unit 7 part 1

              Unit 7 part 1

Standard Guidelines
• The guidelines used in labs across North America is CLSI: Clinical and
Laboratory Standards Institute
• CLSI gives standards for every aspect of the lab from collection to test
methodology, reporting, quality control, etc.
• These change with time, ensure your lab always has the current
edition to refer to
• GP41: Collection of Diagnostic Venous Blood Specimens, 7 th Ed.
(2017) is the most current edition for venipuncture
• These are the best practices – bring them out into industry with you!

Two main circulatory systems - Review
• SYSTEMIC: oxygenated blood
moves from heart to tissues and
brings deoxygenated blood back
to heart
• PULMONARY: lungs receive
deoxygenated blood from heart,
replenishing the oxygen and
sending back to the heart
Image courtesy of SAIT MLA/MLT program

Pathway of Blood
Rt Atrium-
veins return
deoxygenated
blood
Blood enters
the rt ventricle-
pumped thru
pulmonary
arteries to lung
Oxygenated
blood returns to
heart via
pulmonary veins
and empties to
the left atrium
Where it is pumped
to the body via
aortic artery
Blood is
pumped to
left ventricle
Photo courtesy of SAIT MLA/MLT program

& Platelets
<1% of total blood
RBC
Serum
Coagulation factors
(i.e., fibrinogen and more)
consumed in the clot
Whole
Blood
Centrifuged
Blood
Whole
Blood
Centrifuged
Blood
Clot
55% of total
blood
45% of total
blood
No Anticoagulant

Chairs and Beds - outpatient
• Chairs and beds should be made of a material that are easily cleaned and
sturdy
CHAIRS:
• Should be adjustable so minimal bending is required for venipuncture
• Arm rest that comes in front of patient, some are adjustable and
removable to access patient in case of fainting
• Ensure collection chair does not have wheels
BEDS:
• Have a reclining collection chair or bed available for patients with a history
of fainting (syncope)
• Some beds may have wheels, ensure they are locked prior to collection

Hospital Beds - inpatient


• To access patient you may
have to lower the side rails of
the bed
• Ask staff for assistance if
needed
• Ensure you put the bed rails
back up when you are
finished your collection

Phlebotomy Trays - inpatient
• Clean daily, weekly, immediately
• Garbage – sharps and non-sharps
• Stocked
• Not for non-blood specimens
• Do not place on patient surfaces (e.g.,
beds, tables) unless the surface is
protected from contact with the tray
(e.g., disposable pad) - CLSI

Phlebotomy Carts - inpatient
Benefits?
• No need to place tray on patient’s table
• There is a writing surface
• Carry more supplies
• Ergonomic-no need to carry a try
• NOTE: Don’t touch your tray or cart after
you have touched the patient – wash
your hands first
Photo courtesy of MLA/MLT program

Cleaning Phlebotomy Trays/Carts
Daily
• Removal of blood splashes
• Large spills-soak in strong bleach solution for 10 min
Weekly
• Weak bleach bath for 5-10 min
• Followed by soap and water scrub
• Yes, even the pens get wiped down!

Restocking Supplies

• Always leave things ready for the person working after you – leave
things better than how you found it!
• Ensure you check expiry dates of supplies each time you restock
• It is difficult when you are on collection rounds on the ward and you
don’t have the phlebotomy supply required to do the collection
• Let someone know if the supply inventory is getting low
• Must be done each time you use a tray/cart or station

A Clean Tray/Cart
• What does your
tray say about
you?
• About your lab?
• Remember, you
are the face of the
lab!

Sharps Containers
• Will be a puncture-resistant disposal container
• Colour is dependent on your region (yellow or red)
• Will have a biohazard symbol and a fill line
• Do NOT fill above the fill line – once filled, close
and lock (why does it lock?)
• NEVER try to retrieve anything from the sharps
container
• Sharps containers are picked up for proper disposal
by dedicated companies

Gloves
• Provide a protective barrier between patient and
phlebotomist
• Reduces transmission of microorganisms from patient to
patient
• Reduces amount of inoculum if needlestick injury occurs
• CSMLS Laboratory Safety Guidelines, 8 th edition states 46-86%
• There is no excuse for not wearing gloves when collecting blood!!!!

