By Jan Hodnett, MS, MT(ASCP)

Blood gas and electrolyte testing continue to grow

Labs love it or live with it, but point-of-care testing for critical care is among the fastest growing segments in the laboratory. Today, point-of-care blood gas and electrolyte testing is the standard of care. Two-thirds of all blood gas/electrolyte testing is performed outside the main lab — in satellite labs or by handheld analyzers, according to Irving, Texas-based CaseBauer, a research and consulting firm.

Market Share of Blood Gas & Electrolytes Manufacturers

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SOURCE: 2001, Enterprise Analysis Corp., Stamford, Conn.

For 10 years, blood gas/electrolyte testing has been shifting to “satellite” labs in emergency departments (ED), operating rooms and ICUs. Approximately 65 million blood gas/electrolyte test panels are performed each year in the United States, representing $260 million in revenue to IVD manufacturers, according to CaseBauer. Handheld blood gas/electrolyte testing is growing at an astounding 30 percent per year.

In its 2001 U.S. Hospital Point-of-Care Survey released in June, Enterprise Analysis Corp. of Stamford, Conn., surveyed 584 hospitals and found that they had an average of 3 point-of-care testing categories in 2001 versus 2.3 in 1999. The growing acceptability of POC testing is reflected in sales trend data. For example, 414 of 584 hospitals anticipate purchasing POC products over the next year.

Among the market share leaders in the point-of-care blood gas/electrolyte testing area, according to Enterprise Analysis, are I-Stat (Abbott Diagnostics), Diametrics, AVOX, Bayer Diagnostics, Instrumentation Laboratories, Nova Biomedical, Radiometer America and AVL (Roche Diagnostics). EAC’s research indicates a 50 percent penetration for point-of-care handheld blood gas/electrolyte testing, while the overall penetration for point-of-care cardiac marker testing is still very small, only about 4 percent. The more significant fact, according to the EAC survey, is that the total number of sites using point-of-care cardiac marker testing increased from 4 in 1999 to 25 in 2001, representing more than a six fold increase. Market share leaders in point-of-care cardiac testing, according to EAC, are Biosite Diagnostics, Dade Behring, Spectral Diagnostics and Roche Diagnostics.

In addition to figuring market share break down, EAC surveyed users on their satisfaction levels with point-of-care vendors. That information is available in a report ($500), which is tailored for hospital personnel involved in making a POC purchase decision.

Focus on stat testing
“Nova virtually created the POC market in 1978, when we launched the first whole-blood automatic Na/K analyzer, and again in 1985 when we introduced the first combined blood gas and electrolyte analyzer.” said Lloyd Adams, director of marketing and business development at Nova Biomedical in Waltham, Mass. “Nova has consistently focused on whole-blood stat testing. Today, we have the broadest stat whole-blood test menu available.”

Percentage of Hospitals with POC
Instruments by Discipline

(Does not include satellite labs or glucose testing)

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SOURCE: 2001, Enterprise Analysis Corp., Stamford, Conn.

Nova offers 11 whole-blood or serum electrolyte analyzers to which a 40-position turntable can be added for high-throughput testing. Also offered are two blood gas analyzers: the traditional Stat Profile M line, with the broadest test menu of any blood gas/electrolyte system, and the Stat Profile pHOx analyzers, with automatic quality control, built-in oxygen saturation (SO2) and hemoglobin channels.

Placed on mobile carts, Nova analyzers are designed for moving from location to location, as needed. Rather than go to the bedside, they are usually found in a satellite or ED lab, and the sample is brought to the analyzer.

“Unfortunately, POC data sometimes does not get back to the laboratory,” Adams said. “Any hospital with a satellite lab will have an LIS link and upload the data to the lab, but that doesn’t happen very often in ORs or patient care areas. A lot of data doesn’t get back to the LIS and probably doesn’t get billed.”

To help avoid this problem in the future, a consortium was established in 1990 to create an industry standard for data transfer to and from point-of-care analyzers. This Connectivity Industry Consortium (CIC), comprised of 52 organizations, recently released its connectivity proposals. Final review and balloting on the proposals ended in May. Once ratified, CIC will transfer the proposals to three standards development organizations (NCCLS, HL7 and IEEE) for publication and future development.

“Connectivity is probably the biggest request we have from hospitals right now,” Adams said. “Probably the most sought-after features are connectivity features so that the data is assured to go to the LIS, the HIS or both. The laboratory needs to keep records, and the hospital wants to make sure the test gets billed. Forty percent of our analyzers are purchased by departments outside the laboratory, but it works out better if they are bought by the laboratory, because the lab has more of an interest in quality control and data integrity,” Adams said.

Most hospitals today enlist a point-of-care committee with representatives from purchasing, nursing and the laboratory to make decisions on where POC analyzers should reside, who should use them and how to keep them in compliance.

A perfect correlation
Instrumentation Laboratory (IL) in Lexington, Mass., recently introduced its GEM Premier 3000 critical care blood gas analyzers, which Brian Durkin, executive director of sales and national accounts at IL, said is unlike other critical care blood gas analyzers. Its standardized platform allows for the use of up to 13 cartridge types. “Unlike other companies that have several products, we have one instrument, and you tailor the menu and the cartridge size to meet your institution’s needs,” Durkin said.

POC Cardiac Market Share – Weighted

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SOURCE: 2001, Enterprise Analysis Corp., Stamford, Conn.

“Depending on whether you want just blood gases or blood gases with electrolytes, there may be several instruments around the hospital. With the GEM, it’s the same instrument, and there are multi-use cartridges that slide into the side of the instrument. Depending on what you want to test, it’s always the same instrument; it’s only the cartridge that is different for blood gases, electrolytes or glucose/lactate,” said Durkin.

