MAUDE Adverse Event Report: ROCHE DIAGNOSTICS COBAS 4000 C311 STAND ALONE SYSTEM; CLINICAL CHEMISTRY ANALYZER

Catalog Number	04826876001
Medical Device Problem Code	Non Reproducible Results (4029)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	01/08/2026
Type of Reportable Event	Malfunction
Event or Problem Description
We received an allegation of questionable sodium electrode results for multiple patient samples tested on a cobas 4000 c311 stand alone system.One example of discrepant results for one patient sample was provided: on (b)(6) 2026, the initial result was 174 mmol/l.The initial result was not reported because it was elevated and did not match the expected values, prompting a rerun.On (b)(6) 2026, the repeat result: 142 mmol/l.The repeat result was deemed correct, as it was within the normal values and was reported outside the laboratory.
Additional Manufacturer Narrative
The sodium electrode lot number and expiration date were not provided.The calibration and qc were acceptable.The field service engineer (fse) checked the ion-selective electrode (ise) sipper pipette and observed white deposits on the upper surface of the cuvettes.He also reviewed the wash water and detergent volumes for the cuvettes and observed that the naoh solution volume was higher than the wash water volume.The fse cleaned the white deposits and adjusted the naoh solution volume.He then verified the correct dispensing from the other nozzles in the washing station and performed an ise calibration with successful results.The investigation is ongoing.
Additional Manufacturer Narrative
The reagent was purged, and the ise calibration was successful.The customer was using expired electrodes.The product labeling states: "on-board stability after installation the electrode is stable for the following time period: 2 months or 9000 tests, whichever comes first.The electrodes should be replaced after this time period has expired." the investigation did not identify a product problem.The cause of the event was due to an off-label use, where the customer was using expired electrodes.

• Brand Name: COBAS 4000 C311 STAND ALONE SYSTEM
• Common Device Name: CLINICAL CHEMISTRY ANALYZER
• Manufacturer (Section D): ROCHE DIAGNOSTICS; 9115 hague road; indianapolis IN 46250 0457
• Manufacturer (Section G): HITACHI HIGH TECH CORP.; 882 ichige hitachinaka; ibaraki 312-8 504; JA 312-8504
• Manufacturer Contact: natalie catton ; 9115 hague road; indianapolis, IN 46250
• MDR Report Key: 24233387
• Report Number: 1823260-2026-00341
• Device Sequence Number: 15999425
• Product Code: JJE
• UDI-Device Identifier: 04015630925551
• UDI-Public: 04015630925551
• Combination Product (Y/N): N
• Initial Reporter Country: AR
• PMA/510(K) Number: K060373
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Foreign,Health Professional,User Facility
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 03/06/2026

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 Catalogue Number: 04826876001
• 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: 01/12/2026
• Supplement Date Received by Manufacturer: 02/10/2026
• Initial Report FDA Received Date: 02/02/2026
• Supplement Report FDA Received Date: 03/06/2026
• 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: AZATHIOPRINE
• Patient Age: 20 YR
• Patient Sex: Male