Immediate Treatment of Diabetic Ketoacidosis
Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour in the first hour, followed immediately by continuous intravenous insulin infusion at 0.1 units/kg/hour, while simultaneously monitoring and replacing potassium to maintain levels between 4-5 mEq/L. 1, 2
Initial Assessment and Diagnostic Confirmation
Before initiating treatment, confirm DKA diagnosis with the following criteria 2:
- Blood glucose >250 mg/dL
- Arterial pH <7.3
- Serum bicarbonate <15 mEq/L
- Presence of ketonemia or ketonuria
Obtain immediate laboratory evaluation including plasma glucose, electrolytes with calculated anion gap, serum ketones (preferably β-hydroxybutyrate), arterial blood gases, BUN/creatinine, osmolality, urinalysis, complete blood count, and electrocardiogram 2.
Critical: Check potassium level immediately—if K+ <3.3 mEq/L, do NOT start insulin therapy until potassium is corrected to ≥3.3 mEq/L to prevent life-threatening cardiac arrhythmias. 2
Fluid Resuscitation Protocol
Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adults) during the first hour to restore circulating volume and tissue perfusion. 1, 2 This aggressive initial fluid replacement is critical as it improves insulin sensitivity and helps correct the metabolic derangement 2.
After the initial hour, adjust fluid rate based on hydration status, serum electrolyte levels, and urine output 2. The goal is to correct estimated fluid deficits within 24 hours 2.
When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin infusion. 1, 2 This prevents hypoglycemia while allowing continued insulin therapy to resolve ketoacidosis 1.
Insulin Therapy
Initiate continuous intravenous regular insulin infusion at 0.1 units/kg/hour immediately after confirming adequate potassium levels (≥3.3 mEq/L). 1, 2 This is the standard of care for critically ill and mentally obtunded patients with DKA 3, 2.
If plasma glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration status; if acceptable, double the insulin infusion rate hourly until achieving a steady glucose decline of 50-75 mg/hour 2.
Continue insulin infusion until complete resolution of ketoacidosis regardless of glucose levels—this is crucial. 1, 2 Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1, 2.
Common Pitfall to Avoid
Never stop insulin infusion when glucose levels fall—this is a leading cause of persistent or worsening ketoacidosis. 1 Instead, add dextrose to IV fluids and continue insulin therapy until ketoacidosis resolves 1, 2.
Electrolyte Management
Potassium Replacement (Critical)
Despite often presenting with normal or elevated potassium, total body potassium depletion is universal in DKA 2. Insulin therapy will further lower serum potassium 2.
Follow this potassium replacement algorithm 2:
- If K+ <3.3 mEq/L: Hold insulin therapy and aggressively replace potassium until ≥3.3 mEq/L
- If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed
- If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely as levels will drop rapidly with insulin therapy
Target serum potassium of 4-5 mEq/L throughout treatment. 1, 2 Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 2.
Bicarbonate Administration
Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0. 2 Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 3, 2.
Monitoring During Treatment
Draw blood every 2-4 hours to measure serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH. 1, 2 Venous pH is sufficient for monitoring (typically 0.03 units lower than arterial pH) and avoids repeated arterial punctures 4, 2.
Follow the anion gap in parallel with pH to confirm ketoacid clearance 4.
Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone, not β-hydroxybutyrate 4, 2.
Resolution Criteria
DKA is resolved when ALL of the following criteria are met 1, 4, 2:
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3
- Anion gap ≤12 mEq/L
Note that ketonemia typically takes longer to clear than hyperglycemia, necessitating continued insulin therapy even after glucose normalizes 1, 4.
Transition to Subcutaneous Insulin
Once DKA is resolved, administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 3, 2 This overlap period is essential 2.
When the patient is able to eat, start a multiple-dose subcutaneous insulin regimen combining short/rapid-acting and intermediate/long-acting insulin 3, 4, 2.
Treatment of Underlying Precipitating Cause
Identify and treat any underlying precipitating event concurrently, such as 3, 2:
- Infection (obtain cultures and administer appropriate antibiotics if indicated)
- Myocardial infarction
- Stroke
- Medication non-adherence
- SGLT2 inhibitor use (discontinue immediately)
Special Considerations
Mild-to-Moderate Uncomplicated DKA
For uncomplicated mild-to-moderate DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin 2, 5. However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients 3, 2.
Euglycemic DKA
In euglycemic DKA (glucose <250 mg/dL with ketoacidosis, often associated with SGLT2 inhibitors), start 5% dextrose alongside 0.9% NaCl at the beginning of insulin treatment 1. SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent this variant 2.