Phlebotomy Ch. 8: Lecture 1
Equipment
carry equipment in a tray or cart to draw blood on inpatients
never put tray on bed
Tourniquet
most common way to locate a vein
prevents venous blood blow and causes veins to bulge
may be latex or non-latex
may be used only once and disposed of or cleaned before use on another pt
Puncture site
use 70% alcohol
if pt is allergic use iodine, chlorhexidine gluconate, or benzalkonium chloride
use 2 in by 2 in gauze square to apply pressure to the puncture site after remove needle and clean
Needles
have point, bevel, and shaft
shaft
can differ in length and gauge
gauge
describes diameter or lumen of the needle
the higher the gauge number, the smaller the lumen of needle
choose correct gauge based on the patients veins
adults 20-21
children or adults with smaller with small veins 22,23
Mutisample needles
double ended with one tip used on patients arm and second end used to pierce tube stopper
have a retractable rubber sleeve that covers second tip when tubes are changed to prevent blood from leaking into holder.
Syringe needles
has a plunger, a barrel, and syringe needle
used on small, fragile veins to control the pull on vacuum on the veins
in hospitals they never use syringes or butterfly needles
pull the needle slow because if you do it too fast it can break an artery
you will see a flash of blood in the hub of needle when your in a vein
blood must be transferred to evacuated tubes
Winged or Butterfly needles
used on pediatric or elderly patients for small veins, such as in the hand
has a 1/2 to 3/4 in, 23 gauge needle with wings and plastic tubing
syringe or tube holder can be attached at the end
very expensive and not used on anticubital
Evacuated tube system
uses multisample needle, evacuated tube, and adapter
needle holder is used once and then disposed into the sharps container
use all materials from the same manufacturer for fit or results
collection tubes
the tubes are color coded and can be different shapes
tube size depends on pt, vein size, and amount of blood needed
can be either plastic or gas
each tube has an additive or chemical
chemical added to prevent or promote changes in sample
Blood specimens
Whole blood
mixed with anticoagulant to prevent clotting and is for hematology cell counts
Serum
remaining fluid portion of blood after clotting; used for chemical testing
Plasma
fluid portion of blood containing an anticoagulant; used for stat chemical testing
Tube additives
any tube with additives must be inverted 5-8 times
identified by the stopper color
tubes are coated with silicone to prevent blood from sticking to the sides
the only tube that doesn't add additives are the red glass tubes
Anticoagulants
they prevent blood from clotting
the choice of one varies with the test being done
example: EDTA, citrate, oxalate all bind calcium
Example: Heparin inhibits conversion of prothrombin to thrombin
Antiglycolytic Agents
sodium fluoride
additive in a gray stopper tube used for glucose
it also inhibits glycolysis or metabolism of glucose for accurate testing
lithium iodoacetate
an acceptable alternative used for gray stopper tube for glucose testing
Clot Activators
Thrombin
additive that promotes coagulation
blood will clot with in 5 minutes
Glass/silica
promotes clotting by providing more surface area for platelets to activate
silica particles cause blood to clot within 15-20 minutes
Tubes with clot activators must be inverted, turned, to allow blood to come into contact with activator
Thixotropic Gel
inert, synthetic substance with a density between cells and plasma or serum and looks like snot
When a blood tube with gel is centrifuged, spun at high speed, the gel becomes a liquid
Forms a layer upon hardening between cellular and liquid layer
Ex: SST or serum separation tube