Blood Collection Methods Quiz

Blood Collection Methods

• Collecting blood samples is important for disease prevention and treatment, but can be a distressing experience for patients.
• Capillary blood collection uses thin tubes (capillary tubes) where blood flows against gravity into the tubes. This method is used for small blood volumes.
• Peripheral blood collection uses capillary tubes and involves pricking the finger, heel, or earlobe (in infants).
• Venous blood collection is used for larger blood volumes; a vein is punctured to collect blood.

Capillary Blood Collection Procedure

• Disinfect the area with 70% alcohol, allow to dry.
• Use a lancet to make a puncture about 3mm deep.
• Wipe away the first drop of blood.
• Apply gentle pressure to prevent excessive pressure and tissue fluid dilution.
• Collect the blood into a capillary tube.

Venous Blood Collection Procedure

• Identify the patient and prepare the equipment (tourniquet, alcohol, cotton, adhesive strip, sterile syringes, suitable tubes).
• Place a tourniquet above the puncture site.
• Insert a needle at a 30-degree angle into a vein.
• Collect the blood into a syringe or evacuated tube.
• Remove the tourniquet and needle quickly, applying pressure to the puncture site.
• Transfer blood to the appropriate collection vials.

Blood Collection Considerations

• Avoid placing a tourniquet on a patient for more than 2 minutes.
• The tourniquet should not be placed too tightly.

Blood Type Differences

• Arterial blood is bright red due to high oxygen levels.
• Venous blood is dark red or blackish due to lower oxygen levels.

Vacuum Tubes

• Different colored vacuum tubes contain varying anticoagulants.
• Different anticoagulants are used depending on the requirements of the blood tests to be performed.
• Common color codes include:
  • Purple: EDTA for complete blood counts
  • Red: No anticoagulant for serological tests
  • Blue: Sodium citrate for coagulation tests
  • Gray: Fluoride for blood sugar tests