What is the initial treatment for acute diabetic ketoacidosis (DKA)?

Initial Treatment for Acute Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour, while simultaneously addressing potassium replacement and identifying precipitating factors. 1, 2

Immediate Fluid Resuscitation (First Priority)

Start with aggressive volume expansion using isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in the average adult) during the first hour to restore intravascular volume and renal perfusion. 3, 1, 2 This initial bolus is critical regardless of cardiac status in most patients, as DKA typically causes 6L (100 mL/kg) total body fluid deficit. 2

• After the first hour, switch to 0.45% NaCl at 4-14 mL/kg/hour if corrected serum sodium is normal or elevated; continue 0.9% NaCl if corrected sodium is low. 1
• Total fluid replacement should correct the estimated deficit within 24 hours. 2
• Critical exception: In anuric end-stage renal disease patients with congestive heart failure, severely restrict or eliminate fluid boluses entirely and initiate urgent hemodialysis instead, as standard fluid resuscitation causes life-threatening pulmonary edema. 4

Insulin Therapy (Second Priority)

Administer continuous IV regular insulin at 0.1 units/kg/hour without an initial bolus to avoid precipitating cerebral edema and worsening hypokalemia. 1 The American Diabetes Association gives this Grade A recommendation. 3

• Some protocols include an initial IV bolus of 0.15 U/kg, but the no-bolus approach is increasingly preferred to minimize complications. 2
• Never interrupt insulin infusion until DKA is completely resolved, even when glucose falls to target range. 1
• When glucose reaches 150-200 mg/dL (some sources say 200-250 mg/dL), add 5% dextrose to IV fluids (with 0.45-0.75% NaCl) but continue insulin infusion to clear ketoacidosis. 1, 4
• Continue insulin until all resolution criteria are met: glucose <200 mg/dL, bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L. 1, 2

Critical Potassium Management (Concurrent Priority)

If initial potassium is <3.3 mEq/L, delay insulin therapy until potassium is repleted above 3.3 mEq/L to prevent life-threatening cardiac arrhythmias, cardiac arrest, and respiratory muscle weakness. 3, 1 This is a life-or-death decision point.

• Despite total body potassium depletion, patients often present with mild-to-moderate hyperkalemia due to acidosis and insulin deficiency. 3
• Once potassium falls below 5.5 mEq/L (assuming adequate urine output), add 20-40 mEq/L potassium to each liter of IV fluid, using 2/3 KCl and 1/3 KPO₄. 3, 1, 2
• Target serum potassium of 4-5 mEq/L throughout treatment. 1

Initial Laboratory Evaluation

Obtain immediately: 3, 2

• Plasma glucose, electrolytes with calculated anion gap, arterial or venous blood gases
• Serum ketones (beta-hydroxybutyrate preferred over urine ketones), osmolality
• Blood urea nitrogen, creatinine, complete blood count with differential
• Urinalysis with urine ketones
• Electrocardiogram
• Cultures (blood, urine, throat) if infection suspected
• HbA1c to distinguish acute versus chronic poor control

Bicarbonate Therapy: Generally Contraindicated

Do NOT administer bicarbonate if pH is ≥7.0, as studies show no benefit on clinical outcomes and potential harm. 3, 1 This is a Grade B recommendation from the American Diabetes Association. 3

• Only consider bicarbonate if pH <6.9 after initial treatment: give 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/hour. 3
• If pH 6.9-7.0, consider 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/hour. 3
• Absolutely contraindicated in mixed DKA with concurrent alkalosis. 1

Monitoring Protocol

• Check blood glucose every 1-2 hours initially. 1, 4
• Draw electrolytes, glucose, BUN, creatinine, osmolality, and venous pH every 2-4 hours. 1
• Venous pH (typically 0.03 units lower than arterial) can replace repeated arterial blood gases. 1
• Continuous cardiac monitoring if significant potassium abnormalities present. 4

Identify and Treat Precipitating Factors

Common triggers include: 3, 2, 4

• Infection (most common precipitating factor—obtain cultures and start empiric antibiotics if suspected)
• Insulin omission or inadequate dosing in established type 1 diabetes
• New-onset type 1 diabetes
• Myocardial infarction, cerebrovascular accident, pancreatitis, trauma
• Drugs: corticosteroids, thiazides, sympathomimetics (dobutamine, terbutaline), SGLT2 inhibitors
• Alcohol abuse

Transition to Subcutaneous Insulin

Administer subcutaneous basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin to prevent rebound ketoacidosis and hyperglycemia. 1, 4 This overlap period is essential.

• For newly diagnosed patients, start with approximately 0.5-1.0 U/kg/day as a multidose regimen of short- and intermediate-/long-acting insulin. 3, 4
• For established patients, resume their previous regimen with adjustments based on the acute episode. 3

Critical Pitfalls to Avoid

• Never stop insulin when glucose normalizes—ketoacidosis takes longer to resolve than hyperglycemia; add dextrose instead. 1
• Never give insulin if potassium <3.3 mEq/L—this causes fatal arrhythmias. 3, 1
• Never correct osmolality too rapidly (keep changes <3 mOsm/kg/hour) to prevent cerebral edema, especially in children. 4
• Never give standard fluid boluses to anuric ESRD patients with CHF—use hemodialysis instead. 4
• Hypothermia is a poor prognostic sign despite infection being present. 3
• Abdominal pain may be either cause or consequence of DKA—reevaluate if it doesn't resolve with treatment. 3