I Want It Now!

Stat testing will never fall by the wayside, but its handling has undergone significant change. Stat-testing menus have expanded at the same time that some central laboratories have become so efficient that stat tests do not require special handling because all samples are turned around within stat-testing time guidelines. Other laboratories have implemented comprehensive point-of-care systems that provide urgently needed results at or near the patient’s bedside within an even shorter period of time.

Stat originates with the Latin statim, which means immediately. According to Duane Morris, COO of Response Biomedical Corp, Burnaby, British Columbia, regulations often demand that stat-test results be delivered within 30 to 60 minutes.

Ron Berman, vice president of automation and systems at Beckman Coulter Inc, Fullerton, Calif, estimates that about 60% to 65% of an average hospital laboratory’s testing is performed for outpatients, with the remainder performed for inpatients. “Typically, there are a lot of stats in that remaining 35%. How does the laboratorian prioritize?” Berman asks.

Guidelines, protocols, instrumentation, and software help meet the stat-testing demands of clinical laboratories. Manufacturers are constantly pushing to reduce turnaround times for their diagnostic products and to deliver more useful information that can help physicians make treatment decisions.

Automation Options

Beckman Coulter’s recently released AutoMate 800 Sample Processing System permits users to place priority tubes in a special area, where they become the next tubes to be processed. “This allows the lab to have a process to manage tubes as they come in, but also a method to prioritize tubes that need special attention,” Berman says.

Other automated features include sample loading and sorting; programmable, on-demand centrifugation; sample-volume detection (through the label); a decapper module; and intelligent aliquoting and tube labeling. Removing the manual factor from these steps helps to reduce errors and improve turnaround times.

Berman notes that all of Beckman Coulter’s analyzers offer some method for handling stat samples, though these methods may differ from an engineering standpoint. The Power Processor automated sample processing system permits the operator to stop routine processing at the push of a button and manually initiate stat specimen processing. A chemistry analyzer pushes routine racks back to make room for a stat rack, also at the push of a button; hematology instruments can aspirate stat samples manually.

“There are all sorts of ways within software to be able to say, ‘Pause what you are doing, finish the chemistries, and put this stat tube ahead for processing,'” Berman says. Automation, combined with process-management improvement, means that customers no longer need to process samples in batches, nor even to differentiate between stat and routine testing: turnaround is fast and consistent.

In addition, middleware can track stat specimens, alerting laboratories to their presence as soon as they are ordered. “The lab will know it’s coming and can look for it,” Berman says. The specimen is added to the system’s running log, and an alert is sounded when time is running out or the results are ready. Beckman Coulter’s DL2000 Data Manager features an instant-message window in which the alerts are displayed.

“There is a big focus on automation, but how does it work in combination with middleware and software to help with the physical management of tubes and data management?” Berman asks.

All in the Cartridge

Data management can be even more challenging with point-of-care instruments if results are not stored and/or transferred to the laboratory information system (LIS) electronically. “Many point-of-care systems print the result on a piece of paper that disappears, so it is a challenge to know where those results are, who has run them, and if billing can match it to a patient or ordering physician,” according to Bill Manchester, group product manager of WW marketing, critical care, Instrumentation Laboratory (IL), Lexington, Mass. IL features a system that offers LIS connectivity, whether the instrument is placed in the central laboratory or in patient care areas such as the intensive care unit or cardiovascular operating room.

The GEM Premier 4000 whole-blood analyzer is designed to work in the clinical laboratory or in a remote area where it will still deliver laboratory-quality results. Its moderate complexity means that technologists are not required to run the device; properly trained individuals may do so. The system monitors performance through Intelligent Quality Management (iQM), a real-time quality assurance program.

GEMweb Plus is the integrated operating software for the GEM Premier 4000. It enables all connected GEM instruments and computers to gain remote access to the system, permitting real-time supervision and automatic transfer of results. Orders can be downloaded from the LIS or hospital information system, samples can be validated, reports can be accessed, troubleshooting can be done remotely, and authorized users can be permitted access.

Training takes about 20 minutes, according to Manchester. Users can include nurses, respiratory care practitioners, and perfusionists, in addition to technologists. The system is so easy to use because the work is performed using a disposable cartridge, which minimizes the necessary manual intervention for sample or control analysis.

“The fluidics of the system, the sampler, pump tubing, distribution valve, waste container, and process control solutions—everything that would be a piece of a traditional blood gas analyzer is in the cartridge,” Manchester says. He explains that the sample is inserted into the cartridge, where it is eventually run over a sensor card that performs the measurements. The unit also serves as the waste container and is designed for easy disposal. Manchester likens each replacement cartridge to a new analyzer.

