Phlebotomy Equipment, Sterility, and Documentation
Core concepts
Equipment questions test matching device to situation. Evacuated tube systems use a holder, multisample needle, and tubes with predetermined vacuum; they are efficient for adults with good veins. Butterfly (winged) sets suit fragile or small veins and pediatric patients but have a longer tube and are more prone to hemolysis and underfilling. Syringes are used for fragile veins or when vacuum could collapse a vein, then blood is transferred to tubes-transfer gently to avoid hemolysis. Needle gauge is inversely related to number: a 21-gauge is standard for adults; 23-gauge suits small veins. Larger gauges (lower numbers) cause more hemolysis.
Sterility is a chain: cleanse the site with an antiseptic (alcohol or chlorhexidine per policy) in concentric circles, allow it to dry fully, and do not re-palpate the cleansed site with a bare finger. Single-use devices only; check expiration and package integrity. For blood cultures, cleanse with the facility's protocol and disinfect the bottle septum.
Documentation is the legal record. Record date, time, site, number and type of tubes, patient tolerance, and any complications. Label tubes at the bedside, in the patient's presence, with two identifiers. Never pre-label tubes.
Worked example
A fragile elderly vein collapses on vacuum draw. The correct choice is a smaller-volume tube or a syringe/butterfly with controlled draw, not a larger needle. Rule of thumb: when in doubt, the gentler device and the smaller draw protect the specimen and the vein.