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Please check out our Point of Care Devices (POC Diagnostic Devices) section to find manufacturers that sell these products
Total hemoglobin concentration is said to be the most common laboratory test ordered in medical offices and hospital settings. It is used to determine the presence of anemia, functionally defined as insufficient oxygen-carrying capacity of the blood.
In keeping with the trend of incorporating sophisticated technology into easily used point-of-care devices, many manufacturers provide products that offer prompt assessment of hemoglobin levels. Point-of-care hemoglobin testing is being increasingly used to provide rapid results in many clinical settings, including the perioperative setting, where it enables rapid decision-making for administering red blood cell transfusions.
Although most point-of-care devices require invasive blood sampling, there are now noninvasive hemoglobin testing systems that offer the advantages of painless measurement and avoidance of exposure to blood-borne infections.
Invasive Tests for Hemoglobin Concentration
- HemoCue, Inc. (Cypress, CA) says that its HemoCue® Hemoglobin systems provide quick, simple, and reliable quantitative lab-quality hemoglobin results. There are a few options available. They all use precalibrated, portable, dual-wavelength analyzers that correct for lipemia, leucocytosis, and other sources of turbidity. A disposable microcuvette collects the exact amount of capillary, venous, or arterial blood, and automatically mixes the sample with reagents. The microcuvette is placed into the analyzer and results are displayed in about 1 min. The HemoCue Hb 201+ System is the second-generation, improved standard product. It is also available with data management capabilities (HemoCue Hv 201 DM System). Hemoglobin measurement by these two systems is based on a modified azidomethemoglobin method and photometry. The HemoCue Hb 301 System is optimized for use in primary care and blood donation settings, with results available in about 10 sec. The determination of hemoglobin concentration in this system is based on measuring the absorbance of whole blood at an oxyhemoglobin-deoxyhemoglobin isobestic point.
- Stanbio Laboratory (Boerne, Texas) produces the STAT-Site® MHgb, a palm-sized, battery-operated, dedicated hemoglobin analyzer. Measurement uses a single drop of fingerstick blood, and is based on the azidemethemoglobin method and reflectance photometry. The system consists of a reflectance meter and proprietary hemoglobin test cards that measure hemoglobin in seconds. Each package of reagent test cards includes a lot-specific quality CODE key for automatic calibration. The system automatically prechecks the test card when it is inserted into the meter. As soon as the drop of blood is added to the card, the sample is detected and the Hgb result is displayed on the LCD screen in either g/dL or mmol/L. The STAT-Site MHgb specifications include a linear range of 6–21 g/dL, within-run precision coefficient of variation (CV) ranging from 3.5% to 4.9%, and total precision CV from 2.9% to 4.2%.
Noninvasive Tests for Hemoglobin Concentration
- Masimo Corporation (Irvine, CA) manufactures the FDA-approved rainbow® signal extraction technology (SET) platform, based on rainbow pulse CO-oximetry, a technology that allows noninvasive, continuous measurement of multiple blood components, including total hemoglobin, as well as other physiological parameters. The platform consists of oximeters with a range of capabilities. Oximeters with fewer capabilities are upgradeable to complete functionality, that is, clinicians can choose the measurement capability they need at the time of purchase and add measurements at a later time. The oximeters are attached to the sensor by a cable, and the sensor is placed on the finger. Noninvasive sensor technology uses more than seven wavelengths of light to acquire data from the blood. Signal processing algorithms and adaptive filters together isolate, identify, and quantify various hemoglobin species. Results are then displayed numerically.
The Radical-7® monitor provides continuous monitoring of nine parameters, including total hemoglobin. It can be used for multiple sites and applications, including the operating room, postanesthesia care unit, intensive care unit, emergency care, and newborn screening.
The Pronto® provides spot-checking of total hemoglobin, in addition to three other parameters. Sensors of varying sizes and for various monitors are sold separately. Masimo claims that the accuracy of the Pronto for total hemoglobin, compared with invasive hemoglobin measurements from a laboratory CO-oximeter, showed: 1) 0.08 g/dL bias, 2) 0.96 g/dL at one standard deviation, and 3) for samples with respective hemoglobin concentrations.
- OrSense Ltd. (Petah-Tikva, Israel) manufactures the CE-marked, FDA-approved NBM 200, a noninvasive hemoglobin monitor using SpectOLight™ Occlusion Spectroscopy technology. The device operates by means of a ring-shaped sensor that fits on the finger and temporarily occludes blood flow, creating new blood dynamics which generate a unique, strong optical signal, yielding a high signal-to-noise and wholly blood-specific ratio. The sensor is connected to the portable desktop monitor, which features a backlit liquid crystal display and provides blood hemoglobin and pulse rate results in less than 90 sec. There are automatic self-tests and calibration checks at start-up and throughout performance. The monitor can operate on batteries or can be connected to the main electrical supply. There is a datalogger for 100 preceding measurements. The device has wide applicability, from point-of-care sites to blood banks and hospitals.
Please check out our Point of Care Devices (POC Diagnostic Devices) section to find manufacturers that sell these products