MAUDE Adverse Event Report: ROCHE DIAGNOSTICS POTASSIUM ELECTRODE; ELECTRODE, ION SPECIFIC, POTASSIUM

Catalog Number	03111628180
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	03/26/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The cobas b221 6 roche omni s6 system serial number was (b)(6).The investigation is ongoing.
Event or Problem Description
We received an allegation about discrepant results for 2 patients' samples tested for potassium (k) on a cobas b221 6 roche omni s6 system.Patient 1 and patient 2 were initially tested (tube 1) with an arterial blood gas (abg) test on a cobas b221, while simultaneously, venous blood samples (tube 2) were drawn from patient 1 and patient 2 and tested on different analyzers.Patient 1: tube 1 result: 2.61 mmol/l.Tube 2 result: 4.2 mmol/l (tested on a beckman coulter au5800 instrument).Patient 2 was tested on (b)(6) 2025: tube 1 result: 3.74 mmol/l.Tube 2 result: 4.7 mmol/l (tested on a c503 analyzer).
Additional Manufacturer Narrative
Section b7 was updated.The customer alleged discrepant results for 2 additional patients' samples tested for potassium (k) on a cobas b221 6 roche omni s6 system.Patient 3 was tested on (b)(6) 2025: initial result: 5.23 mmol/l.Repeat result: 7.01 mmol/l (tested on c503).There was no sign of the sample that was tested on c503 being hemolyzed.Patient 4 was tested on (b)(6) 2025: initial result: 3.14 mmol/l.Repeat result: 5.49 mmol/l (tested on c503).The investigation is ongoing.
Additional Manufacturer Narrative
Medwatch field d4 was updated.The potassium electrode expiration date was not provided.The qc was noted to be acceptable.Based on the investigation of the data provided, the cobas b221 6 roche omni s6 system worked as designed.No irregularities of the calibration or sample signals were found, and no indication of an instrument malfunction was detected.The investigation did not identify a product problem.The cause of the event could not be determined.

• Brand Name: POTASSIUM ELECTRODE
• Common Device Name: ELECTRODE, ION SPECIFIC, POTASSIUM
• 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 46250-0457
• MDR Report Key: 22206167
• Report Number: 1823260-2025-01838
• Device Sequence Number: 15364731
• Product Code: CEM
• UDI-Device Identifier: 04015630014293
• UDI-Public: 04015630014293
• Combination Product (Y/N): N
• Initial Reporter Country: VM
• 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): 11/26/2025

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 Expiration Date: 04/25/2025
• Device Catalogue Number: 03111628180
• Device Lot Number: 31244347
• 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: 05/20/2025
• Supplement Date Received by Manufacturer: 08/12/2025; 11/03/2025
• Initial Report FDA Received Date: 06/13/2025
• Supplement Report FDA Received Date: 09/08/2025; 11/26/2025
• 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: Female