Phlebotomy Practice Questions

Direct pressure is the best way to stop bleeding from a needle stick because it compresses the vessel right at the wound. Indirect or longitudinal pressure don’t concentrate force on the bleeding site, and tourniquets are reserved for severe arterial bleeds.

ACT (activated clotting time) is used to monitor heparin therapy because it measures how long blood takes to clot under the influence of heparin. SST tubes collect serum, H&H tests measure hemoglobin and hematocrit, and POCT is just a general term for point-of-care tests.

The stratum basale is the deepest layer of the epidermis, sitting directly on the basement membrane. It contains the basal keratinocytes responsible for continuous skin cell renewal. Layers above it include the spinosum, granulosum, and the outermost corneum.

The feather edge of a blood smear is the thin, fringed area where cells lie in a single layer for clear viewing. Other regions of the smear are too thick for detailed cell morphology.

Polycythemia literally means “many cells” and refers to an abnormally high red blood cell mass. Dehiscence, transection, and escharotic conditions are unrelated to red cell production.

The NCCLS recommends a maximum heel puncture depth of 2.0 mm to avoid injuring the calcaneus. Going deeper increases the risk of bone injury and pain. Staying at or below 2.0 mm ensures a safe, adequate blood sample.

PKU tests are most commonly performed on newborns using a heel (skin) puncture, with blood collected on filter paper. This dried blood spot method reliably detects phenylketonuria. Arterial samples or bilirubin/BUN tests are not used for PKU screening.

A butterfly needle is the standard name for a winged infusion set, featuring flexible “wings” that help stabilize the needle during blood draws or IV infusions. “Hub” and “sharps” refer to parts or general hazards, not the winged design.

CPD stands for “citrate phosphate dextrose,” an anticoagulant solution used in blood collection and storage. Citrate chelates calcium to prevent clotting, while phosphate and dextrose preserve red cell viability.

Personal distance ranges from about 1.5 to 4 feet and is used for conversations among friends and acquaintances. Standing three feet away falls squarely within this zone. Social and public distances are greater, while intimate distance is closer than 1.5 feet.