Hyperglycemic Crises: Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar State

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS) are the two most serious hyperglycemic emergencies in patients with diabetes mellitus. DKA most often occurs in patients with type 1 diabetes, but patients with type 2 diabetes are susceptible to DKA under stressful conditions such as trauma, surgery, or infections. HHS is more common in adult and elderly patients with poorly controlled type 2 diabetes. In the United States, the number of admissions for DKA has increased during the past decade to ∼165,000 cases of each year. The rate of hospitalization for HHS is significantly lower, accounting for <1% of all diabetes-related admissions. DKA and HHS are characterized by insulinopenia and severe hyperglycemia; clinically, these two conditions differ by severity of metabolic acidosis, dehydration, and ketonemia. The overall mortality recorded among adults is <1–2% in patients with DKA and ∼10–15% in patients with HHS. Management objectives for DKA and HHS include restoration of circulatory volume and tissue perfusion; correction of hyperglycemia, ketogenesis, and electrolyte imbalance; and identification and treatment of the precipitating event. This review describes the clinical presentation, precipitating causes, diagnosis, and acute management of these diabetic emergencies and of practical strategies for their prevention.