ICU Advantage Lecture: Order of Draw for Blood Sampling

Introduction

• Presenter: Eddie Watson
• Topic: Proper order of draw in blood sampling/phlebotomy
• Importance: Ensures accurate patient results, prevents cross-contamination, and misdiagnosis
• Goal: Understand key takeaways about the order of filling blood tubes

Importance of Order of Draw

• Proper order prevents additives in tubes from contaminating others
• Inaccurate results can lead to misdiagnosis and improper treatment
• Cross-contamination can impact patient care

Blood Sampling Tubes and Their Uses

Blood Cultures

• Order: First to be drawn
• Purpose: Sterile collection to identify bacterial growth
• Components:
  • Nutrient broth for bacterial growth
  • Anticoagulants
  • Chemicals to reduce bacterial killing by blood
• Order:
  • Aerobic first (accommodates air in syringe)
  • Anaerobic second

Light Blue Tube

• Type: Coagulation Tube
• Tests: PT, INR, PTT, Anti-Xa, Fibrinogen, D-Dimer
• Additives: Sodium citrate, binds calcium
• Importance: Must be filled to a specific line for proper ratio

Red Top Tube

• Usage: Chemistry panels, serum tests
• Additives: Often none or silica clot activator

Gold or SST (Serum Separator Tube)

• Purpose: Chemistry tests, often send-out tests
• Additives: Gel for separating cells from serum, possible clot activator

Green Top Tube

• Common Chemistry Tube
• Tests: Troponin, various chemistry tests
• Special handling: Some tests require the sample to be iced
• Additives: Heparin, plasma separating gel

Purple Top Tube

• Type: Hematology Tube
• Tests: CBC, ESR, A1C
• Additives: EDTA (preserves cell morphology, binds calcium)
• Note: High potassium content

Pink Top Tube

• Purpose: Blood typing
• Additives: Same as purple tube (EDTA)

Gray Top Tube

• Tests: Lactate, ethanol, fasting glucose
• Additives:
  • Sodium fluoride (stops glycolysis)
  • Potassium oxalate (prevents clotting)

Proper Order of Draw

1. Blood Cultures - Sterile
2. Light Blue - Coagulation studies
3. Red Top - Not common chemistry
4. Gold/SST - Not common chemistry
5. Green Top - Common chemistry
6. Purple Top - Hematology
7. Pink Top - Blood typing
8. Gray Top - Specialized tests

Importance of Proper Order

• Prevents contamination and ensures accurate test results
• Avoids skewed results for potassium, calcium, etc.
• Essential for proper patient diagnosis and treatment

Mnemonic for Order of Draw

• Silly Mnemonic: Stoplight Red Stay Green Power Light Go
• Breakdown:
  • S: Sterile (Blood Cultures)
  • L: Light Blue
  • R: Red
  • S: SST (Gold)
  • G: Green
  • P: Purple
  • L: Light Pink
  • G: Gray

Conclusion

• Ensure proper order of draw to avoid cross-contamination
• Memorize order for efficient and accurate phlebotomy
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