What is the appropriate management for a 56-year-old female patient presenting with severe hyperglycemia and ketonuria, indicative of diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis

This patient requires immediate hospitalization with aggressive IV fluid resuscitation, continuous IV insulin infusion, and close electrolyte monitoring—this is a medical emergency with significant mortality risk if not treated promptly and appropriately. 1

Immediate Diagnostic Confirmation

Before initiating treatment, obtain the following laboratory studies immediately: 1

• Complete metabolic panel including serum bicarbonate, electrolytes, BUN, creatinine 1
• Venous blood gas to assess pH and severity 1
• Direct measurement of β-hydroxybutyrate in blood (preferred over urine ketones) 1
• Calculate anion gap: [Na⁺] - ([Cl⁻] + [HCO₃⁻]) 1
• Complete blood count, urinalysis, and ECG 2
• Bacterial cultures (urine, blood, throat) if infection suspected 1, 2

With glucose 565 mg/dL and significant ketonuria, this patient meets criteria for DKA if pH <7.3 and bicarbonate <15 mEq/L. 1 The severity classification depends on these values: mild (pH 7.25-7.30), moderate (pH 7.00-7.24), or severe (pH <7.00). 1

Initial Fluid Resuscitation

Begin aggressive fluid resuscitation immediately—this is the first priority: 1, 2

• Start isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour 1, 2
• After initial volume expansion, adjust fluid choice based on corrected serum sodium: 1
  • If corrected sodium is normal or elevated: use 0.45% NaCl at 4-14 mL/kg/hour 3
  • If corrected sodium is low: continue 0.9% NaCl at similar rate 3
• Correct serum sodium for hyperglycemia: add 1.6 mEq/L for every 100 mg/dL glucose above 100 1, 2
• Total fluid replacement should correct estimated deficits within 24 hours 1, 3

Critical Potassium Management

Check serum potassium BEFORE starting insulin—this is life-saving: 2

• If K⁺ <3.3 mEq/L: DO NOT start insulin; aggressively replace potassium first to prevent fatal cardiac arrhythmias 1, 2
• If K⁺ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 1, 2
• If K⁺ >5.5 mEq/L: Hold potassium replacement but recheck frequently 2
• Target serum potassium 4-5 mEq/L throughout treatment 1, 2

Insulin Therapy Protocol

Once potassium ≥3.3 mEq/L, initiate continuous IV regular insulin: 1, 2

• Start with 0.1 units/kg IV bolus, followed by continuous infusion at 0.1 units/kg/hour 2
• Target glucose decline of 50-75 mg/dL per hour 1, 2
• If glucose does not fall by 50 mg/dL in first hour, verify adequate hydration, then double insulin infusion rate hourly until steady decline achieved 1, 2

Critical transition point when glucose reaches 200-250 mg/dL: 1, 3

• Add 5-10% dextrose to IV fluids while continuing insulin infusion 1, 3
• This is essential—insulin alone cannot clear ketones without carbohydrate substrate 1
• Continue insulin at 0.05-0.1 units/kg/hour to resolve ketoacidosis 1, 3
• Do NOT stop insulin when glucose normalizes—ketoacidosis takes longer to resolve than hyperglycemia 1, 3

Monitoring Protocol

Draw blood every 2-4 hours to measure: 1, 3

• Glucose, electrolytes (especially potassium), BUN, creatinine 1
• Venous pH and calculate anion gap 1
• β-hydroxybutyrate (preferred over urine ketones for monitoring) 1

Common pitfall to avoid: Do not rely on urine ketones or nitroprusside tests for monitoring treatment response—these only measure acetoacetate and acetone, not β-hydroxybutyrate (the predominant ketoacid), and can paradoxically worsen during treatment even as the patient improves. 1

Resolution Criteria

DKA is resolved when ALL of the following are met: 1, 3, 2

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

Transition to Subcutaneous Insulin

Once DKA is resolved AND patient can tolerate oral intake: 1, 2

• Administer basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE stopping IV insulin 1, 2
• This timing is critical to prevent rebound hyperglycemia and recurrent ketoacidosis 1, 2
• Continue IV insulin for 1-2 hours after subcutaneous dose given 2
• Start multiple-dose regimen combining short/rapid-acting with intermediate/long-acting insulin 2

Most common error leading to DKA recurrence: Stopping IV insulin without prior basal insulin administration. 2

Special Considerations

Bicarbonate therapy: Generally NOT recommended unless pH <6.9 1, 3

If patient has altered mental status or severe DKA (pH <7.00): 1

• May require ICU-level monitoring with central venous and intra-arterial pressure monitoring 1
• Monitor closely for cerebral edema, especially with overly aggressive fluid resuscitation 1

Search for precipitating cause: 4

• Infection is the most common trigger (30-50% of cases), particularly urinary tract infection and pneumonia 4
• Other causes include medication non-compliance, myocardial infarction, stroke, pancreatitis 1, 4
• Failure to identify and treat the underlying cause leads to recurrence 1