Severe Hyperglycemic Crisis: A Presentation of Diabetic Ketoacidosis Requiring Intubation.

Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are serious metabolic disturbances that can occur in diabetes, and although they are often described separately, they can share features in clinical practice. This report describes the case of a 62-year-old male patient with type II diabetes mellitus and significant medication nonadherence who presented to the emergency department unresponsive with a Glasgow Coma Scale score of 3. Initial evaluation revealed profound hyperglycemia with a serum glucose level of 1,033 mg/dL, severe metabolic acidosis, an anion gap of 44, and positive ketones, consistent with a mixed DKA/HHS presentation. The patient required emergent intubation, aggressive intravenous fluid resuscitation, insulin therapy, and electrolyte correction. Despite extensive evaluation, no infectious source was identified, and medication nonadherence was determined to be the likely precipitating factor. This case underscores the clinical importance of recognizing overlapping features of DKA and HHS, as reliance on glucose thresholds alone may result in misclassification and delayed treatment. It reinforces the need for comprehensive metabolic assessment in severely hyperglycemic patients and supports viewing DKA and HHS as points along a continuum rather than isolated entities. Additionally, this case highlights the critical role of prevention through diabetes education, medication access, and adherence support to reduce recurrence and improve outcomes.