Also, customers also can specify the test menu, so that resources will not be wasted on unneeded tests. The testing menu includes blood gases, CO-oximetry, electrolytes, glucose, lactate, metabolites, hematocrit, and pH. Xavier Nogue-Villa, IL’s product manager for commercial strategy for the GEM Premier 4000, notes that the system takes about 90 seconds to produce a result (60 seconds for coagulation data). “There is a clinical benefit, particularly during surgery, to having the information immediately,” Nogue-Villa says, comparing the turnaround time to an hour for results from a central laboratory.

Rapid Response

Morris believes that additional point-of-care challenges include accuracy, precision, and compliance with regulatory requirements. “Accuracy relates to how close the result is to the true result, which is difficult for some analytes (such as troponin, where there is no true result),” Morris says. “The use of whole blood, a common point-of-care specimen, challenges instruments in terms of precision, and typically, it does not match that found on an analyzer.”

Compliance is a third, and rather large, issue. “Nurses, physicians, and other hospital staff are not interested in running controls and providing documentation. They want self-maintaining equipment so they can concentrate on patient needs,” Morris says.

Point-of-care devices, however, permit that same staff to focus more immediately on patient needs by providing information that helps to determine what those needs are, often more quickly than would be possible using the central laboratory. Sometimes, simply the elimination of transportation time makes a valuable difference.

Response Biomedical’s RAMP system has unique features designed to address these limitations while offering a turnaround time of less than 20 minutes. The lateral-flow immunoassay system is composed of a portable fluorescent reader and single-use disposable test cartridges. The analysis incorporates the company’s RAMP ratio, calculated using data from the detection and internal-control zones. “This corrects for a multitude of variability that could be present otherwise, improving the system’s accuracy and precision over those that use absolute fluorescence,” Morris says.

The device also features built-in controls (both positive and negative) that prevent samples from being run if the controls do not meet the standards programmed by the laboratory. Incorrect operator technique will also prevent sample processing; the system senses when the timing signals are off, whether due to the operator or to the device. “In either instance, the instrument produces a good result or no result at all,” Morris says.

The result is also clear: a specific readout, rather than a line or color change. “No judgment is required on the part of the user,” Morris says. This ease of use contributes to the moderate complexity rating, which means that the device can have a variety of users, including nurses and technologists. The device has been approved by the FDA for use with three cardiac markers: troponin I, creatine kinase MB, and myoglobin.

Real Time PCR

Point-of-care examinations are particularly valuable for super-stat specimens, which David Persing, PhD, MD, chief medical and technology officer for Cepheid, Sunnyvale, Calif, notes are more urgent than simple stat specimens. “Is the result needed before the patient leaves the ED? With super-stat specimens, time is of the essence and transport is a major limiting factor, so it makes sense to have the test run close to the patient. Regular stat testing may make better sense to run through a central lab for economies of scale and efficiency,” Persing says.

The GeneXpert system (Cepheid, Sunnyvale, Calif) is a closed and fully automated system designed to provide real-time polymerase chain reaction results in real time.

Both models work, but Persing has noted a trend toward completing more urgent testing at or near the patient, even with tests as common as those used to detect methicillin-resistant Staphylococcus aureus (MRSA).

MRSA tests may not commonly be designated stat, but Persing notes that more MRSA testing can be expected to occur in different areas of patient care (such as admissions, where knowing the patient’s MRSA status is sometimes necessary before assigning a bed). “That is a stat-testing indication,” Persing says. Similarly, other tests also benefit from near-patient testing. The company’s Smart GBS test for group B Streptococcus (GBS), which was approved for use on the SmartCycler system, can be run where patients in labor are admitted and in obstetrical clinics.

The Smart GBS test is the first polymerase chain reaction (PCR) test to have received a moderate complexity rating, according to Persing. Both Xpert tests run on the GeneXpert system, which accepts the cartridges in which the samples and reagents are combined. The instrument performs the sample preparation, PCR, and amplification in about 70 minutes and is not batch dependent. This rapid turnaround permits new testing protocols. For instance, GBS guidelines suggest that the test be performed around the 35th to 37th week of pregnancy. Some women, however, will miss the appointment and will not have the test performed at all; others will take it too early.

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Persing has noticed a tendency to have the test run at an earlier stage. He says, “This can backfire, since there is less of a connection between the antepartum and intrapartum results. Studies show that the sensitivity of an antepartum culture for predicting intrapartum culture activity is roughly 50% to 60%. This means you are missing a lot of converted cases.” Stat-testing demands are increasing because many facilities are implementing intrapartum testing, which is accomplished at or near the patient, to provide the results within the useful time range.

The company also offers an Xpert test for enteroviral meningitis and has products in development for vancomycin-resistant enterococci and Clostridium difficile. “We have a lot of involvement in hospital-acquired infections because that is our main focus,” Persing says. The company aims to have PCR produce results in real time. What could be more stat than that?

Renee DiIulio is a contributing writer for CLP.