Blood gas: A brief anecdotal history by one who has been there

Sept. 1, 2012

Consider the evolution of blood gas technology. Having started in the laboratory instrument industry in the early 1980s, I have had the opportunity to see the blood gas instrument evolve from what was once a very temperamental and not-so-user-friendly instrument, to a very simple, easy-to-use instrument.

In the beginning there were really only four major original equipment manufacturers (OEMs) of instruments to test for blood gases: Corning (now Siemens), Instrumentation Laboratories, Nova Biomedical, and Radiometer. While these four major manufacturers still exist, now there are many others worldwide.

Also, a generation ago, although these instruments were considered lab instruments, they were primarily used in the Respiratory Therapy departments of most hospitals. Since the respiratory therapists were not lab techs, it was extremely difficult for them to work with already temperamental instruments. These instruments were very large, which also complicated the job of the respiratory therapist. In order for an arterial blood sample to be accurate, it should be analyzed within 10 minutes of sampling from the patient. Thus the therapists needed to get to their instrument quickly after taking the patient sample. This could sometimes be difficult if the sample was being drawn in the emergency room, or worse in surgery. If the instrument was having a bad day, then so was the respiratory therapist.

Then came an advance:  A new point-of-care (POC) method of testing blood gases with a cartridge-based technology allowed the clinician to run the necessary test bedside. At the time, the technician would need to insert a cartridge for each test. That could prove costly for the hospitals. At about this time, many hospitals moved their stand-alone blood gas instruments under the direction of the lab directors. Blood gas instruments were also subject to Clinical Laboratory Improvement Amendments (CLIA) regulations. However, for a time the I-Stat and other POC instruments were CLIA-waived.

Many hospitals today utilize the POC instruments, in conjunction with stand-alone instruments, to verify the results provided by the POC instruments. Today’s blood gas instruments are less temperamental and much easier for the trained clinical laboratory professional to use.

The older stand-alone instruments allowed hospitals more versatility, in that they use reagents, combined with membrane electrode technology, and can perform more tests more quickly. The older systems were open analyzers that allowed the hospital to explore alternatives to the OEMs for purchasing the consumables needed to run the instruments—for example, electrodes, reagents, and quality controls (QC). This could save laboratories as much as 50% of the OEM consumable cost. For a large hospital, this can amount to considerable savings.

Today, the OEMs manufacture closed systems, either by installing programmed barcode readers that only allow their reagents, bottles, and electrodes to be used on their instruments or by creating reagent/sensor cartridges that allow only a specific number of tests to be run.

However, there are still opportunities for laboratories to save on consumables, even with closed cartridge-based systems. Other companies specialize in the manufacturing of alternative blood gas reagents, electrodes, and quality control. Although their electrodes and reagents can be used only for specific instrumentation, their quality controls are assayed for all Blood Gas/ISE instrumentation. Many OEMs provide a quality control pack with their instruments; however, alternative manufacturers can offer an opportunity for the lab to look for additional savings without interrupting their current contract with the OEMs for consumables.

Both stand-alone and POC instruments are now subject to CLIA regulations. The hospital or laboratory is required to perform QC on a daily basis throughout the day according to the standard operating procedures. In addition to the daily QC, any laboratory that carries out moderately complex tests is required to perform calibration verification (CV) on its instrument. The laboratory is required to perform CV at least twice per year, for documentation purposes, and also whenever the following events occur:

  • After any major preventative maintenance, or when critical parts affecting an instrument’s performance are replaced
  • After a laboratory switches lot numbers on the reagents it uses in conjunction with an instrument
  • After a laboratory identifies an unusual trend or shift reflected in its control materials, or results that fall outside of established acceptable limits.

When the CV is performed, it is the responsibility of the lab director to maintain a regression analysis report, either manually or electronically.

Laboratories can obtain CV material from many sources; there are many variations of this material available, from lyophilized or liquid stable. All companies offering these products offer a data reduction service, though some may take up to five to seven days for your report to be returned.

In today’s economy, it is important for every laboratory to look at where it can save. With regard to blood gas instrumentation, opportunities to save on reagents and electrodes are getting more rare as instruments designed by the OEMs offer only one source for their consumables. However, quality controls and calibration verification are areas that lab managers should explore, in an effort to allow their facilities to meet tighter budgets.

Al Jordan is Vice President, Sales and Marketing, for Massachusettes-based Phoenix Diagostics, a manufacturer of consumables for Blood Gas, Electrolyte, Co-Oximetry, and Chemistry analyzers worldwide.  He has more than 28 years experience in the laboratory equipment and clinical diagnostics industry.