Lecture 12b - Specimen Collection Part 2 Flashcards
In vivo
Inside of the body (blood in liquid form)
In vitro
Outside of the body (solid form)
What are the three layers present within a centrifuged SST tube?
Serum, gel separator, and clotted RBCs.
What are the three layers present within a centrifuged plasma tube?
Plasma, buffy coat, and erythrocytes (RBCs)
What kind of education/training is needed to become a phlebotomist?
Typically on the job trained, but certificate programs are available.
What are three types of venipuncture techniques?
- Vacutainer
- Syringe Method
- Butterfly
Where are the two common locations on the body where capillary blood is drawn?
- Finger
2. Heel
How does the gauge size relate the the size of the needle?
The larger the gauge size, the smaller the inner diameter.
What type of safety control is a vacutainer hub?
An engineering control - protects user from accidental needle sticks.
What is a advantage and disadvantage of using the butterfly method for venipuncture?
Smaller gauge needle may take longer, but needs to be saved for elderly patients/patients with small veins.
For venipuncture, what implied consent is used?
Arm out
How many verbal patient identifiers must be given prior to collecting lab samples?
Two; first and last name and DOB.
Can an armband be used to confirm patient identity?
Yes, but you still need two verbal identifiers.
(T/F) A patient can never refuse a blood draw.
False, a patient can always refuse.
Hematoma
Collection of blood under the skin which can be caused by needle bevel is half in the vein and half in the tissue, or premature needle removal.
Where should you label patient specimens?
Always label in the presence of the patient.
At what stage of the venipuncture process should you invert anticoagulant tubes?
While you are applying the bandage and cleaning up supplies.
Where do you draw blood if the antecubital veins have an H pattern orientation?
Median Cubital Vein
Where do you draw blood if the antecubital veins have an M pattern orientation?
Median Vein
What are some special considerations and areas to avoid when selecting a vein?
- Arteries
- IV Lines
- Edema
- Scarring or Burn Patients
- Dialysis Patients
- Mastectomy Patients
- Tendons
What are some special considerations for Mastectomy patients?
If lymph nodes were removed, you should draw on the opposite side.
In what order should evacuated tubes be collected?
Light yellow (SPS); Light Blue Top; Red Top; SST (gold); PST (mint); Dark Green; Lavender; Gray
Stop Light Red Stay Put Green Light Go
If a wrong tube was collected, what adverse effect on test results could occur?
- Assay interference
- Constituent removal
- Effect on enzymes
- Alteration of cellular structures
- Incorrect amount of anticoagulant
In what circumstances should a capillary stick be used?
- Neonatal testing
- Blood glucose testing
- Hard sticks
What are some advantages of capillary sticks?
- Small sample size –> Common for POC testing
2. Hard draws
What are some disadvantages of capillary sticks?
- Specimen acceptability
2. Small sample size
(T/F) When doing a capillary stick procedure, the position of the lancet blade should be parallel to the whirls on the finger?
False, you should always be perpendicular.
Hemolysis
Rupture of the RBC membrane, releasing hemoglobin into the plasma/serum.
What are the common causes of hemolysis?
- Pulling back too fast on a syringe
- Forcing blood into an evacuated tube
- Excessive trauma during venipuncture
What test(s) can hemolysis cause a false increase?
Potassium and certain enzymes
What is a lipemic specimen?
Serum/plasma with the presence of excess fats or lipids. Has a milky white color.
Commonly caused by blood draw too close to a meal, or very high lipid levels.
Test affected: triglycerides, cholesterol, etc.
What is an icteric specimen?
Serum/plasma with the presence of excess bilirubin. Has a brownish-yellow color.
Caused by excessive intravascular hemolysis, obstruction of the bile duct, or impairment of the liver.
Test affected: Photometric assays
How does temperature affect specimen stability?
Lower the temperature, the greater the specimen stability.
What specimen storage is most common?
Refrigeration
What happens to RBCs if they are frozen?
They get lysed
How should bilirubin samples be stored?
Protected from light
(T/F) Serum/plasma must be removed from RBCs prior to storage?
True
