Ch 2 Methods of blood collection Flashcards
A method of blood collection by skin puncture
Capillary puncture
Blood collection method of choice in pediatric patients, extreme obesity, severe burns, and thrombotic tendencies
Capillary puncture
Capillary puncture collection sites
Heel, finger, earlobe, or toe
First choice of finger in capillary puncture
Middle
A blood collection procedure in the patient’s vein
Venipuncture
Best method of blood collection
Venipuncture
Primary source of specimen for clinical laboratory analyses
Venipuncture
Capillary puncture equipment
Sterile gauze pads
Alcohol/betadine solution
Lancet
Capillary tubes or QBC star tube
Bandage
Capillary puncture procedure is also known as
Fingerstick method
Prior to using a lancet, massage or “milk” the finger down toward the fingertip for how many times?
Repeat 5-6 times
Part of the finger used for the lancet
Side of the finger (off center), across the striations of the fingertip
Max depth of lancet should not exceed:
2mm
What should you do to avoid dilution of the specimen with tissue fluid?
Wipe away the first drop of blood
What kind of pressure should you use to receive blood from a fingerstick?
Gentle pressure, avoid squeezing
Obtain specimen with capillary tube placed:
Almost horizontally (15 degrees to finger tip)
Why do you not draw from IV lines?
It dilutes the specimen
Venipuncture equipment
Sterile-gauze pads
Alcohol/Betadine
Tourniquet
Vacutainer needle
Vacutainer holder
Vacutainer tubes
Venipuncture:
Patient position
Lying in bed or sitting in chair with arm propped up
Apply tourniquet around the patient’s arm above the antecubital area:
2-3 inches
Tourniquet
Use enough tension to:
Compress the vein but not the artery
Use blood pressure cuff on patients whose veins are difficult to find at:
30 mm/Hg
Venipuncture
Position patient’s arm:
Extended with little to no flexion at the elbow
If vein is difficult to find:
Massage the arm with an upward motion to force blood into the vein
Using a smooth continuous motion, introduce the needle at:
15-degree, bevel up
Venipuncture
Have the patient hold pressure for at least:
3 minutes
Liquid anticoagulant used in purple tops
Ethylenediaminetetraacetic Acid (EDTA)
Purple top labs
CBC
Differential WBC
Most widely used anticoagulant
EDTA
Chelating agent used in a CBC that binds calcium so blood cannot clot
EDTA
Purple top specimens can be refrigerated for:
24 hours
Powder anticoagulant used in light blue tops
Sodium citrate
Light blue top labs
Prothrombin time (PT)
Partial thromboplastin time (PTT)
Chelating agent used in a PTT that binds calcium
Sodium citrate
Liquid or powder anticoagulant used in green tops
Heparin
Typically used for plasma studies and chemistry testing
- Ammonia
- Adrenocorticotropic hormone (ACTH)
Green top
Inhibits the clotting enzyme, thrombin, by creating an antithrombin
Heparin
Anticoagulant used in red tops and tiger tops
NONE
Red top labs
Chemistry
Serology
Blood bank
Other tests requiring serum
Contains serum separator gel
SST/Gold top, Tiger top, HIV tube (red/yellow)
Used in grey tops to inhibit glycolysis
Sodium fluoride
Grey top labs
Glucose studies
ETOH level analysis
Prolonged application of a tourniquet will:
Produce a measurable increase in blood cell concentration (Hemoconcentration)
Using the wrong tube type:
Inability to perform test
Wrong draw order results in:
Possible contamination
What tubes should be drawn first?
non-additive tubes before tubes with additives
Fill additive-containing tubes in the following order:
Blood culture
Blue top
Red top
SST (HIV)
Green top
Lavender top
Grey top
Short fill of lab could:
Render the specimen unacceptable due to quantity not sufficient to perform test
Improper anticoagulant/blood ratio
Not mixing the tube could result in:
Blood clots
Infection could be caused by:
Inadequate cleaning of area
Treat with antibiotics, refer to MTF
Occurs when integrity of the vein is compromised. Blood is leaking into the tissues.
Hematoma
What should you do if there is a hematoma around the site?
Stop the procedure and apply pressure with clean gauze
Have patient elevate arm