What is the immediate treatment for a patient presenting with Diabetic Ketoacidosis (DKA)?

Immediate Treatment of Diabetic Ketoacidosis

Begin aggressive fluid resuscitation with isotonic saline at 15-20 mL/kg/hour in the first hour, followed by continuous intravenous insulin infusion at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while simultaneously replacing electrolytes and identifying the underlying precipitating cause. 1, 2, 3

Initial Assessment and Stabilization

Diagnostic Confirmation

• Confirm DKA diagnosis with: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 3
• Obtain immediate laboratory evaluation including plasma glucose, electrolytes with calculated anion gap, arterial blood gases, serum ketones (β-hydroxybutyrate preferred), BUN/creatinine, complete blood count, urinalysis, and electrocardiogram 2, 3
• If infection suspected, obtain bacterial cultures from urine, blood, and throat before administering appropriate antibiotics 2, 3

Fluid Resuscitation Protocol

• Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) during the first hour to restore intravascular volume and tissue perfusion 1, 2, 3
• When serum glucose reaches 200-250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution 3
• Total fluid replacement should correct estimated deficits within 24 hours 2

Insulin Therapy

Critical Pre-Insulin Check

• DO NOT start insulin if serum potassium is <3.3 mEq/L—this is an absolute contraindication that can cause life-threatening cardiac arrhythmias and death 2, 3
• If K+ <3.3 mEq/L, delay insulin and aggressively replace potassium until levels reach ≥3.3 mEq/L 2, 3

Insulin Initiation and Dosing

• Once K+ ≥3.3 mEq/L, administer IV bolus of regular insulin at 0.1 units/kg, followed by continuous infusion at 0.1 units/kg/hour 2, 4
• Target glucose decline of 50-75 mg/dL/hour 2, 3
• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration, then double the insulin infusion rate hourly until steady decline achieved 3
• Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1, 2, 3

Alternative Approach for Mild-Moderate Uncomplicated DKA

• For uncomplicated mild-moderate DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 5, 3
• This approach requires adequate fluid replacement, frequent point-of-care glucose monitoring every 2-4 hours, and treatment of concurrent infections 5, 3
• Continuous IV insulin remains the standard of care for critically ill and mentally obtunded patients 5, 1, 3

Electrolyte Management

Potassium Replacement Protocol

• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 2, 3
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 3
• Target serum potassium of 4-5 mEq/L throughout treatment 2, 3
• Monitor potassium levels every 2-4 hours, as insulin drives potassium intracellularly and inadequate replacement is a leading cause of mortality in DKA 2, 3

Bicarbonate Administration

• Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0 5, 3
• Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 5, 3
• Bicarbonate may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 3

Monitoring During Treatment

• Draw blood every 2-4 hours to measure serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 2, 3
• Check blood glucose every 2-4 hours while patient is NPO 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 3
• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method for monitoring DKA 3

Resolution Criteria and Transition

DKA Resolution Parameters

• DKA is resolved when ALL of the following are met: glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L 1, 3
• Target glucose between 150-200 mg/dL until these resolution parameters are met 1, 3

Transition to Subcutaneous Insulin

• Administer basal insulin (glargine, detemir, or NPH) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia—this is the most common error leading to DKA recurrence 5, 2, 3
• Once patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 2, 3
• Adding low-dose basal insulin analog during IV insulin infusion may help prevent rebound hyperglycemia without increasing hypoglycemia risk 5, 3

Treatment of Underlying Precipitating Causes

• Identify and treat correctable underlying causes: sepsis, myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or medication-induced (especially SGLT2 inhibitors) 5, 3
• SGLT2 inhibitors must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA 3
• Administer appropriate antibiotics if infection is suspected based on cultures 2, 3

Critical Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis causes DKA recurrence 3
• Stopping IV insulin without prior basal insulin administration leads to rebound ketoacidosis 2, 3
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 3
• Starting insulin when potassium is <3.3 mEq/L can cause fatal arrhythmias 2, 3
• Inadequate potassium monitoring and replacement is a leading cause of mortality 3
• Overly rapid correction of osmolality increases cerebral edema risk, particularly in children 3