What is the management approach for diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis

Begin immediate treatment with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, and continue insulin until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels. 1, 2

Diagnostic Criteria

Confirm DKA with the following parameters 3, 2:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur with normal or mildly elevated glucose, particularly with SGLT2 inhibitor use) 1, 4
• Arterial pH <7.3 3, 2
• Serum bicarbonate <15 mEq/L 3, 2
• Positive serum or urine ketones (direct measurement of β-hydroxybutyrate is preferred over nitroprusside method) 1, 2
• Anion gap >10 mEq/L 3, 2

Initial Laboratory Evaluation

Obtain immediately 3, 2, 5:

• Plasma glucose, blood urea nitrogen/creatinine, serum ketones (β-hydroxybutyrate preferred)
• Electrolytes with calculated anion gap, osmolality
• Arterial blood gases, complete blood count with differential
• Urinalysis with urine ketones
• Electrocardiogram
• Blood, urine, and throat cultures if infection suspected 3, 2

Fluid Resuscitation Protocol

First Hour

Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) to restore intravascular volume and renal perfusion. 3, 1, 2 This aggressive initial fluid replacement is critical for improving tissue perfusion and insulin sensitivity 2.

Subsequent Fluid Management

After the first hour, fluid choice depends on corrected serum sodium 3, 2:

• If corrected sodium is normal or elevated: Use 0.45% NaCl at 4-14 mL/kg/hour 3
• If corrected sodium is low: Continue 0.9% NaCl at similar rate 3
• When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 1, 2

Critical point: In euglycemic DKA, add dextrose-containing fluids earlier in treatment to maintain adequate glucose levels while continuing insulin to clear ketosis 1.

Insulin Therapy

Timing and Dosing

Do not start insulin if potassium <3.3 mEq/L—correct potassium first to prevent life-threatening arrhythmias and respiratory muscle weakness. 2 This is a critical safety checkpoint.

Once potassium ≥3.3 mEq/L 2:

• Start continuous IV regular insulin at 0.1 units/kg/hour without initial bolus (preferred for moderate to severe DKA) 1, 2, 5
• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration, then double insulin infusion rate hourly until steady decline of 50-75 mg/h is achieved 2

Critical Management Point

Never interrupt insulin infusion when glucose levels fall—this is the most common cause of persistent or worsening ketoacidosis. 1, 2 Instead, add dextrose to IV fluids to prevent hypoglycemia while continuing insulin to clear ketones 1, 2.

Continue insulin infusion until complete resolution of ketoacidosis: pH >7.3, serum bicarbonate ≥18 mEq/L, and anion gap ≤12 mEq/L, regardless of glucose levels. 1, 2

Alternative for Mild-Moderate Uncomplicated DKA

For alert patients with mild-to-moderate DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin 2. However, continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients. 2

Electrolyte Management

Potassium Replacement

Despite often presenting with normal or elevated potassium, total body potassium depletion is universal in DKA, and insulin therapy will further lower serum potassium. 2 This makes potassium management critical to prevent mortality 2.

Potassium replacement protocol 3, 2:

• If K+ <3.3 mEq/L: Hold insulin, 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
• Target: Maintain serum potassium 4-5 mEq/L throughout treatment 1, 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, and bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 2. Consider bicarbonate only if pH <6.9 or in peri-intubation period to prevent hemodynamic collapse 6.

Phosphate

Include phosphate replacement (as part of potassium replacement using KPO₄) to prevent potential complications, though routine aggressive phosphate replacement is not required 3, 2.

Monitoring Protocol

Frequency

• Blood glucose: Every 1-2 hours 1
• Serum electrolytes, glucose, BUN, creatinine, osmolality, venous pH: Every 2-4 hours 1, 2, 5
• Venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 2

What to Monitor

Follow these parameters closely to guide therapy adjustments and identify complications early 3, 2:

• Glucose trends and rate of decline
• Potassium levels (most critical electrolyte)
• Anion gap closure
• pH normalization
• Mental status changes (cerebral edema risk)

Resolution Criteria

DKA is resolved when ALL of the following are met 1, 2:

• Glucose <200 mg/dL (or stabilized in euglycemic DKA)
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Transition to Subcutaneous Insulin

This is the most critical transition point to prevent DKA recurrence:

Administer basal insulin (intermediate or long-acting such as glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion. 2, 5 This overlap period is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia 2, 5.

Once patient can eat 2, 5:

• Start multiple-dose insulin schedule using combination of short/rapid-acting and intermediate/long-acting insulin
• Continue monitoring glucose every 2-4 hours while NPO 5

Common Pitfalls to Avoid

1. Stopping IV insulin prematurely before complete resolution of ketosis—this is the most common error leading to DKA recurrence 1, 2, 5

2. Interrupting insulin when glucose falls without adding dextrose—this perpetuates ketoacidosis 1, 2

3. Starting insulin with potassium <3.3 mEq/L—this can cause fatal arrhythmias 2

4. Inadequate potassium monitoring and replacement—a leading cause of mortality in DKA 2

5. Stopping IV insulin without prior basal insulin administration—leads to immediate DKA recurrence 5

6. Relying on nitroprusside method for ketone measurement—this doesn't detect β-hydroxybutyrate, the predominant ketone body in DKA 1, 2

7. Overly rapid correction of osmolality—increases risk of cerebral edema, particularly in children 2, 6

Special Considerations

SGLT2 Inhibitors

Discontinue SGLT2 inhibitors 3-4 days before any planned surgery to prevent euglycemic DKA 2. These medications modestly increase the risk of both typical and euglycemic DKA 4.

Euglycemic DKA

In euglycemic DKA, add dextrose-containing fluids earlier and never interrupt insulin despite normal glucose levels—insulin is needed to clear ketosis, not just to lower glucose 1.

Precipitating Factors

Identify and treat underlying causes concurrently: infection (most common), myocardial infarction, stroke, pancreatitis, trauma, or insulin omission 3, 2. Obtain appropriate cultures and start antibiotics if infection suspected 3, 2.

Site of Care

Most patients do not require intensive care unit admission and can be safely managed on medical wards with appropriate monitoring 7. Reserve ICU for critically ill, mentally obtunded patients, or those with severe comorbidities 2, 6.