MAUDE Adverse Event Report: ROCHE DIAGNOSTICS COBAS B 221 <6> SYSTEM; BLOOD GAS ANALYZER

Catalog Number	03337154001
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	11/14/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The potassium electrode lot number and expiration date were not provided.The investigation is ongoing.
Event or Problem Description
There was an allegation of a questionable potassium electrode result from the cobas b 221 <6> system, the unit of measurement was requested but not provided.Patient 1's initial result from the b221 system was 7, and the result from an unspecified chemistry analyzer was 3.5.Patient 2's initial result from the b221 system was 8, and the result from an unspecified chemistry analyzer was 3.3.Additional results were provided.It is unclear if these are additional patient results or qc results.Clarification has been requested but has not been provided.The initial result from the b221 system was 6.13, and the repeat result on another cobas b221 system was 3.27.
Additional Manufacturer Narrative
The unit of measurement for the potassium results is mmol/l.Exact results were provided for both patients.Additional questionable sodium electrode results from the cobas b 221 <6> system were provided for patient 1.Patient 1's initial potassium result was 13.27 mmol/l, and the repeat result with another analyzer was 6.13 mmol/l.The initial sodium result was 126.1 mmol/l, and the repeat result with another analyzer was 133.2mmol/l.Patient 1 had a potassium result from the previous day of the event of 6.6 mmol/l.Patient 2's initial result was 7.55 mmol/l, and the repeat result with another analyzer was 3.57 mmol/l.The samples were repeated because the customer noticed that they gave too high a result.The investigation is ongoing.
Additional Manufacturer Narrative
The qc was within range on the date of the event.A field service engineer (fse) was able to resolve the issue by replacing the potassium and chloride electrodes.The cause of the event could not be determined.

• Brand Name: COBAS B 221 <6> SYSTEM
• Common Device Name: BLOOD GAS ANALYZER
• Manufacturer (Section D): ROCHE DIAGNOSTICS; 9115 hague road; indianapolis IN 46250 0457
• Manufacturer (Section G): ROCHE DIAGNOSTICS GMBH; sandhofer strasse 116; mannheim (baden-wurttemberg) 68305 ; GM 68305
• Manufacturer Contact: natalie catton ; 9115 hague road; indianapolis, IN 46250
• MDR Report Key: 23778447
• Report Number: 1823260-2025-05061
• Device Sequence Number: 10075926
• Product Code: CEM
• UDI-Device Identifier: 04015630018345
• UDI-Public: 04015630018345
• Combination Product (Y/N): N
• Initial Reporter Country: AR
• PMA/510(K) Number: K032311
• 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): 05/08/2026

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: 03337154001
• 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: 11/14/2025
• Supplement Date Received by Manufacturer: 12/16/2025; 04/16/2026
• Initial Report FDA Received Date: 12/11/2025
• Supplement Report FDA Received Date: 01/06/2026; 05/08/2026
• 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