What is the appropriate management for a patient presenting with diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis (DKA)

Begin immediate aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in 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 (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels. 1

Initial Assessment and Diagnosis

• Confirm DKA diagnosis with: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1
• Obtain comprehensive laboratory evaluation: plasma glucose, BUN/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality, urinalysis, urine ketones, arterial blood gases, complete blood count with differential, and electrocardiogram 1
• Direct measurement of β-hydroxybutyrate in blood is the preferred monitoring method, as nitroprusside only measures acetoacetic acid and acetone 1
• Identify precipitating factors immediately: infection (obtain bacterial cultures from urine, blood, throat if suspected), cerebrovascular accident, myocardial infarction, pancreatitis, trauma, insulin discontinuation/inadequacy, or SGLT2 inhibitor use 1

Fluid Resuscitation Protocol

• Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore intravascular volume and renal perfusion 1
• Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output 1
• When serum glucose reaches 200-250 mg/dL, switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin therapy to prevent hypoglycemia and ensure complete ketoacidosis resolution 1
• Total fluid replacement should correct estimated deficits within 24 hours 1

Insulin Therapy

For Critically Ill or Moderate-to-Severe DKA:

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour (standard of care for critically ill and mentally obtunded patients) 1
• If plasma glucose does not fall by 50 mg/dL in the first hour, check hydration status; if acceptable, double the insulin infusion rate every hour until steady glucose decline of 50-75 mg/h is achieved 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—this is critical to prevent recurrence 1
• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 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 1
• This approach requires adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 1

Critical Electrolyte Management

Potassium Replacement (Most Critical):

• If 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
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1
• 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

Bicarbonate Administration:

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

Monitoring During Treatment

• Draw blood every 2-4 hours to determine serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis 1
• Monitor potassium levels closely every 2-4 hours during active treatment, as inadequate monitoring and replacement is a leading cause of mortality in DKA 1

Resolution Criteria

• 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
• Ketonemia typically takes longer to clear than hyperglycemia 2

Transition to Subcutaneous Insulin

• Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia—this overlap period is essential 1
• Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 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 Underlying Precipitating Causes

• Administer appropriate antibiotics if infection is suspected based on bacterial cultures 1
• Manage concurrent conditions such as myocardial infarction, stroke, or pancreatitis 1
• Discontinue SGLT2 inhibitors immediately, as they must be stopped 3-4 days before any planned surgery to prevent euglycemic DKA 1

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis (all four resolution criteria met) leads to DKA recurrence 1
• Interruption of insulin infusion when glucose levels fall below 250 mg/dL is a common cause of persistent or worsening ketoacidosis—add dextrose instead 1
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 1
• Inadequate monitoring and replacement of electrolytes, particularly potassium, which is a leading cause of mortality 1
• Overzealous treatment with insulin without glucose supplementation can lead to hypoglycemia 1
• Overly rapid correction of osmolality increases the risk of cerebral edema, particularly in children 1
• Inadequate fluid resuscitation can worsen DKA 2

Discharge Planning

• Schedule outpatient follow-up with primary care provider, endocrinologist, or diabetes educator within 1 month of discharge 3
• If glycemic medications are changed or glucose control is not optimal at discharge, schedule an earlier appointment (in 1-2 weeks) 3
• Educate patients and families on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia, and when to call healthcare professionals 1
• Identify outpatient diabetes care providers before discharge 1