Hyperglycemia Emergency Classification and Management

Diagnostic Criteria

The American Diabetes Association defines diabetic ketoacidosis (DKA) by the following laboratory criteria: plasma glucose ≥250 mg/dL, arterial pH <7.30, serum bicarbonate <15 mEq/L, and positive urine or serum ketones 1, 2
The American Diabetes Association defines hyperosmolar hyperglycemic state (HHS) by the following criteria: plasma glucose ≥600 mg/dL, arterial pH >7.30, serum bicarbonate ≥15 mEq/L, effective serum osmolality ≥320 mOsm/kg, small or absent ketones, and altered mental status or severe dehydration 1, 2, 3

Patients with blood glucose ≥250 mg/dL and symptoms of DKA or HHS, or glucose ≥600 mg/dL regardless of symptoms, require immediate medical intervention 4, 5
The American College of Clinical Endocrinologists recommends immediate medical attention for scenarios including blood glucose ≥180 mg/dL with vomiting, dehydration, or altered mental status, blood glucose ≥250 mg/dL persistently over 2 consecutive days, and any glucose reading >600 mg/dL 5

The American Diabetes Association notes that patients on SGLT2 inhibitors can develop DKA with glucose <200 mg/dL, and risk factors include very-low-carbohydrate diets, prolonged fasting, dehydration, and excessive alcohol intake 3, 5
The American College of Obstetricians and Gynecologists states that up to 2% of pregnancies with pregestational diabetes are complicated by DKA, and pregnant individuals may present with euglycemic DKA 3

The American Association of Clinical Endocrinologists recommends that home management of hyperglycemia is only appropriate when patients are hemodynamically stable, cognitively intact, able to tolerate oral hydration, and can administer subcutaneous insulin 5, 6
The American Diabetes Association advises that patients should seek immediate medical attention if they are unable to tolerate oral hydration, blood glucose levels do not improve with insulin administration, altered mental status develops, or any signs of worsening illness occur 3, 5

HHS typically evolves over several days to weeks, whereas DKA in type 1 or type 2 diabetes tends to develop much more rapidly, with dehydration severity and mental status changes being key distinguishing features 7
Profound dehydration with poor skin turgor and hypotension indicates crisis, and Kussmaul respirations suggest DKA with metabolic acidosis 7, 8
Patients can be normothermic or hypothermic despite infection, with hypothermia being a poor prognostic sign in crisis 8

Initial testing should include plasma glucose 9, serum electrolytes with calculated anion gap 8, serum ketones 7, blood urea nitrogen/creatinine 8, urinalysis with urine ketones 8, and complete blood count with differential 8
DKA must be distinguished from other causes of high-anion gap metabolic acidosis, including lactic acidosis and ingestion of certain drugs 8

Approximately 10% of DKA cases present with euglycemic DKA, requiring either hyperglycemia or prior diabetes history for diagnosis, and can occur with SGLT2 inhibitor use, reduced food intake, pregnancy, or alcohol use 10
Approximately 10% of patients present with concurrent DKA and HHS features, which is not expected in gastroenteritis with simple hyperglycemia 10

Caution is essential with patients complaining of abdominal pain, as symptoms could be either a result or a cause of DKA, and further evaluation is necessary if abdominal complaints do not resolve with treatment of the metabolic derangement 8
Infection, including gastroenteritis, commonly precipitates both DKA and HHS, and assessing precipitating factors is crucial 7, 8