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	04/10/2026
Type of Reportable Event	Malfunction
Event or Problem Description
We received an allegation of questionable sodium electrode results for an unspecified number of patients' samples tested on a cobas 4000 c311 stand alone system.The clinicians questioned the initial results from the analyzer, prompting the rerun of the samples at a different laboratory using a different c311 system.The customer alleged that the repeat results were approximately 7 mmol/l lower and were more aligned with the expected results.Discrepancy results for 1 patient sample were provided: initial result: 148 mmol/l.Repeat result: 141 mmol/l.
Additional Manufacturer Narrative
The sodium electrode lot number and expiration date were not provided.The customer had calibration and qc failures.The investigation is ongoing.
Additional Manufacturer Narrative
The customer performed extensive troubleshooting.The actions taken include: replacing all consumables, the tubing, and the electrode twice.Conducting an air purge.Manually putting the activator through.Checking the drain port for crystals.The calibration consistently failed with the ise.E flag, and the qc results were randomly out of range.The replacement of the sodium electrode by the customer was reasonable.Despite reminders, no information was provided to carry out further investigation.The investigation did not identify a product problem.The cause of the event could not be determined.

• 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: 25067052
• Report Number: 1823260-2026-01718
• Device Sequence Number: 16139311
• Product Code: JJE
• UDI-Device Identifier: 04015630925551
• UDI-Public: 04015630925551
• Combination Product (Y/N): N
• Initial Reporter Country: UK
• 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): 06/05/2026

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): Initial
• Initial Date Received by Manufacturer: 04/10/2026
• Supplement Date Received by Manufacturer: 05/13/2026
• Initial Report FDA Received Date: 05/04/2026
• Supplement Report FDA Received Date: 06/05/2026
• 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
• Patient Sex: Unknown