Blood Collection, Anticoagulants And Others (including safety) Flashcards
Greek:
Haima = blood
Logos = study
Hematology
Red liquid circulating in the heart, veins (5mm), arteries (4mm and capillaries (8 um)
Blood
Functions of the blood
Respiratory
Nutritional
Excretory
Buffering action
Maintenance of body temperature
Transport of hormones
Defense mechanism
Blood composition: Solid part
Erythrocytes
Leukocytes (Granular - Neutro, Eosi, Baso) (Agranular - Mono, Lympho)
Thrombocytes
Technique to obtain blood from:
Newborns/ Pediatric
Burned px
Px whose veins are reserved for therapeutic purposes
Extremely obese
Elderly px
Skin puncture
Puncture site for infants (< 1 yr old)
Plantar surface (Medial or lateral side)
Puncture site children (>1 yr old) and adults
Palmar surface of non-dominant hand (3rd or 4th finger)
Depth of skin puncture (infants and small children)
< 2 mm
Depth of skin puncture (adults)
2 to 2.5 mm
Devices of collecting blood through skin puncture
Capillary tubes
Microcollection tubes
Order of draw (Skin puncture) “T S E O S”
Tube for blood gas analysis
Slide
EDTA
Other anticoagulants
Serum
Most common site (Venipuncture)
Superficial veins of antecubital fossa
Choice of veins
- Median cubital
- Cephalic
- Basilic
Angle bet. skin and needle (Venipuncture)
< 30 degrees
Tourniquet application (Lenth of time)
Less than 1 minute
Effects of prolonged tourniquet application
Hemoconcentration
Hemolysis
Shortened coagulation time
Most important practice to prevent spread of infectious disease
At least 15 seconds
Handwashing
Tourniquet application (Distance)
3 to 4 inches
7.5 to 10 cm
Common needle size and length for adult venipuncture
21 G (Needle size)
1 inch (Length)
Causes of specimen hemolysis (5)
Prolonged tourniquet application
Moisture/ contamination in blood collection tube
Needles with too small bore
Excessive agitation
Frothing of blood sample
Anticoagulants for venipuncture (3)
EDTA
Heparin
Sodium citrate
Prefererred anticoagulant for platelet countd
EDTA
Lavender/ Purple top
No. of inversions = 8x
For hematology
Action = Chelation of calcium
EDTA or Ethylenediaminetetraacetic acid
Green top
No of inversions = 8x
Used for = Flow cytometry, Plasma chemistry, OFT, Blood gas studies
Action = Binds to anti thrombin
Optimal anticoagulant concentration = 15-20 units/ml of blood
Heparin
Light blue top
No of inversions = 3-4x
For coagulation studies
Action = Chelation of calcium
3.2 Sodium citrate
Order of draw (Venipuncture) “B C S H E S”
Blood culture
Citrated
Serum
Heparin
EDTA
Sodium fluoride
Other blood collection tubes:
SPS (Sodium Polyethanol Sulfonate) or ACD (Acid Citrate Dextrose)
For blood culture
Yellow top
Other blood collection tubes:
K2 EDTA
Lead determination = contains < 0.01 ug/ml lead
Tan top
Other blood collection tubes:
K2 EDTA
For toxicology, trace element determination = low levels of trace elements
Royal blue top
Other blood collection tubes:
K2 EDTA with GEL
For molecular diagnostic tests
White top
Other blood collection tubes:
3.8% Sodium citrate
For westergren/ ESR
Black top
Other blood collection tubes:
K2 EDTA
For blood bank test and whole blood hematology determination
Pink top
Other blood collection tubes:
Either be 3.2% sodium citrate or CTAD (Citrate, Theophyline, Adenosine, Dipyridamole)
For coagulation tests or Platelet function tests
Light blue top
Peripheral Blood Smear:
Sources of Specimens
EDTA blood
Anti-coagulant free blood
EDTA blood spears should be made within _____ hours after collection.
