ELECTRONIC SIMULATORS
- The i-STAT analyzer has both an internal and external simulator to perform quality checks. Simulators mimic the signals that would be sent from a cartridge charged with blood to validate whether the analyzer is functioning properly.
- The analyzer runs a comprehensive check with the internal simulator each time a patient’s blood sample is tested.
- The external simulator needs to be plugged into the analyzer where a cartridge is attached. The external electronic simulator should be run when indicated by the i-STAT device or every 8 hours while in use. Additionally, it is recommended to run the external simulator prior to any mission and then again if the mission is over 8 hours. The testing procedure takes approximately 120 seconds. Appendix B details how to run an external simulator.
- Any analyzer that fails an electronic simulator check twice (internal or external) should be removed from service and turned in for maintenance.
- The i-STAT analyzer is programmed to lock out if the internal or external simulator does not pass the quality control.
LIQUID CONTROLS
- Liquid controls, which are injected into cartridges, verify the cartridges are producing accurate results and should be used each time a new batch of cartridges is opened. Controls may also be ran if there is concern that a group of cartridges was placed in an environment outside of the storage guidelines – for example, in a place with an ambient temperature above 30°C (86°F). In particular, Level 1, 2, and 3 controls for blood gas/electrolyte/metabolite cartridges are formulated solutions that represent 3 clinically relevant levels of known pH and with known concentrations of sodium, potassium, chloride, ionized calcium, PCO2, PO2, TCO2, glucose, lactate, BUN, and Level 1 and 3 controls are typically stocked for deployed CCATTs. Note: Hemoglobin is validated with another type of control (RNA Medical® Hematocrit Calibration Verification) that is not typically stocked for CCATTs.
- Liquid controls do not need to be run if cartridges are obtained from a military treatment facility (MTF) lab that complies with this Clinical Practice Guideline (CPG). One should not assume, however, that the MTF is running controls with their cartridges.
- Consult the manufacturer’s documentation if you plan to use cartridges not listed in this CPG because you will need to obtain the proper controls and run them prior to use, as well as update the software through your local Biomedical Equipment shop.
- Appendix C describes how to run controls.
INTERNAL QUALITY CHECK
If stars (***) are displayed instead of a lab result, it means that a test failed the internal quality checks. All other reported results are accurate as long as the sample integrity is not in question. If this occurs, one can remix the tube of blood and repeat the test using a new cartridge. If the result fails to display again, draw a fresh blood sample and repeat the test. If the result is still not displayed, consider turning the device in for maintenance or call technical support.