blood collection equipment, additives and order-of-draw

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BLOOD COLLECTION EQUIPMENT, ADDITIVES AND ORDER-OF-DRAW
Blood
 Is a specialized body fluid that delivers necessary substances to body’s cells
 5 – 6 liters or 7 – 8% of the TBW (in an adult)
 Composition:
 45% is composed of formed elements, red blood cells (RBC), white blood cells
(WBC), and platelets (plt)
 55% is the fluid portion
o 90% is water and 10% composed of CHON, CHO, vitamins, hormones,
enzymes, lipids, and salts
o Plasma
 Liquid portion of blood when coagulation is prevented by the use
of an anticoagulant
o Serum
 Liquid portion of blood released from the clot
VENIPUNCTURE
 The process of collecting or “drawing” blood from a vein
Equipment
1. Antiseptics
 Are substances used to prevent sepsis, the presence of microorganisms or their
toxic products in the bloodstream
 Antiseptics used in blood collection
o 70% ethyl alcohol
o 70% isopropyl alcohol
o Benzalkonium chloride (Zephiran chloride)
o Chlorhexidine gluconate
o Hydrogen peroxide
o Providone-iodine (0.1 – 1%)
o Tincture of iodine
2. Sterile gauze pads
 Are used to hold pressure over the site following blood collection procedures
3. Tourniquet
 Is a device applied or tied around a patient’s arm prior to venipuncture
 Vein-locating devices
o Transillumination devices such as Venoscope II
o Vein Entry Indicator Device (VEID)
4. Needles
 Multisampling needles
 Hypodermic needles
 Winged infusion (butterfly) needles
 Are designated by gauge number
o Needle gauges w/ needle type & their use
Gauge
Needle type
Use
15 – 17
attached to collection bag
collection of donor
units
18
syringe
transfer needle
Gauge
20
21

Needle type
multisample syringe
multisample syringe
22
multisample syringe
23
butterfly
Length of the needle
o Multisample & syringe come in 1-inch to 1.5-inch
o Butterfly have ½ to ¾ inch
Use
w/ normal sized veins
standard
venipuncture needle
px w/ difficult veins
pediatric veins
5. Evacuated Tube System (ETS)
 A closed system in which the patient’s blood flows through a needle inserted
into a vein, directly into a collection tube
 3 basic components:
o A special blood-drawing needle
o A needle and a tube holder
o Various types of evacuated tube
6. Syringe System
 Used for patients with small or difficult veins
7. Bandages
 Used to cover a blood collection site after the bleeding has stopped
8. Anticoagulants
 Are substances that prevent blood from clotting by either two (2) methods:
o Removal of Calcium
 Chelation
 Precipitation
o Inhibiting the formation of thrombin
 EDTA (Ethylenediamine tetra-acetic acid)
o Prevents coagulation by chelating calcium
o 3 forms
 Versene (dry or powder form)
 Na2EDTA
 Sequestrene (liquid and spray dried form)
 K2EDTA  spray dried form
 K3EDTA  liquid form
o Optimal concentration is 1.5 mg/mL of blood
o Advantages:
 Preserves cellular morphology
 Prevents platelet clumping and artifact formation
o Disadvantages:
 Excessive EDTA causes cells to shrink
 Not satisfactory for coagulation studies
o EDTA is contained in
 Lavender top tubes
 Microcontainers w/ lavender tops
 Pink plastic-top tubes
 Royal blue top tubes
 White top tubes