2 hours
Advantages of EDTA Blood Smear (3)
Multiple blood smears
May be prepared at a later time
Proventd platelet clumping or aggregation
Disadvantages of EDTA blood smear (2)
Platelet satellitosis
EDTA-induced platelet clumping
Advantages of Anticoagulant-free blood (2)
Made at the px side
Some artifacts may be prevented
Disadvantages of Anticoagulant-free blood (2)
Platelet clumpingb
Few films can be made
Methods of blood film preparation (3)
Two-glass method (Manual wedge method)
Coverslip method
Automated methods
Angle bet. pusher slide and film slide
30 to 45 degrees
Scanning methods (2)
Longitudinal - Tail to head
Battlement - Bakcck and forth serpentine
Two types of coverslip technique
Glass slide-coverslip method or Beacom’s
Two-coverslip method or Ehrlich’s
Methods of film preparation:
Rarely used
Used for making Bone marraw aspirate
Excellent for WBC distribution
Coverslip technique
Two types of automated methods
Miniprep = semi auto, prortable
Centrifugal (Spinner) Type = uses 0.2 well-mixed anticiagulated blood and has even distribution of blood cells
Coulter LH
Sysmex SP-10
Techniques for blood film staining:
1. Fixative
2. Stain
3. Buffer
- Methanol
- Wright or wright-giemsa
- 0.5 M Sodium Phosphate
Any stain which consists methylene blue and halogenated flurescein dye
Romanowsky-type stain
Basic stain
Stains nucleus and some cytoplasmic structures a blue or purple color
Methylene blue
Acidic stain
Stains cytoplasmic structures an orange-red color
Eosin
What type of stain are the following:
Wright stain
Giemsa
May-grunwald stain
Romanosky-type stain
Techniques of staining (3)
Manual
Automated
Quick
Characteristics of Well-stained Smear (Macroscopic)
Pink to purple
Characteristics of Well-stained Smear (Microscopic)
What are the demostrated color of the following:
1. RBC
2. WBC Nuclei
3. Neutrophil cytoplasm
4. Eosinphil granules
- Orange to salmon pink
- Purple to blue
- Pink to tan with violet to lilac granules
- Bright-orange
Evaluation of PBS:
Unusual findings = Blood film bluer than normal
Increased blood proteins
Plasma cell myeloma or Multiple myeloma
Evaluation of PBS:
Unusual finding = Grainy appearance
RBC agglutination
Evaluation of PBS:
Unusual findings = Holes all over the films
Increased lipid levels
Evaluation of PBS:
Unusual findings = Blue specks
Markedly increased WHC counts and platelet counts
Microscopic Examination
Objective that:
Assess overall film quality
Detect snoplow effect
Detect fibrin strands
Recognize rouleaux formation
10x objective or LPO
Microscopic examination
Objective that:
Red cells have central pallow
Cells are appropriately stained
40x high dry or 5x OIO
Multiplication factor of 40x high dry
x 2000
Multiplication factor of 50x OIO
x 3000
Microscopic examination
Objective that:
Examine nuclear details of WBC
For tabulation of actual WBC differential and estimation of platelet count
100x OIO
Parasites that may appear in the blood smear (3)
Malaria
Filaria
Trypanosomes
Malaria species that infect humans (5)
P. falciparum
P. vivax
P. ovale
P. malariae
P. knowlesi
Patients resistant to falciparum infection.
Sickle cell patients
Most pathologic malaria specie
P. falciparum
Most prevalent plasmodium specie
P. vivax
Blood films:
Ideal for initial screening of blood
Stained with a water-based wright giemsa without methanol fixation
Thick blood films
Blood films:
For species identification and determination of percent parasitemia
Stained after methanol fixation
Thin blood films
How many fields on the thick and thin blood films must be examined for malaria?
300 fields
Filaria species that infect humans (3)
Wuchereria bancrofti
Brugia malayi
Loa loa
Trypanosomes species that infect humans (3)
Trypanosoma brucei rhodesiense
Trypanosoma brucie gambiense
Trypanosoma cruzi
Storage of blood smear slides
At least 7 days before proper disposal