This study is assessing the accuracy of continuous glucose monitors during surgical procedures requiring anesthesia.

This study is an observational study design that includes collection of continuous glucose data and venous blood glucose data (from either an IV or fingerstick) from a blood glucose meter. All subjects will be undergoing a surgical procedure that requires anesthesia. The primary outcome of this study is to evaluate the accuracy of the CGM glucose values in comparison to the reference glucometer glucose value during anesthesia. There is currently limited data on accuracy of CGMs during these events and therefore it is not know whether CGM glucose data is reliable to be used as the sole source of glucose monitoring during surgery.

Inclusion Criteria:

1. Participants will be 2 to 26 years of age at the time of enrollment.
2. Participants will have a diagnosis of type 1 diabetes on insulin therapy and requiring close glucose monitoring during the hospitalization and the perioperative period.
3. Participant currently wearing a continuous glucose monitor (for example: Dexcom G6 or G7; Freestyle Libre 2, 2 Plus, or 3; Medtronic Guardian 3 or 4; or future sensors as they become available) for home diabetes management and willing to share personal CGM data with the BDC clinical CGM account.

Exclusion Criteria:

1. Pregnancy.
2. Currently using hydroxyurea.
3. A condition that the investigator determines would prevent the patient from participation.

All participants will have a clinical diagnosis of type 1 diabetes and be wearing a continuous glucose monitor as part of routine care.