Understanding The Order Of Draw: Importance, Tubes Used, and Protocol

Summary

• Understanding the order of draw is crucial in preventing specimen contamination and ensuring accurate Test Results.
• There are different colored tubes used in the order of draw, each containing different additives to preserve the specimen for specific tests.
• Following the proper order of draw can help maintain the integrity of the specimen and improve patient care outcomes.

Medical laboratory testing plays a critical role in diagnosing and treating various health conditions. It is essential for Healthcare Providers to collect accurate and reliable specimens to ensure accurate Test Results. One important aspect of specimen collection is the order of draw, which refers to the sequence in which multiple blood tubes are filled during Venipuncture. This article will explore how many tubes are used in the order of draw and why following this protocol is important.

What is the order of draw?

The order of draw is a standardized sequence that healthcare professionals follow when collecting blood samples for multiple tube tests. Following the proper order of draw helps minimize the risk of specimen contamination, ensure accurate Test Results, and improve patient care outcomes. The order of draw is based on the principle that certain additives or anticoagulants in blood collection tubes can interfere with the accuracy of certain tests if mixed in the wrong order.

How many tubes are used in the order of draw?

The number of tubes used in the order of draw can vary depending on the specific tests being ordered. However, there are some common blood collection tubes that are used in the order of draw. These tubes are color-coded to indicate the additive or Anticoagulant they contain, which helps Healthcare Providers follow the correct sequence when collecting blood samples. The most commonly used tubes in the order of draw include:

1. Yellow (Sterile)

1. The yellow tube is typically used first in the order of draw and contains a solution of acid citrate dextrose (ACD) or acid-citrate-dextrose solution A (ACD-A).
2. This tube is used for blood cultures and molecular Diagnostic Tests.

2. Light Blue (Sodium Citrate)

1. The light blue tube contains Sodium Citrate, which is an Anticoagulant that prevents blood clotting by binding with calcium in the blood.
2. This tube is used for coagulation studies, such as Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT).

3. Red (No Additive)

1. The red tube does not contain any additives and is used for serum chemistry tests, such as Blood Glucose, cholesterol, and kidney function tests.
2. This tube allows the blood to clot naturally, and the serum can be separated from the clotted blood for testing.

4. Gold or Tiger Top (Clot Activator and Gel Separator)

1. The gold or tiger top tube contains a Clot Activator and gel separator, which helps separate serum from the blood after centrifugation.
2. This tube is also used for serum chemistry tests and is commonly used for basic metabolic panels (BMP) and comprehensive metabolic panels (CMP).

5. Green (Heparin)

1. The green tube contains Heparin, an Anticoagulant that inhibits the clotting process by activating the enzyme antithrombin.
2. This tube is used for plasma determinations for tests such as ammonia, STAT chemistry, and STAT electrolytes.

6. Lavender (EDTA)

1. The lavender tube contains ethylenediaminetetraacetic acid (EDTA), which is an Anticoagulant that binds with calcium ions in the blood to prevent clotting.
2. This tube is used for hematology tests, including complete blood count (CBC), sedimentation rate, and blood typing.

Why is the order of draw important?

Following the proper order of draw is essential for maintaining the integrity of the specimen and ensuring accurate Test Results. Mixing blood additives or anticoagulants in the wrong order can lead to inaccurate Test Results, specimen hemolysis (rupturing of red blood cells), or sample contamination. The order of draw is designed to prevent Cross-Contamination between tubes and ensure that each tube contains a pure blood sample for testing.

Compliance with the order of draw also helps improve patient care outcomes by reducing the risk of misdiagnosis or inappropriate treatment decisions based on faulty Test Results. Healthcare Providers must follow established protocols for specimen collection to uphold patient safety and quality of care standards. By understanding the importance of the order of draw and using the appropriate tubes in the correct sequence, healthcare professionals can help guarantee the reliability and accuracy of laboratory Test Results.

In conclusion, the order of draw is a critical component of the specimen collection process in medical laboratory testing. Understanding how many tubes are used in the order of draw and following the correct sequence when collecting blood samples is essential for maintaining the integrity of the specimen and ensuring accurate Test Results. Healthcare Providers must adhere to established protocols and guidelines to prevent specimen contamination and improve patient care outcomes.

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