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

Catalog Number	04826876001
Medical Device Problem Codes	Decrease in Suction (1146); Obstruction of Flow (2423); Low Test Results (2458); No Flow (2991); Suction Failure (4039)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	12/15/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The reagent electrode information was not provided.The field service engineer (fse) performed adjustments and checked the gear pump pressure, cuvette fill levels, washing station, and suction.The investigation is ongoing.
Event or Problem Description
There was an allegation of questionable sodium (na) and potassium (k) results for 3 patient samples on a cobas 4000 c311 stand alone system.The customer was prompted to repeat the patient samples because the clinical staff questioned the results as they did not match the blood gas results.For sample 1, the initial na result was 128 mmol/l and the initial k result was 3.72 mmol/l.The repeat na result was 141 mmol/l and the repeat k result was 4.04 mmol/l.For sample 2, the initial na result was 130 mmol/l and the initial k result was 3.52 mmol/l.The repeat na result was 142 mmol/l and the repeat k result was 3.82 mmol/l.For sample 3, the initial na result was 132 mmol/l and the initial k result was 3.82 mmol/l.The repeat na result was 145 mmol/l and the repeat k result was 4.15 mmol/l.
Additional Manufacturer Narrative
The customer stated that they received multiple calibration errors.The root cause of the event was found to be consistent with compromised calibration standards, possibly due to being left out too long.No product problem was identified.
Additional Manufacturer Narrative
The electrodes were recalibrated, which resolved the issue.The investigation determined that operator error caused the event (calibration standard handling error).The investigation did not identify a product problem.

• 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: 23979526
• Report Number: 1823260-2026-00065
• Device Sequence Number: 4630074
• Product Code: JJE
• UDI-Device Identifier: 04015630925551
• UDI-Public: 04015630925551
• Combination Product (Y/N): N
• Initial Reporter Country: GM
• 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,Followup
• Report Date (Section B): 03/11/2026

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: 12/15/2025
• Supplement Date Received by Manufacturer: 01/07/2026; 02/16/2026
• Initial Report FDA Received Date: 01/06/2026
• Supplement Report FDA Received Date: 01/28/2026; 03/11/2026
• 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