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Due to safety concerns, closed-tube sampling (CTS), also known as cap piercing, has been a standard feature on hematology analyzers for a long time. But in recent years, CTS has been adapted for chemistry analyzers and is available on integrated workstations, such as the UniCel DxC 880i by Beckman Coulter Inc. (Fullerton, CA). The benefits of CTS are arguably more profound in chemistry testing than hematology testing because it addresses a broader range of issues, such as sample integrity and lab technologist safety. CTS can also improve work-flow efficiency, particularly in high-volume labs, by eliminating time spent on manually decapping and recapping test tubes.

Labs that have instruments without CTS often rely on unsophisticated and dangerously puerile methods to track test tubes and their caps during analysis. In some cases, this process involves lab technologists placing caps sequentially on an elaborate bingo card according to a number or color, and then tracking in reverse to match a cap with a tube after analysis. For technologists who have to focus on the order of the caps and tubes, the process can be tedious and frustrating, and they may experience caps affixed too tightly or might catch a gloved finger in a tube during recap.

For such reasons, manually decapping and recapping tubes can be harmful to both lab technologists and samples, creating a tenuous situation in which test results can be compromised and the patient’s safety is at risk. Maintaining sample integrity is another key benefit of CTS. By minimizing manual handling of samples, contamination risk is likewise reduced.

Adding Value

As an option on Beckman Coulter’s chemistry analyzers and a standard feature on integrated workstations, CTS is an integral, fundamental component of the lab instruments and analyzers, and not an add-on piece of equipment. With the technology built into the analyzers, labs can eliminate the manual decapping and recapping steps in the testing process without having to purchase a separate piece of equipment for the task.

Furthermore, annual cost savings can reach more than $30,000 by automating this repetitive process.¹ Much of the savings are derived from the prevention of repetitive motion injuries, a measurable risk in nonautomated labs that are facing the double threat of dwindling labor pools and surging workloads. But savings also come from the new flexibility available to lab technologists who were once burdened by the time-consuming task of decapping and recapping. With CTS, they are able to add value in other aspects of the lab, all of which will improve turnaround times and overall patient safety.

As laboratories are expected to do more with less, applying CTS in chemistry testing can achieve quantifiable improvements in work-flow. CTS also improves patient safety by minimizing the risk of sample error due to poor sample handling, and allows technologists to add value in other parts of the lab. In short, when applied to chemistry analyzers, CTS enhances human benefits by minimizing human error.

How CTS Works

Figure 1. (click to enlarge) Close up of a closed-tube sampling unit by Beckman Coulter Inc. (Fullerton, CA). The internal location of the unit on UniCel DxC chemistry analyzers and UniCel i class integrated chemistry and immunoassay systems facilitates lab safety and sample integrity during analysis.

On Beckman Coulter’s instruments, CTS occurs at the start of the testing process (see Figure 1). Laboratorians load the sample tubes onto the chemistry or integrated chemistry/immunoassay analyzer as usual. The tubes are sent to the CTS component and are automatically positioned under a cap piercer blade. The cap piercer can detect if a cap is present. If the tube is open or the cap is already pierced, the blade will not descend.

If a cap needs to be cut, a z-shaped blade pierces the rubber cap, creating a resealable incision. The blade lowers just enough to pierce the cap without touching the sample. The process is precise and controlled entirely by the instrument with no operator involvement. The cap piercer also features a wash tower where the blade receives a power wash after each cut, minimizing any carryover contamination.

After the cap is pierced, the tube is processed like any other sample. The sample probe passes through the z-cut and aspirates the sample. Immediately after aspiration, the z-cut reseals to prevent any leaking. Both closed tubes and open tubes follow the same testing process on the analyzer. Other than creating the z-cut on closed caps, the analyzers do not distinguish between open and closed tubes.

On integrated workstations, CTS is an integral first step, facilitating the function of the closed-tube aliquotter by allowing the sample to be aliquotted while the tube is capped. For example, on the UniCel DxC 880i, the closed-tube aliquotter routes the aliquot to the immunoassay side of the work cell while the original tube is routed to the chemistry side.

As with hematology analyzers, when the CTS technology is incorporated on a chemistry analyzer or an integrated workstation, it requires minimal maintenance. Roughly 30,000 pierces can be performed before a CTS component needs to be replaced, which equates to a replacement every two months for labs that run less than 500 samples daily.

