NA ELECTRODE

Additional Manufacturer Narrative

THE COBAS PRO ISE ANALYZER SERIAL NUMBER WAS (B)(6).

Description of Event or Problem

WE RECEIVED AN ALLEGATION OF DISCREPANT RESULTS FOR 2 PATIENT SAMPLES TESTED FOR NA ELECTRODE (NA) AND CL ELECTRODE (CL) ON A COBAS PRO ISE ANALYTICAL UNIT. THIS MEDWATCH WILL COVER NA. REFER TO MEDWATCH WITH A1 PATIENT IDENTIFIER (B)(6) FOR INFORMATION ON THE CL RESULTS. PATIENT 1 INITIAL NA RESULT WAS 173.1 MMOL/L. THE REPEAT RESULT WAS 158.2 MMOL/L. PATIENT 2 INITIAL NA RESULT WAS 160.7 MMOL/L. THE REPEAT RESULT WAS 142.1 MMOL/L. THE INITIAL CL RESULT WAS 119.3 MMOL/L. THE REPEAT RESULT WAS 107.5 MMOL/L. THE REPEAT RESULTS WERE PERFORMED ON A DIFFERENT ANALYZER AND WERE BELIEVED TO BE CORRECT.

Additional Manufacturer Narrative

CALIBRATION WAS LAST PERFORMED ON 08-DEC-2024 WITH ACCEPTABLE RESULTS. QC WAS ACCEPTABLE. AN "ABNORMAL ASPIRATION SAMPLE PIPETTER" ALARM WAS OBSERVED ON THE ALARM TRACE DATA. THE FIELD SERVICE ENGINEER (FSE) DID NOT IDENTIFY A CAUSE FOR THE EVENT. THE FSE CLEANED AND RESEATED THE DILUTION CUP, CLEANED THE VACUUM NOZZLE AND REPLACED THE SIPPER NOZZLE, PERFORMED ISE PRIMES AND AIR PURGES, DRIED MOISTURE OFF OF ELECTRODES, AND CLEANED ANY BUILDUP AROUND THE ACRYLIC BLOCKS. ISE CHECKS, CALIBRATION, QC, AND PRECISION RESULTS WERE ALL ACCEPTABLE. THE INVESTIGATION DID NOT IDENTIFY A PRODUCT PROBLEM. THE CAUSE OF THE EVENT COULD NOT BE DETERMINED.