Euglycemic Diabetic Ketoacidosis-Like State During the Treatment of Diabetic Ketoacidosis in Fulminant Type 1 Diabetes: A Case Report.

Diabetic ketoacidosis (DKA) is a life-threatening acute metabolic complication of diabetes characterized by hyperglycemia, metabolic acidosis, and ketosis. Appropriate insulin therapy and glucose supplementation during treatment are essential to prevent persistent ketoacidosis. A 53-year-old man presented with a one-week history of polyuria. Urinalysis revealed 3+ ketonuria and 3+ glucosuria. Laboratory tests showed a hemoglobin A1c (HbA1c) level of 8.0%, plasma glucose at 720 mg/dL, arterial pH of 7.23, and bicarbonate (HCO₃⁻) at 15.9 mEq/L. He was diagnosed with DKA and was immediately admitted for treatment with intravenous saline and continuous regular insulin infusion. Eight hours after the initiation of therapy, plasma glucose decreased to 169 mg/dL; however, saline infusion without glucose supplementation was continued. After 30 hours, he was transferred to the diabetes department while still receiving saline and a minimal insulin infusion rate (0.1 U/h). At that time, despite a plasma glucose level of 125 mg/dL, metabolic acidosis persisted (pH 7.28) with continued 3+ ketonuria, consistent with persistent ketoacidosis despite euglycemia during treatment of DKA. The treatment regimen was revised to include glucose-containing intravenous fluids and an appropriate insulin dose. Following this adjustment, metabolic acidosis resolved. Further evaluation revealed serum C-peptide at <0.03 ng/mL and anti-glutamic acid decarboxylase (GAD) antibody at <5.0 U/mL, leading to a diagnosis of fulminant type 1 diabetes. This case highlights that insufficient glucose supplementation and inadequate insulin administration during DKA management may result in persistent ketoacidosis despite normalization of plasma glucose levels.