Reliability cannot be achieved in a clinical laboratory through the control of accuracy in the analytical phase of the testing process alone. There are many potential sources of errors as well within preanalytical phase. The preanalytical phase plays a crucial role in laboratory diagnostic and blood collection is probably its most important aspect.
Awareness of pre-analytical variables is the key to identify potential gaps in quality and assurance of diagnosis and treatment. The application of quality systems to laboratory testing requires total quality management throughout the laboratory process and on-going process of continuous improvements. That is why adoption of both plasma (as better type of specimen) would improve specimen quality, decrease TAT, and optimise lab testing process in general at King Hussein Cancer Center (KHCC).
Heparin plasma and serum are commonly used matrices. Serum is the preferred specimen for the analysis of biochemical parameters, however plasma has some important laboratory advantages like a shorter turnaround time (TAT) due to both the absence of the 30-60 minutes time interval needed for the coagulation process and to a shorter centrifugation step and allows to obtain a larger volume of sample (about 15-20 per cent more) which increases the number of analysis that can be made on one sample.
According to the World Health Organization, plasma is preferred to serum because it reflects better the patients’ physiological condition by preventing the changes induced by the coagulation process which causes an increase in some analytes (e.g. potassium) and a decrease of others (e.g. total proteins). In addition, the use of anticoagulant prevents the variations induced by the coagulation factors activated when the needle is inserted. The use of plasma also minimises the formation of fibrin networks found very frequently in serum tubes for several reasons: the sample arrived quickly in the laboratory (e.g. through pneumatic mail systems) and is centrifuged before clot formation, or because the sample was from patients taking oral anticoagulants or heparin which delayed the formation of the clot.
The presence in serum of soluble fibrin clots causes, on highly automated analytical lines, frequent sampling alarms requiring re-centrifugation or manual re-run of the sample leading to a large increase of the TAT.
Blood collection tubes with a gel separator are often the preferred choice because serum (plasma) is physically separated from clotted whole blood (blood cells). However, some drawbacks may still occur like the non-specific adsorption of the molecule to be analysed or the release of interfering substances. A new blood collection tubes, BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes, containing lithium heparin as anticoagulant and an innovative mechanical separator has been recently developed. This newly developed BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes is a single-use, plastic blood collection tube with a sterile interior and a safety-engineered BD Hemogard™ closure.
The interior tube wall surface has a coating of Li-heparin anticoagulant, and the non-gel separator contains a surface coating of surfactant. The separator rests at the top of the tube and allows blood to pass through by its orientation. During centrifugation, the separator stretches and is launched into the blood column. The principle of differential buoyancy is used for proper positioning during centrifugation: an upward force exerted by the blood opposes the weight of the immersed separator.
Throughout the centrifugation process, channels are created around the stretched separator, allowing blood cells and fragments to sediment out of the plasma. When the centrifuge slows down, the separator returns to its original shape and forms a seal between the plasma (above) and blood cells (below), creating a stable and robust barrier. According to the manufacturer BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes will improve the quality of laboratory routine analysis in term of TAT and analytes stability.
Previously (before June 2020), in adult emergency department at KHCC (Amman, Jordan), blood collection procedures were performed for outpatients on a regular basis using serum gel tubes, plain tubes, EDTA, NaF and heparin tubes for Chemistry and Immunoassay testing. While there were some issues related to TAT, even if the department lacks a full tracking system to measure TAT, there was a noticeable delay and retesting due to sample rejections which, again have multiple origins (underfilled tubes, haemolysis, clotted samples, etc.). These causes of sample rejections were mainly due to lack of best practices but also the type of sample used (serum), which presents a challenge when it comes to respect to clotting time, not obvious in an emergency department, as well as fibrin, clots and gel globules that involve sample quality concerns and even instrument downtime.
For that KHCC facility has started to use a new tube called BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes, since June 2020. Considering its advantages of providing a better plasma quality with a unique separation technology, as well for the possibility to consolidate other tubes like heparin, NaF, plain and serum gel tubes in a single tube. In addition, there is a focus on the economic implications which will be a direct result of the advantages mentioned before (tube consolidation, improved turnaround time and sample quality).
In this study, our main objective is to highlight the main outcomes of implementing BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes regarding TAT, tube consolidation and sample quality. It is an observational retrospective study that compares the outcomes of the pre- and post-intervention of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes. In this study comparison needs to be done as below:
Pre-adoption phase: BD Vacutainer® SST II Advance (serum gel) tubes in use, July 1 to December 31, 2019
Post-adoption phase: BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes in use, June 1 to November 30, 2020
For each point of the study same aspects were measured and analysed to identify the impact of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes in three main aspects:
Tube consolidation impact of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes
Implementation of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes helped to consolidate almost all non-whole blood-based category of tests into same Lithium Heparin tube (including Lactic Acid, Parathyroid Hormone, Procalcitonin and Pro-BNP), decrease consumption of tubes with EDTA and Sodium Fluoride and reduce number of tubes from 3.29±0.98 to 2.14±0.96 and volume of blood from 14.98±3.53 to 6.87±3.29 ml collected from one patient through one venipuncture (Fig. 1).
BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes impact to TAT of blood collection
Adoption of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes led to decrease of total blood collection time from 147.16±40.85 to 118.35±41.13 sec (Fig. 2). Most time decrease was found for tube fulfilling with blood from 48.24±18.25 to 25.82±17.12 sec (Fig. 2) due to tube consolidation as mentioned above.
BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes impact to sample quality
Specimen quality was also improved following the adoption of BD Vacutainer® Barricor™ LH Plasma Blood Collection Tubes. There was decrease of specimen rejection and number of specimens with haemolysis and clots (Fig. 3). Implementation of the new Lithium Heparin tubes helped also to decrease number of specimens with wall-oriented clots which might form once tubes are kept in horizontal position during blood clotting time (at the blood collection point or during transportation by porters or through pneumatic tube system).
Thus, adoption of BD Vacutainer® Barricorâ„¢ LH Plasma Blood Collection Tubes at KHCC helped not only to consolidate non-whole blood-based category of tests into one tube and number of tubes and volume of blood collected from one patient through one venipuncture, but also decrease of specimen rejection rate TAT of blood collection procedure.Â
References available on request.
Maher Abedelmonem Mahmoud Sughayer is the Chairman, and Abeer Al-Nuirat is the Supervisor of Immunochemistry section and Laboratory Manager, of Pathology & Laboratory Medicine, Pathology and Laboratory Medicine Administration at KHCC in Jordan.