Durkin maintains that the GEM provides true standardization throughout the hospital. “For example, the hospital’s main lab may use the classic analyzer with electrodes and gas tanks, but down in the OR they may use a point-of-care analyzer,” Durkin said. “They GEM 3000 can operate throughout the hospital, in respiratory and the main lab, the surgical suite and ICU, so there is true standardization throughout the hospital. It provides perfect correlation. It’s always a sticky point with point-of-care when the POC sodium doesn’t match the one in the lab. It’s the first time that the values will match.”

The leader in handheld critical care
i-Stat also claims to have been on hand for the beside birth of point-of-care testing. “I-Stat provided the impetus for bedside blood analysis in critical care and continues to be the leader in that area,” said Craig Thompson, U.S. marketing manager for point-of-care testing at Abbott Diagnostics, which distributes the I-Stat. As the EAC survey indicates, I-Stat is the No. 1 U.S. market share leader in point-of-care blood gas/electrolytes testing.

Thompson defines point-of-care as the ability to perform a variety of critical-care stat tests at the bedside or in the operating room on a handheld platform that delivers accurate results within two minutes. Not surprisingly, that definition pretty well fits the I-Stat system. “The I-Stat 1 analyzer’s user-friendly handheld technology is important to the user, but it also incorporates state-of-the-art QA/QC features which are vital to the point-of-care program manager. The I-Stat system incorporates a broad menu with Abbott’s Precision Net data management system, which allows stat testing to be performed as it is requested. Results can be downloaded for review on a real-time basis.”

“Data capture is a real challenge for most point-of-care programs,” Thompson said. “If patient results and the operators performing those results are not tracked on a regular basis, it puts a significant strain on the people responsible for the point-of-care programs. The Precision Net System allows I-Stat operators to download results from the bedside to the program manager for review. This helps to maintain the highest level of quality assurance and quality control in the point-of-care program. It also allows the operator to spend less time performing manual data entry.”

“In the future, platform consolidation, platform miniaturization and a more expansive test menu will be key steps in the evolution of bedside critical care testing,” Thompson said. “In addition, connectivity solutions such as wireless technology and positive patient identification will be at the forefront of Abbott’s point-of-care strategy. We see point-of-care testing as a rapidly expanding area that has not seen its true potential yet.”

Cardiac POC – changing therapy on the spot
About 60 percent or more of the cardiac enzyme testing for chest pain patients is still performed on instrumentation based in the main lab, according to Chris Wayne, director of marketing and consulting services at Spectral Diagnostics USA. He adds however, “testing is clearly moving into both point-of-delivery and point-of-care, all in an effort to expedite the time frame for results and subsequent treatment.”

No discussion of point-of-care, cardiac testing would be complete today without mentioning the impact of the guidelines on chest pain management recently released by the American College of Cardiology and the American Hospital Association.

“The ACC/AHA guidelines on the management of chest pain are the biggest factor affecting the growth of this area,” according to Wayne. “Most — seven out of every 10 — chest pain patients are ruled out for an MI. Most chest pain is not cardiac-related; however, finding patients whose chest pain is of cardiac origin is determined largely by cardiac enzymes. Since the guidelines came out in September 2000, there has been a significant focus on the time frame in which those cardiac enzymes are returned. The guidelines on enzyme testing have indicated a preference for 30 minutes or less, not just in lab “turnaround” time but in “request-to-result-in-hand” time, which is difficult for any core lab to meet. This area has seen a lot of growth and will continue to see growth,” said Wayne.

The need for quick clinical decision-making is particularly critical with respect to cardiac enzymes. A positive troponin, the new gold standard, may indicate myocardial cell necrosis. The longer it takes to recognize that and institute treatment, the poorer the outcome. Troponin, a complex molecule, is more difficult to detect than myoglobin or CK-MB. Furthermore, there is no industry standard for a quantitative value for troponin.

Many cardiologists believe that a numeric value is not necessary for an initial disposition decision with a troponin test, because risk stratification is the immediate goal in the emergency department. “Thus, we went with a qualitative platform,” said Wayne. “Another reason is its simplicity. Something used right at the bedside has to be simple. What good is knowing a patient has a micro-amount of troponin if it takes an hour and a half to get the result back?”

Besides troponin I, Spectral’s cardiac STATus handheld panel test detects CK-MB and myoglobin. “Our product requires no instrumentation or refrigeration; it’s truly a stand-alone device. It doesn’t require a cartridge that you have to marry to another device or instrument, and it can be done at the bedside or in the lab,” said Wayne. “There are many other platforms, many of which are good, but they should be considered with your objectives in mind.”

POC and cost
POC testing is often more costly per reportable result than testing in the main lab, but obviously there are other factors to consider. “The trick is weighing whether that increased cost is worth the clinical and efficiency benefits,” said Wayne. “Often, not all costs are considered. If a POC test allows a physician to make a disposition decision that can expedite that patient to the right level of care or perhaps discharge a patient that doesn’t need to be there, then the savings downstream are far more significant than any POC cost-per-reportable result difference. You have to consider what will be done differently if the result is made available faster.”

The POC market is growing — and it is here to stay. In its 2001 survey, Enterprise Analysis Corp. found increases in all categories of point-of-care testing since their previous survey in 1999. The number of point-of-care test categories performed in each hospital also is growing.

“It is an understatement to say that the lab plays an important role in any critical care testing,” Wayne said. As critical care testing becomes more prevalent, he noted, laboratorians and vendors should make other departments aware of the importance of the lab’s role in moderately complex testing. “The lab has to be involved, and it’s important to have someone to facilitate that. We all need to work together,” he said.

Jan Hodnett is a freelance writer in Rye, N.Y.