MAUDE Adverse Event Report: DEXCOM, INC. DEXCOM G7 CONTINUOUS GLUCOSE MONITORING SYSTEM

Catalog Number	STP-GT-002
Medical Device Problem Code	Incorrect, Inadequate or Imprecise Result or Readings (1535)
Health Effect - Clinical Codes	Headache (1880); Nausea (1970); Vomiting (2144); Diabetic Ketoacidosis (2364); Loss of consciousness (2418); Polydipsia (2604)
Date of Event	08/30/2025
Type of Reportable Event	Death
Event or Problem Description
It was reported that an inaccuracy between the continuous glucose monitor (cgm) and the blood glucose (bg) meter occurred.During the event the patient was using a dexcom g7 sensor in combination with a tandem t-slim pump in closed loop mode.The reporter (healthcare provider) stated that the day before the event, the patient was been experiencing signs of ketoacidosis.The patient did not seek medical help on that day.No cgm reading was reported from that day but it was stated that the patient did not take any fingerstick readings at that time and relied solely on the cgm reading.On the day of the event, the cgm reading was reading 2.0 mmol/l and the patient was unable to raise the level on her own.It was unknown by whom they were called, but an ambulance arrived to the patient´s location, and the patient was administered glucose (route unknown), which brought the ¿level¿ to 5.0 mmol/l.There is no information reported that a fingerstick was taken at that time, and the physician who reported the event stated that ¿the ambulance personal should have checked the capillary blood glucose in the ambulance¿.The patient was brought to the emergency department.It was stated that ¿before blood glucose could be checked, the patient was found unresponsive¿, and ¿had been alone for approximately 20 minutes¿.When the blood glucose level was tested, the patient had a blood glucose reading of 80.0 mmol/l and was in severe acidosis.Resuscitation was attempted for 45 minutes but was unsuccessful.According to the information received, the patient passed away 7 days after the day of the event.No data was provided for evaluation.The allegation and the probable cause could not be determined.There were no reported glucose values available to search within the parkes error grid calculator.Dexcom has reached out to tandem to request tandem's data investigation and cgm data.A follow up report will be submitted upon completion of the data investigation if received.No additional patient or event information is available.
Additional Manufacturer Narrative
(b)(4).Diabetes mellitus is a known cause of diabetic ketoacidosis.
Additional Manufacturer Narrative
(b)(4).B5: describe event or problem - additional.H2: additional information.H6: type of investigation - additional.H6: investigation findings.
Event or Problem Description
Subsequent to the initial mdr, no data was provided for investigation as dexcom is unable to retrieve the relevant patient data for review.The allegation and probable cause could not be determined.
Additional Manufacturer Narrative
(b)(4).B5 describe event or problem - correction to the following statement in the initial mdr, "the reporter (healthcare provider) stated that the day before the event, the patient has been experiencing signs of ketoacidosis." h2: additional information.H6: health effect - impact code - additional.H6: health effect - clinical code - additional.
Event or Problem Description
The reporter (healthcare provider) stated that the day before the event, the patient was been experiencing signs of ketoacidosis, severe thirst, nausea, vomiting, and a headache.

• Brand Name: DEXCOM G7 CONTINUOUS GLUCOSE MONITORING SYSTEM
• Common Device Name: CONTINUOUS GLUCOSE MONITOR
• Manufacturer (Section D): DEXCOM, INC.; 6340 sequence dr.; san diego CA 92121
• Manufacturer Contact: ashley spoto ; 6340 sequence dr.; san diego, CA 92121 ; 8582000200
• MDR Report Key: 23085390
• Report Number: 3004753838-2025-263103
• Device Sequence Number: 9248763
• Product Code: QBJ
• UDI-Device Identifier: 00386270004055
• UDI-Public: (01)00386270004055
• Combination Product (Y/N): N
• Initial Reporter Country: SE
• PMA/510(K) Number: K213919
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Foreign,Distributor
• Initial Reporter Occupation: Other
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 12/23/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Catalogue Number: STP-GT-002
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 09/10/2025
• Supplement Date Received by Manufacturer: 11/17/2025; Not provided
• Initial Report FDA Received Date: 09/18/2025
• Supplement Report FDA Received Date: 12/02/2025; 12/23/2025
• Was Device Evaluated by Manufacturer? (Y/N): No
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Concomitant Medical Products and Therapy/Usage Dates: INSULIN PUMP.
• Outcome Attributed to Adverse Event: Death; Other
• Patient Sex: Female