Emergency Department · CCS Case Walkthrough
Altered Mental Status — Diabetic Ketoacidosis
32-year-old female with Type 1 diabetes presents with confusion, rapid deep breathing, fruity breath odor, nausea, vomiting, and abdominal pain. Last insulin dose was 2 days ago.
Step-by-Step Approach
- Immediate glucose check (point-of-care and confirm with lab)
- Order ABG or VBG, BMP (anion gap, potassium), CBC, urinalysis, beta-HCG
- Start aggressive IV fluid resuscitation — NS 1L bolus then 250–500 mL/hr
- Start insulin drip at 0.1 units/kg/hr (do NOT bolus in mild DKA)
- Check potassium BEFORE starting insulin — replace if < 3.3
- Monitor glucose hourly, BMP every 2–4 hours
- Switch to D5 1/2 NS when glucose < 200, continue insulin until anion gap closes
- Identify precipitant — infection, missed insulin, new-onset
- Transition to subcutaneous insulin when eating and gap closed
Common Orders Checklist
✓Fingerstick glucose
✓BMP (stat)
✓ABG or VBG
✓CBC
✓Urinalysis
✓Beta-HCG
✓Blood cultures
✓Chest X-ray
✓ECG
✓NS 1L bolus
✓Insulin drip 0.1 u/kg/hr
✓Potassium replacement
✓Hourly glucose checks
✓BMP every 2–4 hours
✓Phosphate level
✓Telemetry monitoring
Common Pitfalls
- ⚠Starting insulin before checking potassium — can cause fatal hypokalemia
- ⚠Giving an insulin bolus (not recommended in most current protocols)
- ⚠Not switching to dextrose-containing fluids when glucose drops below 200
- ⚠Stopping insulin drip based on glucose alone — must wait for anion gap closure
- ⚠Forgetting to look for the precipitant (UTI, pneumonia, MI, non-compliance)
Related Topics
Hyperosmolar Hyperglycemic StateSepsisHypokalemia