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

Catalog Number	04826876001
Medical Device Problem Code	Incorrect, Inadequate or Imprecise Result or Readings (1535)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	04/07/2026
Type of Reportable Event	Malfunction
Event or Problem Description
There was an allegation of questionable sodium electrode and bicarbonate assay results with several patient samples tested on the cobas 4000 c311 stand alone system.Sample 1: the initial sodium result was 150 mmol/l.The repeat sodum result was 136 mmol/l.Sample 2: the initial sodium result was 216 mmol/l.The repeat sodum result was 140 mmol/l.Sample 3: the initial bicarbonate result was 50 mmol/l.The repeat bicarbonate result was 23.2 mmol/l.The field service engineer (fse) cleaned the cuvettes, fixed a damaged vacuum tube, and performed qc and calibration successfully.However, additional questionable results were generated.Sample 4: the initial sodium result was 158 mmol/l.The repeat sodum result was 139 mmol/l.Sample 5: the initial sodium result was 128 mmol/l.The repeat sodum result was 139 mmol/l.Sample 6: the initial sodium result was 128 mmol/l.The repeat sodum result was 142 mmol/l.Sample 7: the initial sodium result was 123 mmol/l.The repeat sodum result was 141 mmol/l.
Additional Manufacturer Narrative
The electrode and reagent lot numbers were requested but were not provided.The investigation is ongoing.

• 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: 25047436
• Report Number: 1823260-2026-01703
• Device Sequence Number: 9781256
• 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): 06/10/2026

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: 04/08/2026
• Supplement Date Received by Manufacturer: 05/19/2026
• Initial Report FDA Received Date: 04/30/2026
• Supplement Report FDA Received Date: 06/10/2026
• 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