Phlebotomy is collection of blood

Phlebotomy is the practice of drawing blood from a patient for diagnostic, therapeutic, or donation purposes. Blood collection is essential in diagnosing diseases, monitoring health conditions, and conducting medical research. This lecture will cover the history, techniques, equipment, safety protocols, and different types of blood collection: capillary, venous, and arterial.

History of Phlebotomy

– Ancient Practices: Bloodletting was common in ancient civilizations like the Egyptians, Greeks, and Romans. It was believed to balance bodily fluids and treat various ailments.
– Middle Ages: Barber-surgeons performed bloodletting using lancets and leeches. The red and white barber pole is a remnant of this era, symbolizing blood and bandages.
– Modern Era: Advances in medical science in the 19th and 20th centuries shifted the focus from bloodletting to diagnostic blood sampling. Today, phlebotomy is a standardized procedure performed by trained professionals.

Equipment and Supplies

– Needles: Different gauges for different purposes (e.g., 21-gauge for routine blood draws, 23-gauge for children or difficult veins).
– Vacutainer Tubes: Color-coded tubes for various tests (e.g., lavender for CBC, green for chemistry tests).
– Tourniquet: Used to engorge veins and make them easier to locate.
– Alcohol Swabs: To disinfect the puncture site.
– Gloves: Personal protective equipment to prevent contamination.
– Gauze and Bandages: For post-draw care.
– Lancets: Used for capillary blood collection.
– Syringes: Sometimes used for venous or arterial blood draws.
– ABG Kit: For arterial blood gas collection.

Types of Blood Collection

1. Capillary Blood Collection

• Indications

– Used for small volume blood tests.
– Ideal for pediatric patients, patients with difficult veins, and home monitoring (e.g., glucose testing).

• Procedure

1. Hand Hygiene: Wash hands and put on gloves.
2. Identify the Patient: Verify patient identity using at least two identifiers.
3. Select the Site: Common sites include the finger (adults) or heel (infants).
4. Warm the Site: If necessary, warm the site to increase blood flow.
5. Disinfect the Site: Use an alcohol swab to clean the area.
6. Perform the Puncture**: Use a sterile lancet to puncture the skin.
7. Collect the Blood: Gently squeeze the area to collect the required amount of blood into a capillary tube or onto a collection strip.
8. Apply Pressure: Use gauze to apply pressure to the site until bleeding stops.
9. Label and Transport**: Properly label the sample and prepare it for transport to the lab.

2. Venous Blood Collection

•  Indications

– Used for most diagnostic tests, including complete blood count (CBC), blood chemistries, and blood cultures.

• Procedure

1. Preparation: Identify the patient, gather equipment, and wash hands.
2. Apply the Tourniquet: 3-4 inches above the intended puncture site.
3. Select the Vein: Common veins include the median cubital, cephalic, and basilic veins.
4. Disinfect the Site: Use an alcohol swab in a circular motion from the inside out.
5. Insert the Needle: Bevel up, at a 15-30 degree angle into the vein.
6. Collect the Blood: Attach the vacutainer tube to the needle holder and fill the required tubes.
7. Release the Tourniquet: Once blood flow is established.
8. Remove the Needle: Apply gauze over the site and withdraw the needle.
9. Apply Pressure and Bandage: To stop the bleeding and protect the puncture site.
10. Label and Transport: Properly label the samples and prepare for transport.

3. Arterial Blood Collection

• Indications

– Used for blood gas analysis to assess oxygenation, ventilation, and acid-base status.

• Procedure

1. Preparation: Identify the patient, gather equipment, and wash hands.
2. Select the Site: Common sites include the radial artery (preferred), brachial artery, or femoral artery.
3. Perform the Allen Test: To ensure collateral circulation in the hand.
4. Disinfect the Site: Use an alcohol swab in a circular motion.
5. Insert the Needle: Bevel up, at a 45-60 degree angle into the artery.
6. Collect the Blood: Allow the syringe to fill with arterial blood (usually under its own pressure).
7. Remove the Needle: Apply immediate pressure to the site for at least 5 minutes.
8. Apply a Pressure Dressing: To ensure hemostasis.
9. Label and Transport: Properly label the sample and place it in an ice slurry for transport.

Complications and Troubleshooting

1. Hematoma:

Caused by blood leaking into the surrounding tissue.

• Prevention: Apply adequate pressure post-draw.

2. Syncope: Fainting during or after the procedure.

•  Prevention: Have the patient lie down if they have a history of fainting.

3. Hemolysis:

Destruction of red blood cells during collection.

• Prevention: Use the correct needle size and avoid excessive force.

4. Arterial Spasm:

In arterial puncture, causing pain and difficulty in obtaining the sample.

• Prevention: Ensure proper technique and handle tissues gently.

Safety and Infection Control

– Personal Protective Equipment (PPE): Always wear gloves and, if necessary, additional protective gear.
– Hand Hygiene: Before and after each procedure.
– Needlestick Prevention: Use safety-engineered devices and never recap needles.
– Disinfection: Properly disinfect the puncture site and work area.
– Waste Disposal: Dispose of needles and other sharps in designated containers.

Special Considerations

– Pediatric Phlebotomy: Use smaller needles and pediatric tubes. Distraction techniques can help ease anxiety.
– Geriatric Phlebotomy: Veins may be fragile; use a gentle technique and smaller gauge needles if necessary.
– Patients with Difficult Veins: Consider alternative sites or techniques such as ultrasound guidance.

Conclusion

Phlebotomy is a vital procedure in clinical practice, requiring a combination of technical skill, knowledge, and patient care. By adhering to proper techniques and safety protocols, phlebotomists can ensure accurate test results and minimize patient discomfort and complications.

Questions and Discussion

Feel free to ask any questions or discuss specific scenarios you may have encountered during phlebotomy.