Methods of Blood Collecting Flashcards
Capillary puncture is the method of choice for what types of patients?
Pediatric patients
Extreme obesity
Severe burns
Thrombotic tendencies
Where can you collect blood from in a capillary puncture? What are preferred sites?
Heel, finger, earlobe, toe
Adults: Palmar surface of the distal phalanx of the middle or ring finger. Middle finger is the first choice.
What is the best method of blood collection?
Venipuncture
Why shouldn’t you draw blood from IV sites?
It dilutes specimen and alters test results.
What is the max depth of a lancet stick?
2mm info the fingertip
Why do you wipe the first drop of blood in a finger stick?
To avoid dilution from tissue fluid.
How should the capillary tube be placed when collecting blood from a finger stick?
15 degrees horizontally
Where should the tourniquet be placed during venipuncture, and how long should it stay on at a maximum?
2-3 inches above the AC
1 minute
A BP cuff inflated to 30mmHg can be used for difficult veins.
How long should a patient hold pressure on the puncture site after venipuncture?
3 minutes
What anticoagulant is used in purple/lavender tops?
Ethylenediaminetracetic Acid (EDTA)
Liquid anticoagulant.
It is a chelating agent that binds to calcium to prevent clots.
Specimens can be refrigerated for 24 hours.
Purple tops contain __ and are used for what types of studies?
EDTA
Hematology studies
- CBC/with diff
- ESR
- A1C
Light blue tops contain what anticoagulant?
Sodium Citrate
Liquid anticoagulant
It is a chelating agent that binds to calcium.
Typically only food for 4 hours after collection.
Light blue tops contain what anticoagulant and are used for what studies?
Sodium Citrate
Coagulation studies
- PT
- PTT
- Fibrinogen
- D-Dimer
Green tops contain what anticoagulant?
Heparin
Liquid or powder anticoagulant
Inhibits thrombin by creating an antithrombin. (Prevents the conversion of prothrombin into thrombin.)
Green tops contain __ and are used in?
Heparin
Plasma studies and chemistry testing
- Ammonia
- ACTH
What tube contains no anticoagulants or additives? What is it used for?
Red top
Chemistry
Serology
Other tests requiring serum
These tubes do not contain a anticoagulant, but do contain a serum separator gel. What are they used for?
SST/Gold Top/Tiger Top/Red Yellow HIV Tube
Used for chemistry testing
Gray top tubes contain what anticoagulant and are used for what?
Sodium fluoride - inhibits glycolysis.
Used for glucose studies and ETOH levels.
What is hemoconcentration?
Measurable increase in blood cell concentration due to prolonged application of a tourniquet.
What is the correct tube filling order?
Fill additive containing tubes in the following order:
- Blood culture tubes
- Blue top
- Red top
- SST
- Green top
- Lavender top
- Gray top
A short fill results in what?
Improper anticoagulant-blood ratio
What would a Chief Petty Officer refer to syncope as?
Fainting
