What is the initial management of Diabetic Ketoacidosis (DKA) in the emergency department?

Initial Management of Diabetic Ketoacidosis in the Emergency Department

Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour (with or without a 0.1 units/kg bolus), while simultaneously correcting electrolyte abnormalities and identifying the precipitating cause. 1, 2, 3

Initial Assessment and Laboratory Evaluation

Obtain the following labs immediately upon presentation:

• Plasma glucose, serum ketones (β-hydroxybutyrate preferred), arterial blood gas 1, 3
• Complete metabolic panel with calculated anion gap and osmolality 1, 2
• Blood urea nitrogen, creatinine, complete blood count 1, 2
• Urinalysis with urine ketones, electrocardiogram 1, 2
• Bacterial cultures (blood, urine, throat) if infection suspected 2

Diagnostic criteria confirming DKA: plasma glucose >250 mg/dL, arterial pH <7.30, serum bicarbonate <18 mEq/L, and positive serum/urine ketones 1

Fluid Resuscitation Protocol

First hour: Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour to restore intravascular volume and renal perfusion 1, 2, 3

Subsequent hours: Continue fluid replacement targeting 1.5-2 times the 24-hour maintenance requirements to correct estimated deficits within 24 hours 1, 2

When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin therapy to resolve ketosis 3

Recent evidence suggests balanced crystalloid solutions may achieve faster DKA resolution compared to normal saline, though isotonic saline remains the guideline standard 4

Insulin Therapy

For Critically Ill or Obtunded Patients:

Continuous IV regular insulin is the standard of care 5, 3

Dosing options:

• Option 1 (preferred for adults): 0.1 units/kg IV bolus, then 0.1 units/kg/hour continuous infusion 3
• Option 2: Start directly at 0.1 units/kg/hour without bolus 1

Critical prerequisite: Confirm serum potassium ≥3.3 mEq/L before starting insulin to prevent life-threatening hypokalemia 3

If glucose fails to decrease by 50 mg/dL in the first hour: Double the insulin infusion rate hourly until achieving steady decline of 50-75 mg/hour 1, 3

For Uncomplicated Mild-Moderate DKA:

Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be used in the ED or step-down units, which can be safer and more cost-effective than IV insulin 5, 3

Important caveat: This approach requires adequate nurse training, frequent bedside glucose testing, and appropriate follow-up 5

Electrolyte Management

Potassium Replacement (Critical Priority):

Monitor potassium closely—insulin therapy drives potassium intracellularly and can cause life-threatening hypokalemia 1, 3

Replacement protocol:

• Once renal function confirmed and serum potassium <5.3 mEq/L, add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1, 2, 3
• Target serum potassium 4-5 mmol/L throughout treatment 3
• Hypokalemia occurs in approximately 43% of patients 6

Other Electrolytes:

Monitor for hypophosphatemia and hypomagnesemia, which frequently occur in DKA 4

Monitoring During Treatment

Blood glucose: Check every 1-2 hours 1, 3

Comprehensive metabolic panel: Draw every 2-4 hours to assess electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 1, 2, 3

Follow venous pH and anion gap to monitor resolution of acidosis 1, 3

β-hydroxybutyrate measurement is preferred over nitroprusside method, which only detects acetoacetic acid and acetone 3

Resolution Criteria and Transition

DKA is resolved when ALL of the following are met:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L 1, 2, 3

Critical transition step: Administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping IV insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2, 3

Recent evidence suggests adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 3, 4

Common Pitfalls to Avoid

Do not stop IV insulin without prior basal insulin administration—this is the most common error leading to DKA recurrence 2

Do not use bicarbonate routinely—multiple studies show no benefit in resolution of acidosis or time to discharge, and it may worsen ketosis, hypokalemia, and increase cerebral edema risk 5, 4

Exception for bicarbonate: Consider only if pH <6.9, or when pH <7.2 pre/post-intubation to prevent hemodynamic collapse 4

Ketonemia clears slower than hyperglycemia—continue insulin until ketoacidosis resolves even if glucose normalizes 3

Monitor for hypoglycemia—occurs in approximately 14% of patients 6

Identify and Treat Precipitating Causes

Most common triggers:

• Treatment discontinuation (42% of cases) 6
• Infection (32% of cases) 6
• Myocardial infarction, stroke, sepsis 3

SGLT2 inhibitor consideration: Discontinue 3-4 days before surgery and monitor for euglycemic DKA (can occur with normal or mildly elevated glucose) 1

Administer appropriate antibiotics if infection identified 2

Special Populations

Pediatric Patients:

Do NOT give initial insulin bolus—start directly with continuous infusion at 0.1 units/kg/hour 3

Older Adults:

Consider that patients ≥80 years are five times more likely to be admitted for insulin-related hypoglycemia; oral therapy may be safer than insulin for some patients 5

Pregnancy, Renal Disease, Heart Failure:

These comorbidities require tailored fluid and insulin strategies, though specific guideline recommendations are limited 7

Discharge Planning

Begin structured discharge planning at admission, including:

• Medication reconciliation 3
• Patient education on insulin administration, glucose monitoring, and sick day management 2
• Schedule outpatient follow-up before discharge to enhance appointment-keeping 5, 3
• Transmit discharge summary to primary physician immediately 5, 3