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Please see our Blood Gas Analyzers section to find manufacturers that sell these products
Clinicians use blood gas analyzers to measure the level of arterial oxygen tension (pO2), carbon dioxide tension (pCO2), and acidity (pH) to assist them in disease diagnosis and treatment. The pO2 is an indication of the pressure of oxygen dissolved in the blood, and the ease of movement of oxygen from the airspace of the lungs into the blood. The pCO2 is an indication of the pressure of carbon dioxide dissolved in the blood, and the ease of movement of carbon dioxide out of the body.
There are several blood gas analyzers on the market that are suitable for measuring the basic blood gas panels in addition to measuring electrolytes and metabolites as an expanded scope for disease diagnosis and treatment.
Blood gas analysis methods
The use of ion selective electrodes (ISEs) is the most prevalent test method and is based on the measure of the concentration of ions through an ion selective membrane.
Optical fluorescence is a newer method. OPTI® analyzers from OPTI Medical Systems, Inc. (www.optimedical.com) rely on optical fluorescence from optical electrodes (optodes) calibrated for pCO2, pO2, and pH. The analyzer aspirates the blood sample into the cassette and across the optodes, and fluorescence emission is measured.
Blood gas analyzer purchasing considerations
Choosing a blood gas analyzer is a complex process. Numerous factors need to be considered, as listed below.
Types of analyzers
Handheld blood gas analyzers are for point-of-care testing, while benchtop analyzers are for point-of-care or laboratory testing as determined by their size and portability.
Representative handheld analyzers include the i-STAT® System from Abbot Point of Care (www.abbottpointofcare.com) and the epoc® Blood Analysis System from Alere, Inc. (www.alere.com).
OPTI analyzers from OPTI Medical Systems are one of the most suitable benchtop analyzers for point-of-care testing due to their smaller size.
Analytes measured
The majority of blood gas analyzers are able to measure a range of analytes in addition to the basic gas panel and pH. An analyzer that performs blood gas analysis only is the EasyBloodGas™ analyzer from Medica Corp. (www.medicacorp.com).
Sample size
Sample size is an important consideration for blood and reagent conservation. Handheld analyzers generally work with a smaller sample size. The i-STAT System and the epoc Blood Analysis System have a sample size of less than 96 μL.
A benchtop analyzer with a smaller sample size is the Stat Profile® pHOX® analyzer from Nova Biomedical (www.novabiomedical.com) with a blood gas panel sample size of 45 to 60 μL.
Sample handling
Blood gas analyzers utilize single- or multiuse cartridges, each having their benefits such as flexibility, sample integrity, and maintenance-free use. Analyzers that feature a single-use cartridge include the i-STAT System, the epoc Blood Analysis System, and the ITC benchtop IRMA TRUPOINT® Blood Analysis System (www.itcmed.com). Analyzers with multiuse cartridges include the GEM® Premier analyzers from Instrumentation Laboratory (www.us.instrumenationlaboratory.com).
Clot protection
Clots can cause analyzer problems, and clot protection is an important consideration. The cobas b 123 POC and cobas b 221 systems from Roche Diagnostics (www.roche.com) offer a clot protection system.
Throughput and analysis time
A high-volume hospital may require high throughput and, in some clinical settings, analysis speed is as important as a high-throughput rate.
Stat Profile pHOX analyzers from Nova Biomedical offer throughput of 50 samples/hr. The Stat Profile pHOX Ultra analyzer gives up to 20 critical care samples in 2 min.
The Stat Profile Prime® analyzer from Nova Biomedical offers simplified critical care testing. This analyzer relies on the ZERØTM maintenance cartridge technology for a smaller, faster, and less expensive critical care analyzer. This cartridge technology comprises individual cartridges for biosensors, calibrators, and liquid quality control.
Automation
Automated calibration allows for long periods of intervention-free operation. The GEM Premier 4000 with PLUS technology from Instrumentation Laboratory offers complete automation quality management.
Data management
Low-throughput machines display results on screen and may have a connect printer. For testing facilities where throughput is important, data management software and interface connectivity become important as well.
The GEM Premier line has real-time wireless upload capability, and GEMweb® Plus Custom Connectivity allows access and control from any networked PC or Gem Premier 4000 analyzer.
