet counts can be falsely low, and automated hematology analysis becomes unreliable. Properly labeled specimens, correctly filled light-blue tubes, and specimens transported upright are acceptable practices, not rejection causes. A clotted lavender specimen usually results from failure to mix the tube properly immediately after collection, delayed inversion, underfilling or collection difficulty, or drawing blood slowly and allowing clotting to begin before the specimen contacts the additive. The correct prevention is to fill the tube to the required volume and gently invert it the recommended number of times immediately after collection. The phlebotomist should never shake the tube, because vigorous agitation can cause hemolysis. Reference topics: Processing Specimens; specimen rejection; EDTA tube mixing; clotted specimens; hematology testing.

Using a needle with a gauge that is too small can cause hemolysis. A small-bore needle can create excessive mechanical force as blood passes through the lumen, damaging red blood cells and releasing intracellular contents into serum or plasma. Hemolysis can alter test results, especially potassium, lactate dehydrogenase, and other analytes affected by red-cell rupture. Allowing alcohol to dry before puncture is correct practice because it reduces stinging and helps prevent contamination. Releasing the tourniquet before needle removal is also correct because it reduces pressure and supports safer needle withdrawal. Mixing additive tubes by gentle inversion is required; the danger occurs when tubes are shaken vigorously. Additional hemolysis causes include probing, drawing through a hematoma, forcing blood from a syringe into a tube, rough transport, incorrect centrifugation, and delayed processing. A phlebotomist must choose equipment appropriate to the patient's vein while maintaining specimen quality. Reference topics: Routine Blood Collections; hemolysis; needle gauge selection; specimen integrity; preanalytical error.

The vein is anchored by placing the thumb of the free hand below the intended puncture site and gently pulling the skin taut. This stabilizes the vein, reduces rolling, creates a firmer puncture surface, and supports accurate needle entry. Anchoring above the site is unsafe because it places the phlebotomist's hand in the direction of needle travel and increases needlestick risk. Using two fingers instead of the thumb provides less controlled traction and may interfere with the venipuncture angle or contaminate the prepared site. The phlebotomist should avoid touching the cleansed puncture site after antisepsis unless the site is re-cleansed. Proper anchoring is especially important for superficial or mobile veins because failure to stabilize the vein can cause missed access, hematoma formation, probing, patient discomfort, or specimen collection failure. The NHA CPT outline identifies anchoring the vein below the venipuncture site and knowledge of anchoring techniques as routine venipuncture competencies. Reference topics: Routine Blood Collections; site selection; anchoring below venipuncture site; venous anatomy and safe insertion technique.