Postoperative Hypoglycemia after General Anesthesia in a Patient with Type I Diabetes Mellitus Wearing a Sensor-Augmented Pump

The present treatment options for type I diabetes mellitus, besides precise blood sugar (BS) management with a continuous glucose monitoring (CGM) system that continuously measures BS, include multiple daily injections (MDI) and continuous subcutaneous insulin infusion (CSII). The latest development is a sensor-augmented pump (SAP) consisting of CSII-incorporated CGM. Here, we present a case with type I diabetes mellitus and an SAP who experienced recurrent postoperative hypoglycemia. The patient was a 73-year-old woman in whom a sequestrectomy and antral lavage were planned because of implant pericoronitis of the maxillary right premolar. She had been diagnosed as having type I diabetes mellitus at the age of 53 years and had received an SAP implant at the age of 70 years; no diabetes mellitus-related complications had been reported. Her preoperative BS and hemoglobin A1c (HbA1c) levels were 95 mg/dl and 8.2%, respectively. On the day of the operation, her BS was 185 mg/dl; the SAP was stopped, and an intravenous drip for maintenance transfusion (4.3% glucose components) containing 4U of rapid-acting insulin (NovolinR) was started. Furthermore, general anesthesia was completed without a problem, and we restarted the SAP postoperatively. As she reported recurrent postoperative hypoglycemia, we administered a 20% glucose solution and maintenance transfusion intravenously. Her BS stabilized after changing to oral feeding. In this case, because the patient had type I diabetes mellitus and her BS management was expected to be challenging, we decided to stop the SAP during surgery only. Stopping oral ingestion and initiating tube feeding might have caused the postoperative hypoglycemia. Hence, using CGM and with the patient's consent, we intravenously administered a 20% glucose solution and maintenance transfusion, thereby preventing severe hypoglycemia.