What classifies as a hyperglycemia emergency?

What Classifies as a Hyperglycemia Emergency

A hyperglycemia emergency exists when blood glucose ≥250 mg/dL with symptoms of diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), or when glucose ≥600 mg/dL regardless of symptoms, requiring immediate medical intervention. 1, 2

Diagnostic Criteria for Hyperglycemic Emergencies

Diabetic Ketoacidosis (DKA)

DKA is defined by the following laboratory criteria 3:

• Plasma glucose ≥250 mg/dL
• Arterial pH <7.30 (or venous pH <7.27)
• Serum bicarbonate <15 mEq/L
• Positive urine or serum ketones (or blood β-hydroxybutyrate >2 mmol/L) 1
• Anion gap ≥10 mEq/L 3

The severity stratification matters for management 3:

• Mild DKA: pH 7.25-7.30, bicarbonate 15-18 mEq/L, alert mental status
• Moderate DKA: pH 7.00-7.24, bicarbonate 10-15 mEq/L, alert to drowsy
• Severe DKA: pH <7.00, bicarbonate <10 mEq/L, stupor or coma

Hyperosmolar Hyperglycemic State (HHS)

HHS is characterized by 3:

• Plasma glucose ≥600 mg/dL
• Arterial pH >7.30
• Serum bicarbonate ≥15 mEq/L
• Effective serum osmolality ≥320 mOsm/kg (calculated as: 2[Na] + glucose/18)
• Small or absent ketones
• Altered mental status or severe dehydration 3, 1

Important caveat: Approximately one-third of hyperglycemic emergencies present with a hybrid DKA-HHS picture, showing features of both conditions 3.

Clinical Presentation Requiring Emergency Intervention

Immediate Emergency Department Presentation Required

The following scenarios mandate immediate medical attention 2:

• Blood glucose ≥180 mg/dL with vomiting, dehydration, or altered mental status
• Blood glucose ≥250 mg/dL persistently over 2 consecutive days (even without symptoms)
• Any glucose reading >600 mg/dL or exceeding home glucometer capacity
• Blood glucose >200 mg/dL with ketones present 1, 2

Classic Symptoms of Hyperglycemic Crisis

DKA typically develops over hours to days and presents with 3:

• Polyuria, polydipsia, weight loss
• Nausea, vomiting, abdominal pain (in DKA specifically)
• Kussmaul respirations (deep, rapid breathing)
• Fruity breath odor 4
• Dehydration with poor skin turgor
• Tachycardia and hypotension
• Mental status changes ranging from alertness to coma

HHS develops more gradually over days to a week and commonly presents with 3:

• Profound dehydration
• Altered mental status is common (unlike DKA where patients are usually alert)
• Often copresenting with acute illness (infection, stroke, myocardial infarction)
• Absence of Kussmaul respirations and fruity breath

Critical pitfall: Hypothermia, if present, is a poor prognostic sign despite infection being a common precipitating factor 3. Do not dismiss the possibility of infection based on normal or low temperature.

Special Populations and Atypical Presentations

Euglycemic DKA

**Patients on SGLT2 inhibitors can develop DKA with glucose <200 mg/dL** 3, 2. Risk factors include very-low-carbohydrate diets, prolonged fasting, dehydration, and excessive alcohol intake 3. Any SGLT2 inhibitor user with glucose >200 mg/dL and ketones present warrants immediate evaluation 2.

Pregnancy

Up to 2% of pregnancies with pregestational diabetes are complicated by DKA 3. Pregnant individuals may present with euglycemic DKA (glucose <200 mg/dL), and diagnosis may be hindered by mixed acid-base disturbances, particularly with hyperemesis 3. Due to significant feto-maternal harm risk, pregnant patients at risk for DKA should seek immediate medical attention with any concern 3, 2.

Pediatric Patients

In children and adolescents, the same diagnostic criteria apply, but initial insulin bolus is not recommended—start with continuous insulin infusion at 0.1 unit/kg/h 3. The transition period from adolescence to adulthood is particularly critical for preventing repetitive admissions 5.

When Home Management May Be Attempted

Home management is only appropriate when all of the following conditions are met 2:

• Glucose >200 mg/dL with mild symptoms
• Hemodynamically stable
• Cognitively intact
• Able to tolerate oral hydration
• Can administer subcutaneous insulin
• Can perform frequent blood glucose and ketone monitoring
• Has access to diabetes care team support

However, patients should seek immediate medical attention if 3:

• Unable to tolerate oral hydration
• Blood glucose levels do not improve with insulin administration
• Altered mental status develops
• Any signs of worsening illness occur

Institutional and Correctional Settings

Facilities should implement policies requiring physician notification for 3, 2:

• Blood glucose <50 mg/dL or >350 mg/dL
• Systems to identify patients with consistently elevated glucose and intercurrent illness

Security staff supervising high-risk patients should be trained to recognize symptoms of hyperglycemic crisis and ensure prompt medical attention, as severe hyperglycemia with altered mental status can be confused with intoxication or withdrawal 3, 2.

Critical Pitfalls to Avoid

• Do not dismiss glucose >200 mg/dL in symptomatic patients, even with chronic poor control, as this may represent acute decompensation 2
• Do not wait for classic DKA symptoms in pregnant patients, as presentation may be atypical 2
• Do not assume safety from DKA in SGLT2 inhibitor users if glucose is <250 mg/dL—euglycemic DKA can occur 2
• Do not confuse altered mental status from hyperglycemia with intoxication or withdrawal—immediately check blood glucose in any patient with diabetes exhibiting confusion, agitation, or diaphoresis 3, 2
• Do not delay fluid resuscitation in hypotensive patients with hyperglycemia 1, 6
• Do not underestimate severity even if the patient appears clinically stable 1, 6