Phlebotomy Ch 6 & 7 Flashcards
What is hemostasis?
Arrest or stoppage of bleeding after injury by the body.
Detailed coordinated interaction of endothelial cells lining blood vessels, platelets, other blood cells, plasma proteins and clotting factors.
True or False. Hemostasis is an ongoing occurrence in our body inconjunction with vessel repair.
True
What are the four process steps of Hemostasis?
- Vasoconstriction
- Formation of a primary platelet plug
- Progression to a stable blood clot
- Fibrinolysis (dissolving of clot)
What is serum?
Fluid portion of blood remaining after clotting.
Can be separated from clot by centrifugation.
Does not contain fibrinogen (used up by clotting).
What is plasma?
Fluid portion of blood separated from RBCs, WBCs, and platelets by centrifugation.
Contains fibrinogen.
Specimen must be collected in an anticoagulant tube.
When is plasma used for testing?
Used when serum cannot be used.
What colour is serum?
Pale clear yellow colour fluid.
What are some general equipment (furniture) and their features for phlebotomy?
Blood-Drawing Station - Table for supplies - Special chair - Bed or reclining chair Phlebotomy Chairs - Comfortable - Adjustable armrests - Protect patient from falling injury in case they faint (syncope) Phlebotomy Carts and Trays
What are the concerns regarding phlebotomy carts? Are they brought into patients rooms? Main purpose.
They are large, cumbersome and have a potential to harbor nosocomial infections – for that reason would never be brought into patients rooms
Used for morning routine “sweeps” on wards
Name as many phlebotomy supplies as you can.
Gloves Antiseptic Hand Sanitizer Gauze pads Bandages Pen Patient ID equipment Sharps container Biohazard Bag Tourniquet Needle – various sizes Tube Holder ETS Tubes
What are syringe tubes used for?
Alternative for patients with small or difficult veins
What are some features of syringe needles (length, sheathing, types)?
Syringe needles 1- to 1.5-in long Must have re-sheathing feature (safety cover) if used to draw blood Syringes - Barrel - Plunger
How do you draw blood into a tube with a syringe? What is the advantage of this?
When drawing venous blood by syringe, the phlebotomist slowly pulls back the plunger, creating a vacuum which causes the barrel to fill with blood
This technique takes a bit more manual dexterity.
For fragile veins, this allows you to control the vacuum and be more gentle on small frail veins.
How do you transfer blood into tubes after using a syringe? Is this time sensitive?
Syringe transfer device allows safe transfer of blood into tubes without using syringe needle or removing tube stopper
Since the syringes used for collection do not contain additives blood must immediately transferred into ETS tubes before it starts to clot.
What the main steps when using a syringe needle for blood draw after withdrawal of needle from patient?
STEPS:
- Complete the syringe draw and immediately activate the needle safety device
- Remove the needle
- Discard into sharps container
- Attach a transfer device to the hub of the syringe
- Follow order of draw
- Place ETS tube inside transfer device (we will use a tube rack shown in the video)
- Advance tube onto the needle until blood is drawn into the tube
What are winged infusion set used for?
Winged Infusion Set
Commonly referred to as a butterfly
Effective for small or difficult veins (hands; elderly & pediatric)
What ranges of needle lengths are used on winged infusion sets and why?
Winged infusion sets have a 0.5 to 0.75inch stainless steel needle connected to 5-12 inch tubing
The short needle is important for a smaller angle of insertion needed for difficult or small veins
Comes in various gauges
Some have a 25 gauge needle – remember that small gauge needles will increase chance of hemolysis
Trained professionals may want to use a 25 gauge needle for scalp veins of an infant or tiny veins of premature infants or neonates
What is a nonwinged blood collection set?
Nonwinged Blood Collection Set
VANISHPOINT: Automated in-vein retraction after blood collection to eliminate exposure to the contaminated needle. Depress retraction trigger to retract needle from vein into device.
What are the different safety devices on winged infusion sets?
Textbook:
- Locking shields that slide over the needle,
- Blunting devices
- Needle retracting devices.
Powerpoint:
1. The wings and a plastic sleeve moves over
2. Two plastic pieces separate to move the wings over the needle.
What is a combination system and some of their options?
- Complete system for blood collection; Blood collection tube & collection apparatus are combined in single unit
- Specimen can be collected by evacuated tube or syringe
- Available with regular or butterfly-style needles
- Safety devices are available
What is a limitation of the combination system?
Would only be used if only need one specific tube – no substitution or combining of tubes with different additives is allowed with this system
What are anticoagulants?
Substances that prevent blood from clotting.
Two methods of preventing clotting:
1. Precipitating calcium
2. Inhibiting formation of thrombin
They either bind calcium or precipitating calcium so it is unavailable to the coagulation process OR by inhibiting the formation of thrombin needed to convert fibrinogen to fibrin
What are different types of anticoagulants?
Types: Ethylenediaminetetraacetic acid (EDTA) Citrates Heparin Oxalates
What must be done after collecting a blood tube with anticoagulant for specimen integrity?
Must be mixed ASAP to prevent microclot formation – gentle mixing essential to prevent hemolysis.
Typically for Hematology whole blood specimens are on a constant mixing device to keep the samples continuously mixed or the cells will settle to the bottom of the tube.
How does EDTA prevent clots?
REMOVES calcium by binding it making it unavailable for the clotting process and forms an insoluble salt