Citrates (Sodium Citrate)
o Prevents coagulation by chelating calcium
o Used routinely for coagulation studies and for platelet aggregation
studies
o Also used to monitor heparin therapy
o 2 concentrations
 3.2% (0.109 M or 0.105 M)
 3.8% (0.129 M)
o The standard ratio of blood to citrate is critical for coagulation test results
to be valid  9:1 ratio
o Advantages:
 Helps stabilized pH
 Used in combination with dextrose (ACD or CPD)
Heparin
o Prevents coagulation by inhibiting the formation of thrombin
o Used primarily for plasma chemistries and potassium determinations
o Optimal concentration is 15 – 30 U/mL of blood
o 3 formulations
 Ammonium heparin
 Lithium heparin
 Sodium heparin
o Advantages:
 Prevents hemolysis
 Less toxic than sodium citrate
o Disadvantages:
 Causes morphologic distortion of platelets and leukocytes
 Produces bluish discoloration in the background of blood films
Oxalates (Potassium oxalate)
o Prevents coagulation by precipitating calcium
o Used for glucose testing and alcohol levels
o Contains antiglycolytic agents such as sodium fluoride and lithium
iodoacetate
Table of Collection Tube Colors and Additives:
Color Stopper
Red (glass)
Red (plastic) or Gold
Lavender (glass)
Lavender (plastic)
White
Royal blue
Green (plastic)
Pink
Light blue
Black
Green
Additive
None
Clot activator/gel
separator
K3EDTA
K2EDTA
EDTA & gel
Na heparin &
Na2EDTA
K2EDTA
K2EDTA
3.2% or 3.8% sodium
citrate
Buffered Na citrate
Sodium heparin
Lithium heparin
Ammonium heparin
Additive function
None
Silica clot activator
Laboratory Use
Chem, Sero, BB
Chem & Sero
Chelates calcium
Chelates calcium
Chelates calcium
Inhibits thrombin &
chelates calcium
Chelates calcium
Chelates calcium
Chelates calcium
Plasma, hema, CBC
Plasma, hema, CBC
Plasma, molecular dx
Plasma, chem.,
toxicology
Plasma, lead testing
Blood banking
Plasma, coagulation
(PT, PTT, factor
assays)
Westergren ESR
Plasma chem.
Chelates calcium
Inhibits thrombin
formation
Green (glass) ; Brown
Sodium heparin
Inhibits thrombin
Plasma, lead testing
Light green
Lithium heparin & gel
Gray
Potassium oxalate w/
Na fluoride & lithium
iodoacetate
Thrombin
Inhibits thrombin
formation
Inhibits glycolysis
Plasma chem.,
potassium levels
Plasma glucose
testing, alcohol levels
Clot activator
STAT chem
Orange
Order of Draw
 The special sequence of tube collection
1. Sterile tube or blood culture tube (yellow)
2. Sodium citrate tube (light blue)
3. Serum tubes w/ or w/out clot activator or gel separator (red)
4. Heparin tube w/ or w/out gel plasma separator (green)
5. EDTA tube (lavender)
6. Glycolytic inhibitor tube (gray)
 Alternate Syringe order of filling evacuated tube
1. Sterile tube or blood culture tube (yellow)
2. Sodium citrate tube (light blue)
3. EDTA tube (lavender)
4. Heparin tube w/ or w/out gel plasma separator (green)
5. Glycolytic inhibitor tube (gray)
6. Serum tubes w/ or w/out clot activator or gel separator (red)
Effect of Anticoagulants/Additives on Various Blood tests/analytes
Additive
EDTA
Oxalate
Citrate
Heparin
Test
Alkaline phosphatase
Creatine kinase
Leucine aminopeptidase
Calcium and iron
PT and APTT
Sodium and potassium
Platelet aggregation
Acid phosphatase
Alkaline phosphatase
Amylase
LDH
Calcium
Sodium and potassium
Cell morphology
ALT, AST
Alkaline phosphatase
Acid phosphatase
Amylase
Calcium
Sodium and potassium
Labile coagulation factors
Triiodothyronine
Thyroxine
PT and APTT
Effect
Inhibits
Decrease
Increase
Prevents
Inhibits
Decrease
Increase
Distorts
Inhibits
Stimulates
Decrease
Increase
Preserves
Increase
Fluorides
Wright’s stain
Lithium (LiHep tubes only)
Sodium (NaHep tubes only)
Acid phosphatase
Alkaline phosphatase
Amylase
Creatine kinase
ALT, AST
Cell morphology
Causes blue background
Increase
Decrease
Distorts
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