How to manage a patient with Diabetic Ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis (DKA)

Begin with aggressive isotonic saline resuscitation at 15-20 mL/kg/hour for the first hour, followed by continuous IV insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, and continue insulin until complete resolution of ketoacidosis regardless of glucose levels. 1, 2

Initial Assessment and Diagnosis

Diagnostic Criteria:

• Blood glucose >250 mg/dL 2
• Arterial pH <7.3 2
• Serum bicarbonate <15 mEq/L 2
• Presence of ketonemia or ketonuria 2

Essential Laboratory Evaluation:

• Plasma glucose, electrolytes with calculated anion gap, serum ketones, arterial blood gases, complete blood count, electrocardiogram 2, 3
• Blood urea nitrogen/creatinine, osmolality, urinalysis with urine ketones 2, 3
• Obtain bacterial cultures (blood, urine, throat) if infection suspected and administer appropriate antibiotics 2, 3
• Identify precipitating factors: infection, myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use 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) 1, 2, 3
• This aggressive initial fluid replacement is critical for restoring tissue perfusion and improving insulin sensitivity 1

Subsequent Fluid Management:

• Adjust fluid choice based on hydration status, serum electrolyte levels, and urine output 2
• When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 2
• Total fluid replacement should correct estimated deficits within 24 hours 2

Potassium Management (Critical Safety Step)

ABSOLUTE CONTRAINDICATION: Do not start insulin if K+ <3.3 mEq/L 2, 3

Potassium Replacement Algorithm:

• If K+ <3.3 mEq/L: Delay insulin therapy and aggressively replace potassium with 20-40 mEq/L in IV fluids until K+ ≥3.3 mEq/L to prevent life-threatening arrhythmias and respiratory muscle weakness 2, 3
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L 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 2
• Target: Maintain serum potassium 4-5 mEq/L throughout treatment 2, 3

Rationale: Despite potential hyperkalemia on presentation, total body potassium depletion is universal in DKA, and insulin therapy will further lower serum potassium 2

Insulin Therapy

For Critically Ill and Moderate-to-Severe DKA:

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour (preferred method) 1, 2, 3
• An initial IV bolus of 0.1 units/kg may be given 2, 3
• If glucose does not fall by 50 mg/dL in first hour, check hydration status; if acceptable, double insulin infusion rate hourly until steady decline of 50-75 mg/dL/hour achieved 2
• 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

For Mild-to-Moderate Uncomplicated DKA:

• Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin 1, 2
• However, continuous IV insulin remains standard of care for critically ill and mentally obtunded patients 1, 2

Monitoring During Treatment

Frequency:

• Draw blood every 2-4 hours to measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2, 3
• Check blood glucose every 2-4 hours 3
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 2

Preferred Method:

• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method, which only measures acetoacetic acid and acetone 2

Resolution Criteria

DKA is resolved when ALL of the following are met:

• Glucose <200 mg/dL 1, 2
• Serum bicarbonate ≥18 mEq/L 1, 2
• Venous pH >7.3 1, 2
• Anion gap ≤12 mEq/L 1, 2

Target glucose 150-200 mg/dL until DKA resolution parameters are met 1, 2

Transition to Subcutaneous Insulin

Critical Timing to Prevent Recurrence:

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion 1, 2, 3
• This overlap period is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2
• Once patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1, 2, 3

If Patient Remains NPO After DKA Resolution:

• Continue IV insulin and fluid replacement, supplement with subcutaneous regular insulin as needed 2

Bicarbonate Administration (Generally NOT Recommended)

Do NOT administer bicarbonate if pH >6.9-7.0 1, 2

• Studies show no difference in resolution of acidosis or time to discharge with bicarbonate use 1, 2
• May worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 2

Exception: Consider IV bicarbonate only if pH <6.9, or when pH <7.2 and/or bicarbonate <10 mEq/L pre- and post-intubation to prevent hemodynamic collapse 4

Thromboprophylaxis

DKA creates a hypercoagulable state increasing thrombosis risk 1

• Enoxaparin can be administered as part of standard hospital thromboprophylaxis protocols 1
• Start upon admission after initial fluid resuscitation has begun 1
• Monitor renal function regularly, as insulin therapy and fluid resuscitation can improve kidney perfusion and change enoxaparin clearance 1

Common Pitfalls to Avoid

Most Critical Errors:

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

Special Considerations

SGLT2 Inhibitors:

• Must be discontinued 3-4 days before any planned surgery to prevent euglycemic DKA 1, 2

Treating Underlying Cause:

• Identifying and treating precipitating factors (infection, myocardial infarction, insulin omission) is crucial for successful DKA treatment 1, 2

Discharge Planning:

• Identify outpatient diabetes care providers 2
• Ensure patient understands diabetes diagnosis, glucose monitoring, home glucose goals, and when to call healthcare professional 2
• Provide education on insulin administration, sick day management, and adherence to prevent recurrence 2