METHODS OF BLOOD COLLECTION Flashcards
What is a method of blood collection by skin puncture?
Capillary puncture
What is the blood collection method of choice with pediatric patients?
Capillary puncture
What is a useful blood collection method for adults with extreme obesity, severe burns, and thrombotic tendencies?
capillary puncture
Where is blood collected from with capillary punctures?
- heel
- finger
- earlobe
- toe
What is the most common site for capillary puncture in infants?
Plantar surface of the heel perpendicular to the big toe
What is the site of blood collection for capillary punctures in older infants and elderly people?
the palmer (fleshy) surface of the distal phalanx of the middle finger or ring finger, with the middle finger being the first choice
What is a blood collection procedure via the patient’s vein?
venipuncture method
What is considered the best method of blood collection?
Venipuncture
What is a primary source of specimen for clinical laboratory analyses because of the relative ease of obtaining it?
Venous blood
What is the equipment needed for a capillary puncture?
- sterile gauze pads
- 70% ETOH or Betadine solution
- Lancet
- Capillary tubes or QBC Star tube
- Bandage
What is the max depth the lancet should not exceed into the fingertips?
2mm
What should you do to avoid dilution of the specimen with tissue fluid when performing a capillary puncture?
Wipe away the first drop of blood
True or False
You should squeeze the finger when performing a capillary puncture
False
you should avoid squeezing and use gentle pressure
How close to the skin should the capillary tube be placed to the skin of the fingertip when performing a capillary puncture?
15 degrees
Why should you not draw from IV sites?
It dilutes the specimen and can alter test results
What is the equipment needed for a venipuncture?
- sterile gauze pads
- 70% ETOH/Betadine solution
- Tourniquet
- Vacutainer needle
- Vacutainer holder
- Vacutainer tubes
Where should the tourniquet be placed on the patients arm when performing a venipuncture?
about 2-3 inches above the antecubital area
Can you use a blood pressure cuff for patients whose veins are difficult to find?
yes
How should the needle be positioned against the skin when performing a venipuncture?
15 degree angle with the skin, bevel up
True or False
You should gently shake the tube with an anticoagulant and mix well to prevent clotting
False
gently invert any tubes with anticoagulant and mix well to prevent clotting
What must be used to obtain a whole blood specimen for testing?
an anticoagulant
What is a liquid coagulant used in purple tops?
Ethylenediaminetetracetic Acid (EDTA)
What hematology studies is EDTA usually used in?
- CBC
2. Differential WBC
What is the most widely used anticoagulant?
EDTA
Does EDTA affect cellular morphology?
No
How long can specimens be refrigerated for?
approximately 24 hours
What is a powder anticoagulant used in light blue tops?
sodium citrate
What coagulation studies is sodium citrate typically used for?
- Prothrombin Time (PT)
2. Partial Thromboplastin Time (PTT)
What is a liquid or powder anticoagulant in green tops?
Heparin
What anticoagulant inhibits the clotting enzyme, thrombin, by creating an antithrombin ?
Heparin
What plasma studies and chemistry testing (piccolo chemistry analyzer) is heparin typically used for?
- Ammonia
2. Adrenocorticotropic hormone (ACTH)
Red top tubes
No anticoagulants or additives Used mainly for: 1. chemistry 2. serology 3. blood bank 4. other testing requiring serum
Serum separator tube (SST)/Gold Top, Tiger Top, HIV tube (red/yellow)
- No anticoagulant
- contains a serum separator gel
- primarily used for chemistry testing
Sodium fluoride
- grey top tube
- used for glucose studies
- ETOH level analysis
- Inhibits Glycolysis
Phlebotomy procedural errors
Using IV sites will result in what?
Dilution of the sample with intravenous fluids
Phlebotomy procedural errors
Prolonged application of a tourniquet will produce what?
an increase in blood cell concentration (hemoconcentration)
Phlebotomy procedural errors
What would happen if you used to wrong tube?
unable to perform the correct test
True or False
You should draw specimens into non-additive tubes before tubes with additives
True
What could happen if you short fill a sample tube?
could render the specimen unacceptable due to the quantity not being sufficient to perform the test
What are these examples of?
- Syncope (fainting)
- Infection
- Continued bleeding
Blood Draw Complications
