SODIUM ELECTRODE

Description of Event or Problem

WE RECEIVED AN ALLEGATION OF QUESTIONABLE ISE RESULTS FOR 2 PATIENTS' SERUM SAMPLES TESTED ON A COBAS INTEGRA 400 PLUS ANALYZER. RESULTS FOR THE SODIUM (NA) TEST WERE AFFECTED. SAMPLE 1 (PATIENT 1): INITIAL RESULT: 129.2 MMOL/L. REPEAT RESULT: 136.9 MMOL/L. SAMPLE 2 (PATIENT 2): INITIAL RESULT: 134.3 MMOL/L. REPEAT RESULT: 143.3 MMOL/L. NO QUESTIONABLE RESULTS WERE REPORTED OUTSIDE THE LABORATORY AS THE CUSTOMER NOTICED THAT THE NA RESULTS WERE RUNNING LOW. THE SAMPLES WERE THEN REPEATED AND THE REPEAT RESULTS WERE DEEMED TO BE CORRECT.

Additional Manufacturer Narrative

THE NA ELECTRODE EXPIRATION DATE WAS NOT PROVIDED. THE COBAS INTEGRA 400 PLUS SERIAL NUMBER WAS (B)(6). THE NA ELECTRODE WAS INSTALLED ON (B)(6) 2024. THE CUSTOMER STATED THAT QC WENT OUT OF RANGE 4 TIMES BEFORE GETTING IT BACK WITHIN RANGE PRIOR TO THE EVENT. THE FIELD SERVICE ENGINEER FOUND THAT ONE PROBE FAILED. HE REPLACED THE NA ELECTRODE AND THE PROBE. PRECISION STUDIES WERE PERFORMED AND THEY WERE WITHIN SPECIFICATIONS. QC WAS PERFORMED AND IT WAS ACCEPTABLE. THE INVESTIGATION IS ONGOING.

Additional Manufacturer Narrative

THE CALIBRATION WAS LAST PERFORMED ON (B)(6) 2024 AND WAS ACCEPTABLE. QC RECOVERY WAS WITHIN RANGES. NO INDICATION OF A REAGENT'S PERFORMANCE ISSUE. THE FIELD SERVICE ENGINEER FOUND THAT THE ELECTRODE'S SHELF LIFE WAS EXCEEDED. THE SERVICE ACTIONS (REPLACING THE NA ELECTRODE AND THE PROBE) RESOLVED THE ISSUE. NO FURTHER ISSUES WERE REPORTED AFTER THE SERVICE VISIT.