Glucose
Background
- Primary energy substrate for the brain and red blood cells
- Point-of-care (fingerstick) glucose is a bedside test; serum glucose is measured on chemistry panels
Normal Values
- Fasting: 70-100 mg/dL
- Random: 70-140 mg/dL
- Hypoglycemia: <70 mg/dL
- Diabetic emergency thresholds: DKA typically >250 mg/dL; HHS typically >600 mg/dL
Interpretation
- Check fingerstick glucose on all patients with altered mental status, seizures, or focal neurologic deficits
- Hypoglycemia is the most important "do not miss" glucose abnormality in the ED
- Causes: insulin/sulfonylurea use, sepsis, liver failure, adrenal insufficiency, alcohol
- Treat: IV dextrose (D50 or D10), oral glucose if able to swallow safely
- Stress hyperglycemia is common in acutely ill patients and does not necessarily indicate diabetes
- Serum glucose may differ from fingerstick by up to 10-15%