When to Seek Emergency Care for Hyperglycemia
Patients should seek emergency care when blood glucose levels exceed 180 mg/dL (10.0 mmol/L) with symptoms of severe hyperglycemia, or when levels are persistently above 250 mg/dL (13.9 mmol/L) over 2 consecutive days regardless of symptoms. 1
Glucose Thresholds Requiring Emergency Department Evaluation
- Blood glucose ≥180 mg/dL (10.0 mmol/L) with symptoms such as vomiting, dehydration, altered mental status, or severe illness requires immediate ED evaluation 1, 2
- Persistent glucose values >250 mg/dL (13.9 mmol/L) over 2 consecutive days, even without symptoms, warrant urgent medical attention 1
- Any glucose reading too high for a home glucometer to measure requires immediate medical evaluation 1
- Patients with symptoms of diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) should go to the ED regardless of specific glucose value 2
Risk Factors for Adverse Outcomes
- Lack of self-monitoring of blood glucose significantly increases risk of severe hyperglycemia requiring medical assistance 3
- Previous episodes of severe hyperglycemia are independent risk factors for future episodes requiring emergency care 3
- Elderly patients, those with psychological disorders (insomnia, dementia, depression), and those living in rural areas have higher risks of neurological sequelae from severe hyperglycemia 3
- Prolonged duration of untreated hyperglycemia increases risk of complications 3, 4
Hospital Management Thresholds
- For hospitalized patients, insulin therapy should be initiated when glucose levels are persistently ≥180 mg/dL (10.0 mmol/L) 1
- Once insulin therapy is started, the target glucose range should be 140-180 mg/dL (7.8-10.0 mmol/L) for most patients 1
- More stringent goals (110-140 mg/dL) may be appropriate for selected patients if achievable without significant hypoglycemia 1
Special Considerations
- Patients with type 1 diabetes should seek emergency care at lower thresholds, especially if ketones are present in urine or blood 2
- Patients who are sick, vomiting, unable to keep fluids down, or showing signs of dehydration should go to the ED even at lower glucose levels 1, 2
- Hyperglycemia in the ED is associated with increased mortality (odds ratio 1.92) and longer hospital stays, highlighting the importance of prompt treatment 5
- Patients with altered mental status and hyperglycemia require immediate evaluation as hypoglycemic encephalopathy can occur with prolonged glucose abnormalities 4
Common Pitfalls
- Focusing solely on glucose reduction in the ED without addressing underlying causes may lead to recurrent episodes 6, 7
- Discharge glucose levels alone may not predict short-term adverse outcomes, but persistent hyperglycemia should still be addressed 6
- Inadequate communication about hyperglycemia in ED referral letters can lead to suboptimal follow-up care 5
- Overaggressive glucose lowering (targeting <110 mg/dL) can increase risk of hypoglycemia and associated mortality 1
Remember that these recommendations are based on clinical guidelines and should be applied with consideration of individual patient factors, but the threshold of 180 mg/dL with symptoms or persistent levels above 250 mg/dL should prompt emergency evaluation.