What is the management approach for a patient with Diabetic Ketoacidosis (DKA), assumed to have a history of diabetes?

Management of Diabetic Ketoacidosis (DKA)

Initial Assessment and Diagnosis

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 liters in the first hour) while simultaneously obtaining diagnostic laboratories. 1, 2

Diagnostic Criteria

• Blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1
• Obtain plasma glucose, blood urea nitrogen/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality, urinalysis, urine ketones, arterial blood gases, complete blood count with differential, and electrocardiogram 1, 2
• Identify precipitating factors: infection (obtain bacterial cultures from urine, blood, throat if suspected), myocardial infarction, stroke, pancreatitis, trauma, insulin omission/inadequacy, or SGLT2 inhibitor use 1, 2

Fluid Resuscitation Protocol

Continue isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore intravascular volume and renal perfusion. 1, 2

• After the first hour, adjust fluid choice based on corrected serum sodium: use 0.45% NaCl at 4-14 mL/kg/hour if corrected sodium is normal or elevated; continue 0.9% NaCl if corrected sodium is low 2
• When serum glucose reaches 200-250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution. 1, 2
• Total fluid replacement should correct estimated deficits within 24 hours 1

Insulin Therapy

For Severe or Critically Ill Patients

Continuous intravenous regular insulin at 0.1 units/kg/hour is the standard of care for moderate-to-severe DKA or critically ill/mentally obtunded patients. 3, 1

• If plasma glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration; if acceptable, double the insulin infusion rate hourly until achieving steady glucose decline of 50-75 mg/dL per hour 1
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1
• Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels. 1

For Mild-to-Moderate Uncomplicated DKA

Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin for hemodynamically stable, alert patients with mild-moderate uncomplicated DKA. 3, 1

• This approach requires adequate fluid replacement, frequent point-of-care glucose monitoring, treatment of concurrent infections, and appropriate follow-up 1
• Continuous IV insulin remains mandatory for critically ill and mentally obtunded patients 1

Electrolyte Management

Potassium Replacement (Critical)

Total body potassium depletion averages 3-5 mEq/kg body weight in DKA, and insulin therapy will unmask this depletion by driving potassium intracellularly. 1

• If serum K+ <3.3 mEq/L, delay insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias and respiratory muscle weakness. 1
• 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 is confirmed 1, 2
• If K+ >5.5 mEq/L, withhold potassium initially but monitor closely every 2-4 hours, as levels will drop rapidly with insulin therapy 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0, as multiple studies show no difference in resolution of acidosis or time to discharge, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 3, 1, 2

Monitoring During Treatment

• Check blood glucose every 1-2 hours until stable 2
• Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA 1

Resolution Criteria

DKA is resolved when glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L. 1, 2

Transition to Subcutaneous Insulin

Administer basal insulin (intermediate or long-acting such as glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 3, 1, 2

• This overlap period is essential and non-negotiable 1
• Once the patient can eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 1
• If the patient remains NPO after DKA resolution, continue IV insulin and fluid replacement, supplementing with subcutaneous regular insulin as needed 1

Treatment of Precipitating Factors

Identify and treat correctable underlying causes concurrently, such as sepsis (administer appropriate antibiotics), myocardial infarction, stroke, pancreatitis, or discontinue precipitating medications. 1, 2

• SGLT2 inhibitors must be discontinued immediately and not restarted until 3-4 days after metabolic stability is achieved to prevent recurrent or euglycemic DKA. 1

Critical Pitfalls to Avoid

• Stopping IV insulin without prior administration of basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis 1
• Premature termination of insulin therapy before complete resolution of ketosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) leads to recurrence 1
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy results in hypoglycemia and interrupts ketoacidosis resolution 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1
• Overly rapid correction of osmolality (exceeding 3 mOsm/kg/hour) increases risk of cerebral edema, particularly in children and adolescents 1
• Starting insulin when K+ <3.3 mEq/L can precipitate fatal cardiac arrhythmias 1

Special Considerations

Cardiac Dysfunction or Pleural Effusions

• Avoid excessive fluid administration which may worsen pulmonary edema and pleural effusions 4
• Consider thoracentesis for bilateral pleural effusions if contributing significantly to respiratory compromise 4
• Position patient upright (if hemodynamically stable) to improve lung expansion 4

Renal Dysfunction

• Confirm adequate urine output before aggressive potassium repletion; if anuric or oliguric, potassium repletion must be more cautious with nephrology consultation 1