From the draw to the lab bench - how to add value at every stage of blood sample collection

Physician's order and role of blood collection staff

One of the first decisions a physician must make is which blood parameters need to be analyzed. Based on these requirements, the appropriate blood collection tubes are ordered. At this point, it is sometimes not considered which tube is the most suitable. This may be due to a lack of information about the patient, which is simply not available at this stage. Is a high-volume tube needed for the analysis or is a low-volume tube a better choice?

Is it a pediatric or geriatric patient and what are their vein conditions - will they even allow the collection of multiple high-volume tubes or will this cause problems during the collection process? Is capillary blood collection more suitable for the patient?

Ideally, all of these questions and more should be evaluated and answered before the order is placed. In practice, this is often not possible. However, it should then be an option for the frontline blood collection staff to use a different volume tube or collection technique if this is more likely to be successful and ensure high quality samples. To do this, staff need both the information about what is required as a minimum to carry out the analysis in the laboratory and the knowledge and authority to make this decision.

This means, for example, that in the case of difficult vein conditions, it is possible to switch from an originally requested high-volume tube to a low-volume tube if this improves the sample quality. If the reduced sample volume is suitable for analysis in the laboratory, it makes more sense to take this route than to insist on the high-volume tube at the expense of sample quality (e.g. due to collapsing veins¹), which may result in the sample being rejected by the laboratory.

Choice of blood collection products

Another aspect to consider is the availability of the required blood collection products. The ability to select the most appropriate product for the individual patient's blood collection needs can make all the difference. A blood collection professional will always consider the patient’s overall and vein condition to select the right combination of products and tubes.

For example, a healthcare professional would take into account that in the case of poor venous blood flow, e.g. in geriatric patients, high-volume tubes would be avoided if possible, as the vein could be drained by the high vacuum and the needle of the blood collection device could attach to the inner wall of the vein and blood flow into the tube stops¹. In practice, this can lead to underfilled tubes if the person performing the draw is not aware of this correlation. The underfilled tube can lead to rejection by the laboratory or be the cause of inaccurate data, as the additive to blood ratio in a tube with additives will not be correct. Ultimately, this will lead to delays if another sample has to be requested and drawn, or even to inadequate patient treatment.

Blood sample handling and transport

The fact that a high-quality sample is collected on-site does not necessarily mean that it will remain of high quality when it arrives at the laboratory. Proper handling and transport after collection is key to maintaining the quality. This includes the gentle inversion of the blood sample containing tubes according to the instructions for use. If multiple samples are collected, it is important to follow the correct order of draw to avoid any potential cross-contamination of additives in different tubes¹.

Proper labelling of the sample is necessary to avoid mix-ups or rejection in the laboratory. Using a digital solution with pre-barcoded tubes throughout the whole process can contribute to increase efficiency and traceability. Knowing exactly when a sample was taken, by scanning the barcode at the time of collection, gives insight into the TAT (turn-around-time) and helps to decide to reject samples if they have been stored for too long before arriving in the laboratory to avoid erroneous data.

Proper transport from the point of collection to the point of analysis also takes into account upright storage of tubes, stable temperatures, no excessive shaking and more. Advanced digital tracking systems can also include this type of transport information to give laboratory staff better insight and help them reject non-compliant samples before they are analyzed and use up resources.

The quality of a blood sample is essential not only for the laboratory, which must rely on it, but also for the physician who uses the results to decide on further treatment, and for the patient, whose wellbeing depends on it. All department managers, such as laboratory directors, should therefore keep an eye on the whole process to ensure maximum efficiency and the best patient outcome.