The cartridges that are typically stocked for use by CCATT are the CHEM8+, CG8+, EG7+, and CG4+. Cartridges are each loaded with a sample of the patient’s blood and inserted into the bottom port of the analyzer for analysis.

The CG8+ cartridge (Figure 2) measures glucose, sodium, potassium, ionized calcium, hemoglobin, and hematocrit. The blue arrow just to the right of “CG8+” defines the fill mark when blood is loaded into the cartridge; this indicates the volume of blood necessary to perform the test.

The EG7 cartridge measures sodium, potassium, ionized calcium, hemoglobin, hematocrit, pH, PaCO2, PaO2, TCO2, HCO3, base excess, SO2.

The CHEM8+ cartridge (Figure 3) measures creatinine, Blood Urea Nitrogen (BUN), glucose, ionized calcium, anion gap, TCO2, chloride, potassium, and sodium. The fill mark is at the beginning of the blue segment.

The CG4+ cartridge measures lactate, pH, PaCO2, PaO2, TCO2, HCO3, base excess, SO2.

The quality controls for the i-STAT system are simulators and controls. There are two types of simulators for the i-STAT: internal and external. Internal simulators are built into the analyzer and external simulators (Figure 4) must be inserted into the analyzer in the same port that receives the cartridge. Both types of simulators mimic the signals that a cartridge, loaded with blood, would send to the analyzer; simulators validate the analyzer. Controls are liquids that are injected into the cartridge (instead of blood); the cartridge is then inserted into the analyzer and run to validate the cartridge. CCATT members are tasked to perform these quality checks to ensure lab tests are accurate.