Glove Information
• Not sterile
• Fit well/tight at the wrist
• Free of perforations
• Not easily torn
• Types include: latex, vinyl and nitrile (latex
is not as common anymore due to
sensitivies

Tourniquet Types
1. Blood pressure cuff (pressure <diastolic)
2. Buckle cloth-elastic tourniquet: easy to use (seatbelt), ↑ cost
3. Velcro
4. Non-latex (reduce sensitives/allergies) disposable

Site Disinfectant (Routine)
70% isopropyl alcohol
• Use friction to cleanse around the needle
insertion site
•Allow to air dry before venipuncture (30-60s)
•If site is touched prior to venipuncture, must be
cleaned again
•May re-touch with a gloved finger if the glove
finger has been cleaned with 70% isopropyl
alcohol

Site Disinfectant (Blood Culture)
• 70 % isopropyl alcohol followed by
10% povidone iodine or
chlorhexidine gluconate
• Povidone iodine (Betadine) is not
recommended for routine
venipuncture as it may cause false
increase in:
• K+
• Phos
• Uric acid

Site Disinfectant (Blood Alcohol)
• Non-alcohol based cleanser
• Chlorhexidine gluconate
• Hand washing soap in the lab is often
composed of chlorhexidine gluconate

Gauze/Cotton Balls
• Gauze recommended by CLSI, but
cotton balls are less expensive
• Cotton balls can sometimes attach
to forming clot and when pulled
away remove the new clot
• Apply gentle pressure to stop
bleeding
• Recheck puncture and cover to
protect with clean piece

Tape / Bandages
• Tape and/or bandages are used to
hold gauze in place following
venipuncture and after the site
has stopped bleeding
•Hypoallergenic tape is available for
patients with sensitivitie

Gauge of Needles
• Varying gauges that are colour coded
• The larger the gauge number, the smaller the diameter of the shaft of
the needle
• The smaller the gauge number, the larger the diameter of the shaft of
the needle
• Common ones used for venipuncture:
• 21 Gauge (green)
• 22 Gauge (black)
• 23 Gauge (blue) – pediatrics or small veins
Used for adults

Tube Holder
• Holders can come separate and you assemble the needle OR can
come pre-attached to the needle in one sterile packaging
• Are also considered one-use for collections

Where does the tube go?
• The tube is pushed onto the gray
coloured multisampling needle in
the holder.
• The needle goes into the
Hemogard™ (BD) rubber stopper
recessed in the plastic shield to
access the inside of the tube

All tube stoppers are colour coded to indicate additive (or lack of additive) –
always read label to make sure you have the correct tube.
Conventional stopper
Made entirely of Rubber

Why Colour Coded?
• Tests can only be performed on samples that contain specific additives
(PT/INR –Na Citrate)
• Order of draw is extremely important to prevent carryover
• Color code makes it easier to follow order of draw

Serum Tubes (non-additive tubes)
• Red Top Tubes are glass or plastic and yield
serum
• Glass red topped tubes contain no clot
activators or other additives
• Plastic red topped tubes contain a clot
activator (silica particulates) – more
commonly used
• Allow to clot for 60 minutes before
centrifuging (LifeLabs Ontario) based on BD
package insert
• No gel separator in this coloured tube –
serum must be separated from cells within 2
hours

Additive Tubes – Serum or Plasma
Additive-any substance placed inside a tube other than the silicone
coating of the tube or tube stopper
•Separation devices (gel)
•Clot activators
•Anticoagulants
•Cell preservatives
•Tubes may contain one or more additive, in various combinations

Thixotropic Gel Separators
• Form a physical barrier between clot/cells and serum/plasma
• Inert material – does not interfere with test
• SST – Serum Separating Tube / PST – Plasma Separating Tube
Remember:
• Glucose values will decrease if cells are left on serum/plasma (5-7%
per hour)
• K+ levels will increase as K+ leaves cells into plasma
• The gel separates the serum from the cells, so no need to
aliquot/separate

Serum Tubes with Clot Activators
• Initiate or enhance clot formation:
• Provides increased surface area for
platelet activation (glass/silica beads,
clays)
• Enhance clotting process
(thromboplastin and thrombin)
• 5 minutes to clot vs 30-60 minutes
Rapid Serum Tube (Thrombin)

Serum Tubes (with gel)
• SST – Serum Separating Tube
• Commonly used for Chemistry tests
• Once collected, allow to sit and clot for
30 minutes before centrifugation
according to BD product insert
• The gel separates the formed clot and
the serum, so no need to
aliquot/separate for testing
• Comes in various sizes

