MAUDE Adverse Event Report: ROCHE DIAGNOSTICS COBAS C 111 ANALYZER WITH ISE; CLINICAL CHEMISTRY ANALYZER

Catalog Number	04777433001
Medical Device Problem Codes	Low Test Results (2458); Non Reproducible Results (4029)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	12/18/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Medwatch fields d1, d2a, d2b, d4, g1 and g4 were updated.The investigation is ongoing.
Additional Manufacturer Narrative
The cobas c 111 analyzer (with ise) serial number was(b)(6).The qc was low but still within the range.The customer stopped running the sodium test.The investigation is ongoing.
Event or Problem Description
We received an allegation of questionable ion-selective electrode (ise) sodium electrode results for 1 patient sample tested on a cobas c 111 analyzer with ise.Initial result: 129 mmol/l.The customer noticed that the initial result was lower than expected and sent the sample to a reference laboratory, where it was repeated on a cobas 8000 cobas ise module.No questionable result was reported outside the laboratory.1st repeat result: 130 mmol/l.2nd repeat result: 137 mmol/l.The repeat result of 130 mmol/l was deemed to be correct.
Additional Manufacturer Narrative
A field service engineer (fse) found that the ion-selective electrode (ise) electrode required replacement.He replaced the sodium electrode and the ise reference electrode.Ise calibration, instrument check, ise performance check, and qc were performed, and they were all within specifications.The instrument was performing within specifications.The service action of replacing the ise reference electrode resolved the issue.The root cause was due to an issue with the ise reference electrode.

• Brand Name: COBAS C 111 ANALYZER WITH ISE
• Common Device Name: CLINICAL CHEMISTRY ANALYZER
• Manufacturer (Section D): ROCHE DIAGNOSTICS; 9115 hague road; indianapolis IN 46250 0457
• Manufacturer (Section G): ROCHE INSTRUMENT CENTER AG TEGIMENTA; forrenstrasse; rotkreuz 6343 ; SZ 6343
• Manufacturer Contact: natalie catton ; 9115 hague road; indianapolis, IN 46250-0457
• MDR Report Key: 24040056
• Report Number: 1823260-2026-00151
• Device Sequence Number: 9075032
• Product Code: JJE
• UDI-Device Identifier: 04015630924769
• UDI-Public: 04015630924769
• Combination Product (Y/N): N
• Initial Reporter State: WI
• Initial Reporter Country: US
• PMA/510(K) Number: K071211
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 03/26/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 03/13/2026
• Device Catalogue Number: 04777433001
• Device Lot Number: 31253747
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 12/18/2025
• Supplement Date Received by Manufacturer: 01/18/2026; 03/04/2026
• Initial Report FDA Received Date: 01/12/2026
• Supplement Report FDA Received Date: 02/09/2026; 03/26/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Is the Device Labeled for Single Use? (Y/N): No
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: ALBUTEROL INHALER (EVERY 4 HOURS AS NEEDED); ZYLOPRIN (ALLOPURINOL) 300 MG DAILY
• Patient Age: 45 YR
• Patient Sex: Female