Diabetic ketoacidosis: workup and management
DKA (2024 ADA/EASD/JBDS/AACE/DTS consensus): glucose ≥200 mg/dL or known diabetes, ketonemia (β-hydroxybutyrate ≥3.0 mmol/L) and acidosis (pH <7.3 or bicarbonate <18 mEq/L). Priorities are fluids, potassium, insulin, and finding the trigger.
Working diagnosis
Adult · US guidelines
Draft · awaiting physician review
01Orient
What's new in the evidence
- 2024 hyperglycemic crises consensus: DKA glucose threshold lowered to ≥200 mg/dL (or any glucose with known diabetes); euglycemic DKA with SGLT2 inhibitors recognized
- Hold insulin and give potassium if K <3.5 mEq/L (previously 3.3)
- When glucose falls below 250 mg/dL, add dextrose and reduce insulin to 0.05 unit/kg/h; continue until ketoacidosis resolves
- Mild to moderate uncomplicated DKA can be treated with subcutaneous rapid-acting insulin every 1–2 hours in suitable settings
- Start basal insulin early (0.15–0.3 unit/kg) and give it 2–4 hours before stopping the IV infusion
Differential diagnoses
- DKA (type 1 or ketosis-prone type 2)
- Euglycemic DKA (SGLT2 inhibitors, pregnancy, starvation)
- Hyperosmolar hyperglycemic state (may overlap)
- Alcoholic or starvation ketoacidosis
- Other high anion gap acidosis: lactate, toxins, uremia
02Assess
Risk scores and decision tools
- DKA severity: mild (pH 7.25–7.30), moderate (7.0–7.24), severe (<7.0)
- Anion gap and β-hydroxybutyrate for resolution
- Corrected sodium to guide fluid choice
Key history questions
- Polyuria, polydipsia, vomiting, abdominal pain
- Missed insulin, pump failure
- Infection symptoms, chest pain
- SGLT2 inhibitor use
- Alcohol or drug use
- Pregnancy
Examination findings
- Dehydration, tachycardia, hypotension
- Kussmaul breathing, ketotic breath
- Reduced consciousness
- Source of infection
03Investigate
Initial investigations
- Glucose, β-hydroxybutyrate
- Venous blood gas (pH, bicarbonate)
- BMP with anion gap, potassium, phosphate, magnesium
- CBC, urinalysis
- ECG (potassium effects, ischemia)
- Pregnancy test where relevant
Advanced investigations
- Blood and urine cultures, chest X-ray if infection suspected
- Troponin, lipase as indicated
- Serum osmolality (HHS overlap)
04Treat
Immediate management
- Isotonic crystalloid (balanced or 0.9% saline) 1–1.5 L in the first hour, then 250–500 mL/h guided by volume status
- Check potassium before insulin: if K <3.5 mEq/L, give potassium (about 10 mEq/h) and hold insulin until K ≥3.5
- Fixed-rate IV insulin 0.1 unit/kg/h (bolus optional)
- Add 20–30 mEq potassium per liter of fluid when K is 3.5–5.0 mEq/L
First-line treatment
- When glucose <250 mg/dL: add dextrose (D5 or D10) and reduce insulin to 0.05 unit/kg/h; continue until ketoacidosis resolves
- Start or continue basal insulin 0.15–0.3 unit/kg SC during the infusion
- Treat the trigger (infection, MI, missed insulin, SGLT2 inhibitor)
- Resolution: β-hydroxybutyrate <0.6 mmol/L and pH ≥7.3 or bicarbonate ≥18 mEq/L
Second-line treatment
- Bicarbonate only if pH under 7.0
- Phosphate replacement if under 1.0 mg/dL or with cardiac or respiratory compromise
- Subcutaneous rapid-acting insulin protocols for mild uncomplicated DKA
Specialist referrals
- Endocrinology or diabetes team before discharge
- ICU for severe DKA, shock, reduced consciousness or K under 3.3
05Disposition
Admission criteria
- All DKA requires admission
- Severe DKA (pH under 7.0, altered mentation) to ICU or step-down
Safe discharge criteria
- DKA resolved and eating
- On a stable subcutaneous regimen
- Insulin supplies, education and follow-up in place
Follow-up timing
- Diabetes team contact within 1-2 weeks
Patient instructions
- Sick-day rules: never stop basal insulin; check ketones when unwell
- Return with vomiting, abdominal pain or ketones ≥1.5 mmol/L
Monitoring
- Glucose hourly
- BMP and VBG every 2-4 h
- Ketones every 2-4 h
Clinical pearls and pitfalls
- Give subcutaneous basal insulin 1-2 h before stopping the IV infusion
- Total body potassium is depleted even when serum K is normal or high
- Euglycemic DKA on SGLT2 inhibitors is easy to miss: check ketones
RefGuidelines and landmark evidence
For education only. Typical adult starting points; confirm doses against renal function, allergies, interactions and your institution's protocols. Not a substitute for clinical judgment or senior review.