Analyzers from ITC have interface connectivity through RALS®-Plus, Aegis POC™, PrecisionWeb®/SYBASE®, and TELCOR QML®, and a data management system through Hemochron® Report Maker.
Operating costs
The purchase price and the device warranty are important considerations in selecting an analyzer. Once an instrument is selected, operating costs such as the cost of reagents, the maintenance schedule, and the time required for recalibration come into play.
Representative blood gas analyzers
- Abbott Point of Care: i-STAT System, which measures pH, pCO2, pO2, electrolytes, and metabolites.
- Alere, Inc.: epoc Blood Analysis System, which measures pH, pCO2, pO2, electrolytes, and metabolites.
- Instrumentation Laboratory: GEM Premier 3000, 3500, and 4000 analyzers, which measure pH, pO2, pCO2, electrolytes, and metabolites.
- ITC: IRMA TRUPOINT Blood Analysis System, which measures pH, pCO2, pO2, electrolytes, and metabolites, and offers the AVOXimeter® 1000E and 4000 as separate analyzers for the performance of co-oximetry.
- Medica Corp.: EasyBloodGas analyzer, which measures pO2, pCO2, and pH, and EasyStat analyzer, which measures pO2, pCO2, pH, electrolytes, and hematocrit.
- Nova Biomedical: Stat Profile Prime analyzer, which measures pH, pCO2, pO2, sodium, potassium, calcium, chlorine, glucose, and lactate, and Stat Profile pHOX analyzers, which measure pH, pCO2, and pO2. The Stat Profile pHOX adds hematocrit and hemoglobin; the Stat Profile pHOX Plus adds glucose, sodium, potassium, and chloride or ionized calcium; the Stat Profile pHOX Plus C adds chloride and ionized calcium; the Stat Profile pHOX Plus L adds lactate; and the Stat Profile pHOX Ultra adds ionized magnesium.
Table 1 – Blood gas analyzer providers
- OPTI Medical Systems: OPTI R and OPTI CCA-TS2 analyzers. The OPTI R measures pH, CO2, pO2, total hemoglobin, SO2, sodium, potassium, and ionized calcium, and the OPTI CCA TS adds glucose and urea nitrogen.
- Radiometer America Inc. (www.radiometeramerica.com): ABL80 FLEX, ABL90 FLEX, and ABL800 FLEX analyzers. The ABL80 FLEX and ABL90 FLEX are suitable for low-, medium-, and high-volume testing sites. The ABL80 FLEX measures pH, pCO2, pO2, hematocrit, electrolytes, metabolites, and co-oximetry. The ABL90 FLEX measures pH, pCO2, pO2, hemoglobin, electrolytes, metabolites, and co-oximetry. The ABL800 FLEX is the largest of the three analyzers and is suitable for medium- to high-volume testing sites and measures pH, pCO2, pO2, hemoglobin, electrolytes, metabolites, and co-oximetry.
- Roche Diagnostics: cobas b 123 POC and cobas b 221 systems. The cobas b 123 POC system measures pH, pCO2, pO2, hematocrit, electrolytes, and metabolites, and the cobas b 221 system measures pH, pCO2, hematocrit, hemoglobin, electrolytes, metabolites and hemoglobin, bilirubin, and pH pleural fluid.
- Siemens Healthcare Diagnostics Inc. (www.siemens.com): The RapidLab® 1200 systems measure pH, pCO2, pO2, electrolytes, metabolites, and co-oximetry. The RapidPoint® 300 system with the smallest footprint measures pH, pCO2, pO2 (340, 350) and electrolytes, and hematocrit (350). The RapidPoint 400 systems measure pH, pCO2, pO2, electrolytes, metabolites, and co-oximetry. The RapidPoint 500 systems have the same menu as the RapidLab 1200 systems.
Going forward
As analyzers are becoming physically smaller with enhanced functionality, expanded menus, and integrated and automated quality control features, the expected continued focus of blood gas analysis technology is on testing at the point-of-care.
Providers
A list of providers of blood gas analyzers is in Table 1.
Please see our Blood Gas Analyzers section to find manufacturers that sell these products
Lina Genovesi, Ph.D., JD, is a Technical, Healthcare, and Business Writer based in Princeton, NJ; e-mail: [email protected] ; www.linagenovesi.com