Furthermore, CTS eliminates the need for any manual intervention, which is necessary even on stand-alone decapping workstations. With these devices, laboratorians have to return to the unit to retrieve and deliver tubes to the correct analyzers, which undermines efficiency.

Improving Worker Safety

Improving worker safety is one of the primary benefits of CTS because the technology eliminates manual processes that put staff members at risk of repetitive-motion injuries and biohazard exposure.

The twisting motion of manually decapping and recapping tubes can cause one of the most common repetitive motion injuries: carpal tunnel syndrome.² If a laboratorian develops carpal tunnel, recovering from it can be difficult. According to the U.S. Department of Labor’s Occupational Safety & Health Administration (OSHA), carpal tunnel syndrome results in employees missing more work days on average than other work-related repetitive injuries. The median number of days missed is 25, and some employees experience permanent disability.³

In addition, surgery is not always a viable solution. The CDC’s National Institute for Occupational Safety and Health reports that only 23% of patients who undergo surgery for carpal tunnel are able to return to their previous professions following the operation. By eliminating one of the root causes, CTS helps to lower the risk of laboratorians developing carpal tunnel syndrome.

Biohazard exposure is another serious concern. While accidents in labs are not common, they can be serious. Data gathered through 2001 by AVERT (West Sussex, UK) showed that 16 clinical laboratory workers reported known occupational HIV infections. Another 17 laboratorians contracted HIV or AIDS, and their only risk factor was having worked with patient specimens. The organization concluded that clinical laboratory workers had one of the highest incidents of documented occupational HIV infections, second only to nurses.⁴ CTS eliminates the key risk of manually handling tubes when samples can be spilled.

Moreover, from accidental splashes to aerosol leaks to broken sample tubes, the opportunity for biohazard exposure exists in every lab. A report from the Department of Pathology and Laboratory Medicine at Tan Tock Seng Hospital (Singapore) examined lessons learned from the severe acute respiratory syndrome (SARS) outbreak several years ago. The report noted that CTS on chemistry analyzers is one safety measure that labs can take during the analytical process to improve the safety of the laboratory environment and reduce technologists’ exposure to biohazards.⁵

Reducing Stress

From work backlogs to phones ringing nonstop and new batches of urgent tests, many factors can increase stress in the lab. Repetitive manual tasks fall into this category, and can cause stress by adding time and extra steps to the testing process.

Capping sample tubes is no exception. While manual decapping and recapping may not seem like a time-intensive activity, removing a cap and preparing a tube for testing can take 5-10 seconds. On the back end, recapping a tube for storage takes another 5-10 seconds. The time spent on decapping and recapping quickly adds up, particularly if a large number of tubes require immediate attention. For lab technologists who are already pressed for time, it is yet another task that must be completed.

Automating the process not only reduces one source of stress but also redirects the staff’s energy to other activities that require their knowledge and judgment, such as interpreting abnormal test results. According to one study conducted by Beckman Coulter, CTS can save 325 hours per year for lower-volume labs that process 117,000 tubes annually; 487.5 hours per year for mid-volume labs that process 175,500 tubes annually; and 650 hours for high-volume labs that process 234,000 tubes annually.¹ This time can be dedicated to reducing the testing backlog, consulting with physicians, or focusing on results that require further analysis and knowledgeable human insight.

The cap-piercing process itself is fast, with the lab analyzers requiring only a few seconds to position the sample tube and make the incision. Because this step occurs onboard the instruments and does not require manual intervention, overall turnaround time is reduced. Ultimately, more-efficient work processes lead to a less stressful working environment, another human benefit of CTS.

Assuring Confidence in Results

Patient safety is at the forefront of every lab’s mission, and it is also an important issue for hospitals. But in any laboratory, manual steps introduce risks.

Decapping and recapping sample tubes is one example. By eliminating the need to decap and recap tubes manually, CTS offers an automated way to ensure that the specimen caps remain firmly affixed to the tubes at all times. Specimens are not transferred from tube to tube, a manual step that opens the door to sample misidentification errors. There is also no exposure to evaporation or spillage, the latter of which could require a phlebotomist to draw another sample from a patient.

