Level 1, 2, and 3 controls for blood gas/electrolyte/metabolite cartridges are formulated at three clinically relevant levels with known pH and with known concentrations of sodium, potassium, chloride, ionized calcium, PCO2, PO2, TCO2, glucose, lactate, BUN/urea, and creatinine. Level 1 and 3 controls are typical stocked for deployed CCATTs.

Verifying hematocrit measurements, however, requires another type of control: the RNA Medical® Hematocrit Calibration Verification Controls. Levels 1, 3, and 5 should be run on the following cartridges: E3+, EC4+, 6+, EC8+, EG6+, EG7+, CG8+, and CHEM8+. This control is NOT typically stocked for CCATTs downrange.

Liquid controls used in a cartridge that measures oxygen concentration must stand at room temperature for a minimum of 4 hours before use; controls for other analytes only need to equilibrate at room temperature for 30 minutes. The analyzer should also stand at room temperature for 30 minutes.

Procedure for running a control:

Step 1: Put on gloves.

Step 2: Press the On button.

Step 3: Press the Menu key; then press 3 to select Quality Tests.

Step 4: Press 1 to select Control.

Step 5: You will be prompted to scan or manually enter the Operator ID and Control Number. It may be convenient to enter 1 as the operator ID for a level 1 control and 3 for a level 3 control; this may make it easier when comparing the results to the Value Assignment Sheet

Step 6: Press Scan to scan the barcode cartridge lot number.

Step 7: Remove the cartridge from the package, taking care to handle it only along the edges, otherwise the results may be affected. Place the cartridge on a flat surface.

Step 8: Shake the control ampule (Figure C1) hard 15–20 times (for at least 10 seconds) and then tap the ampule to restore the liquid to the bottom of the ampule.

Step 9: Open the ampule by snapping off the tip. Protect fingers with gauze or use an ampule breaker.

Step 10: Immediately transfer control to syringe as follows: use a clean 3 mL syringe. Replace attached needle with a 19-gauge blunt tip needle, if available, for safety. Avoid drawing air bubbles into the syringe.

Step 11: Immediately expel 3 drops of control on a pad/gauze and then fill cartridge to the fill line and seal the cartridge (see Appendix A for details). Aqueous-based solutions such as controls do not have the buffering capabilities of whole blood; therefore, once opened, they must be immediately transferred to the cartridge (unlike with a patient’s sample).

Step 12: Do not use the solution left in a syringe or ampule for additional testing of cartridges that contain sensors for ionized calcium, pH, PCO2, or PO2; a new ampule must be used.

Step 13: Insert cartridge into the analyzer; do not remove until Do Not Remove Cartridge – Cartridge Locked message is gone.

Step 14: Control Evaluation. Compare the results to the Value Assignment Sheet. If any result is out of range, repeat the control testing with a fresh ampule and syringe. If any result is still out or range, do not use any of the cartridges from this lot. Value Assignment Sheets are obtained from the Abbott Point of Care website (http://www.abbottpointofcare.com/Customer-Info- Center/Value-Assignment-Sheets.aspx). You will need to know the CLEW version on your device and the lot number of the control solution you used.

Note: Correction of PO2 value is required when running controls at locations more than 1000 feet above sea level. Use the barometric pressure reading from the i-STAT status screen and the following formulas:

  • For PO2 values < 150 mmHg: for every decrease of 15 mmHg in barometric pressure from 760 mmHg, add 1 mmHg to observed PO2  value. 
  • For PO2 values > 150 mmHg for every decrease of 35 mmHg in barometric pressure from 760 mmHg, add 1 mmHg to observed POvalue.