Final answer:
The correct order of draw for multiple blood samples, adhering to CLSI standards, includes the sequence of blood culture bottles, coagulation tubes, serum tubes, heparin tubes, EDTA tubes, glycolytic inhibitor tubes, and other additive tubes. This sequence is vital to prevent cross-contamination and ensure accurate laboratory test results.
Step-by-step explanation:
Order of Draw for Multiple Blood Samples
When multiple tubes must be drawn during a venipuncture, it is crucial to follow the standard order of draw as recommended by the Clinical Laboratory Standards Institute (CLSI). The proper order of draw adheres to CLSI standards to prevent cross-contamination and ensure accurate test results. Blood should generally be collected in the following sequence: blood culture bottles, coagulation tubes, serum tubes with or without clot activator, heparin tubes, EDTA tubes, glycolytic inhibitor tubes, and other additive tubes. This sequence helps to avoid the carryover of additives between tubes that can interfere with test results. For example, drawing a tube with EDTA before a tube intended for coagulation studies could lead to falsely prolonged clotting times because the EDTA could remove calcium from the sample.
In the context you have provided, tubes containing different additives such as lithium heparin, K2EDTA, and tubes for heparinized plasma are mentioned. It is essential for the technician to follow the correct order to prevent contamination or interference between the chemical additives in the various tubes, which can affect the outcomes of plasma analyses and the various pretreatment procedures such as with methanol, SPE cation-exchange cartridges, and ACN (acetonitrile).