In addition, CTS greatly minimizes carryover because the z-blade only extends far enough to pierce the rubber cap. An analysis recently examined carryover of CTS samples versus open tubes that were loaded onto an instrument and did not have caps pierced. The analysis looked at carryover of sodium, potassium chloride, creatinine, calcium, total protein, albumin, ammonia, amylase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactic dehydrogenase (LD), lipase, total bilirubin, and uric acid. The results showed no significant difference in carryover. Any differences observed were not clinically significant and were well inside the claimed within-run imprecision of the assays.

With laboratories providing up to 80% of the information that doctors use to make medical decisions and diagnoses, labs must establish multiple lines of defense against errors. CTS is one additional line of defense and gives lab technologists confidence that they are providing the highest quality test results possible.

One Lab’s CTS Experience

Figure 2. (click to enlarge) Closed-tube sampling has been incorporated into UniCel DxC chemistry analyzers and UniCel i class integrated chemistry and immunoassay systems by Beckman Coulter Inc.

The experiences at the University of Missouri Health Care (Columbia, MO) provide insights into how CTS can be introduced and used in a laboratory. Three years ago, the hospital’s laboratory decided to implement new systems for chemistry and immunoassay testing. The lab knew that CTS was available on integrated chemistry/immunoassay testing platforms, which became one of its top priorities for the new instrumentation. The laboratory eventually chose the UniCel DxC 600i by Beckman Coulter, an integrated chemistry/immunoassay system that includes CTS and a closed-tube aliquotter (see Figure 2).

When the system went live, laboratorians had to get used to new ways of working, and old habits were difficult to break at first. Overall, the lab’s transition to CTS was smooth with no resistance from its staff. In fact, the lab technologists were eagerly awaiting the CTS technology because it would eliminate various manual steps. For example, instead of aliquotting the samples and loading them onto multiple instruments, the technologists could load the samples onto the analyzer, and the closed-tube aliquotter would automatically create an aliquot. The tubes would then be routed to the proper side of the system, depending on which tests were ordered.

Since introducing the CTS technology, the laboratory has experienced benefits ranging from a safer working environment to reduced costs and faster turnaround time. Because caps stay on, lab technologists do not have to worry about biohazard exposure, and they no longer need to take preventative steps such as working behind protective shields or gauze. The technology also helps to reduce the risk of repetitive-motion injuries in the laboratory and improves patient safety by eliminating the possibility of errors during aliquotting.

Costs have also been eliminated due to CTS. Before CTS, the laboratory regularly purchased large volumes of stoppers and corks to recap tubes after testing. Such purchases are no longer the case since the caps remain firmly affixed to sample tubes.

In addition, prior to introducing CTS, the laboratory required a minimum of three to four technologists to handle the instrument testing and manual work, including aliquotting and decapping and recapping sample tubes. The laboratory now requires only two technologists to oversee the testing, allowing others to focus on more value-added work. Moreover, the laboratory has not experienced service or reliability issues with CTS, and maintenance has been minimal.

Since installing its DxC 600i instruments, the laboratory has been able to offer more tests in-house, which has lead to an increase in testing volumes. With CTS, the lab is better positioned to absorb this additional testing. The overall process is faster and more streamlined, which helps the laboratory deliver test results when they are needed.

James Rigo is director of strategic marketing in the Chemistry Systems Business Center at Beckman Coulter Inc. (Fullerton, CA). He can be reached at jrigo@beckman.com.

Conclusion

From greater flexibility with staff time to improved work flow, CTS delivers benefits that improve day-to-day operations across the lab. The risk of errors is reduced, turnaround times are improved, and lab technologists know they are delivering better patient care.

Laboratories that have instruments with CTS also send a clear message about what they value, which is they are serious about investing in their people and processes, and they place a priority on protecting worker and patient safety. This message can help retain current staff and attract new talent as well.

CTS has transcended the boundaries of hematology testing to deliver new and different benefits to chemistry and integrated chemistry/immunoassay testing. The return on this technology is no longer limited to safety benefits. It has expanded to include efficiency and cost savings as well. As laboratories struggle to do more with less, CTS is one solution that helps streamline work, eliminate repetitive tasks, and reduce the risk of human error. The net result is a better human experience, from improved working conditions in the laboratory to high-quality results that enhance patient care.