SST allowed to clot then spun; gel moves to
separate clot and serum
Photo Courtesy of MLA/MLT program

Anticoagulants
• EDTA
• Heparin
oammonium/lithium/sodium
• Sodium citrate
• Oxalates
opotassium/ammonium
Hematology
Chemistry
Coagulation
Chemistry
Tubes are called sometimes by their anticoagulant or by their colour – these are
interchangeable

EDTA (Lavender top tube)
Ethylenediaminetetraacetic acid
Or
Ethylenediaminetetraaceticacid
How Does it Work?
• Chelates calcium
• Inhibits platelet clumping
• Preserves cell integrity

EDTA
• Used for CBC – complete blood count in( two type EDTA)
Hematology (4 mL)
• Can also be used for T&S testing in
Transfusion Medicine (2 x 6 mL tubes)
• Cannot be used for coagulation studies
• Interferes with factor V and activation of
fibrinogen by thrombin

Two types of EDTA-not in your notes
• K 2EDTA
§International Council for
Standardization in Hematology
suggests K 2EDTA
• K 3EDTA(it cose cell srinke)
§can cause cells to shrink=lower
MCV and HCT
§Slight dilution factor as K 3EDTA is a
liquid (1-2%)

Heparins (green top tube) - PST
• If gel present, called a PST –
plasma separating tube
• Sodium Heparin, Lithium Heparin,
Ammonium Heparin
• Inhibit coagulation by interfering
with thrombin formation (required
for clotting)
• Used often in Chemistry for STATs
as it does NOT need to sit and clot
before centrifugation

Na Citrate (light blue top tube)
• Binds calcium to prevent clotting
• Used in coagulation testing (PT,
PTT, etc.)
• Must be filled for testing, so if
hard draw, opt for the smaller
tube (1.8 mL)

2.7 mL draw 1.8 mL draw
Both 13 mm x 75 mm tube

Na Citrate Volume Requirement
• Important tubes are at least 90% full
• If short draw, MLT will reject at the bench as this will falsely affect the
patient’s coagulation results – could impact dosage of medication
(anticoagulants like Heparin or Coumadin) if false result goes to
physician
• Blood: anticoagulant ratio is 9:1
• 9 mL blood to 1 mL anticoagulant
• 4.5 mL blood and 0.5 mL anticoagulant

Special Rules for Na Citrate
Discard tube required if:
• Special coagulation-factor VIII
• Butterfly needle used (air in tubing will displace blood in
the tube)
Throw away the discard tube, it is not needed for testing.

Coagulation Testing
What happens to a
PT/INR and/or PTT
result if Tube 2 is
used?
Falsely
prolonged
result

Oxalate (Gray top tube) sodium floride and potassium oxilate in gray tube maintain plasma glucose level
• Potassium or ammonium
• Binds calcium
• Usually used in conjunction with antiglycolytic agents

Antiglycolytic Agents
• Additives that acts as cell
preservatives
• Inhibit the metabolism of glucose by
cells in the blood sample
• Sodium fluoride-inactivates enzymes
required for glucose metabolism in
Gray top tube

Why collect in a sodium fluoride tube instead
of heparin for glucose?
• Glucose obtained from unprocessed blood samples can decrease by
5%–7% per hour due to glycolysis
• If sample is not going to be spun and/or separated right away collect
in Na Fluoride
§ Na Fluoride inactivates the enzyme systems that are required for glucose
metabolism

Size of Tubes
• The size of the tube is indicated on the label
• Just because they are the same size, does not
mean the same volume will be drawn
• There are smaller and larger tubes depending on
the quality of the vein
• If you feel it will be a difficult collection, collect
with the smaller tube to ensure the
anticoagulant:blood ratio is more accurate Typically come in 4 and 6 mL
EDTA tubes

Blood : Additive Ratio
• According to CLSI, the actual draw (by the vacuum) must be +/- 10%
of the labelled volume
Example:
• 5.0 mL tube
• 4.5 – 5.5 mL

Points to Remember
• Follow correct order of draw
• Fill tubes to correct capacity
• Mix immediately and accurately
• Do not pour two partially filled tubes together
• Do not remove additive from tube
• Label tubes properly at (patient bedside)
• Transport samples properly
• Perform correct pre-analytical procedures (let samples clot prior to centrifuging)