Phlebotomy is a critical facet of patient care and research. However, mix-ups and errors caused during blood draws can lead to potentially dangerous situations; at best, the patient has to come back to the clinic for an additional blood draw, and at worst, the patient can be misdiagnosed and left without proper treatment. Here are several tips to ensure that phlebotomy collection is performed appropriately, with minimal risk for error.

Label clearly

Labeling errors are some of the most dangerous, especially when collecting blood samples from patients. Not only are the additional financial costs of mislabeled tubes substantial (712$ per mislabeled specimen on average), but the potential damage of misdiagnosing a patient can be life-threatening for those that require specialized care.¹ Always ensure you’re up to date with your institution’s guidelines on phlebotomy labeling, including using suitable labels and verifying that the correct information is printed. It is also recommended that each tube be labeled after blood has been drawn instead of labeling batches of tubes before in order to reduce the risk of misidentified specimens.²

Avoid hemolysis

Hemolysis is one the most common causes of rejected samples in the clinic, resulting in the need to perform a repeat draw and wasting time and resources. Naturally, these samples are rejected due to potassium leakage into the sample, which can severely distort normal readings. Identifying potential hemolysis can be time-consuming as well, as it requires visual inspection after centrifugation of the sample and comparison with the hemolytic chart. To avoid hemolysis, several tactics can be used, including:³

• Avoiding IV line draws
• Avoiding heavy mixing
• Avoiding strong withdrawal pressure from the syringe
• Avoiding rimming clots to remove fibrin
• Training to position needles optimally to avoid occlusion by the vein wall
• Prewarming skin puncture sites
• Avoiding underfilling the tubes
• Using the correct needle size
• Removing the tourniquet promptly

Follow the right order of draw

The draw order represents the sequence of blood sample tubes used for collection during phlebotomy. When followed incorrectly, cross-contamination of additives and anticoagulants can occur, leading to sample errors and repeat draws. The most widely accepted order of blood draws is the following:⁴

• Blood culture tubes
• Sodium citrate tubes
• Serum tubes with/without clot activator or gel separator
• Heparin tubes with/without gel separator
• EDTA tubes
• Glycolysis inhibitor tubes

To ensure the correct tube is used for each step, familiarize yourself with the correct draw step sequence and always double-check the tube colors and labels.

Mix additives accordingly

Once blood is drawn, an additive may be pre-loaded within the tube to ensure the sample can be read properly. However, failure to slowly invert the tube several times after the draw may result in the additive not mixing enough with the blood, leading to inaccurate test results. Note that tubes should not be mixed vigorously; this can lead to hemolysis and sample rejection.

LabTAG by GA International is a leading manufacturer of high-performance specialty labels and a supplier of identification solutions used in research and medical labs as well as healthcare institutions.

Reference:

1. The Problem of Mislabeled Specimens. Northfield, IL; 2010.
2. Ernst DJ, et al. Labeling tubes before collection threatens patient safety. Ann Blood. 2018;3:16.
3. wan Azman WN, et al. Hemolyzed Specimens: Major Challenge for Identifying and Rejecting Specimens in Clinical Laboratories. Oman Med J. 2019;34(2):94-98.
4. Lima-Oliviera G, et al. Incorrect order of draw could be mitigate the patient safety: a phlebotomy management case report. Biochem Med (Zagreb). 2013;23(2):218-223.