What are the initial management steps for diabetic ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/h during the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour once potassium is confirmed >3.3 mEq/L, while aggressively monitoring and replacing electrolytes. 1, 2, 3

Immediate Diagnostic Workup

Upon presentation, obtain the following laboratory studies immediately 2, 3:

• Plasma glucose, blood urea nitrogen, creatinine, serum ketones (preferably β-hydroxybutyrate, not nitroprusside method which only measures acetoacetic acid and acetone) 3
• Electrolytes with calculated anion gap and osmolality 1, 2
• Arterial blood gases (though venous pH is adequate for ongoing monitoring, typically 0.03 units lower than arterial) 2, 3
• Complete blood count with differential, urinalysis, electrocardiogram 1, 2
• Bacterial cultures (urine, blood, throat) if infection is suspected 1, 2
• Correct serum sodium for hyperglycemia: add 1.6 mEq to sodium value for each 100 mg/dL glucose above 100 mg/dL 1, 3

Diagnostic criteria for DKA: Blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and moderate ketonuria or ketonemia 1, 2

Fluid Resuscitation Protocol

First Hour

• Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/h (approximately 1-1.5 liters in average adult) to restore circulatory volume and renal perfusion 1, 2
• Some guidelines now recommend balanced electrolyte solutions rather than 0.9% saline to reduce risk of hyperchloremic acidosis 2

Subsequent Fluid Management

After the initial hour, adjust based on corrected serum sodium 1:

• If corrected sodium is normal or elevated: Use 0.45% NaCl at 4-14 mL/kg/h 1
• If corrected sodium is low: Continue 0.9% NaCl at similar rate 1
• Target: Correct estimated deficits within 24 hours, ensuring serum osmolality change does not exceed 3 mOsm/kg/h 4, 2

Typical total body deficits in DKA: Water 6 liters (100 mL/kg), sodium 7-10 mEq/kg, potassium 3-5 mEq/kg, phosphate 5-7 mmol/kg 1

Insulin Therapy

Critical Pre-Insulin Check

NEVER start insulin before excluding hypokalemia - if potassium <3.3 mEq/L, delay insulin and replace potassium first to avoid life-threatening arrhythmias, cardiac arrest, and respiratory muscle weakness 2, 3

Standard IV Insulin Protocol

• Continuous IV regular insulin at 0.1 units/kg/hour without initial bolus (current standard of care for critically ill patients) 2, 3
• Alternative: Some guidelines suggest 0.15 U/kg IV bolus followed by 0.1 U/kg/h infusion 1

Insulin Adjustment

• If glucose does not fall by 50 mg/dL in first hour: Check hydration status; if adequate, double insulin infusion every hour until achieving steady decline of 50-75 mg/h 4, 2, 3
• When glucose reaches 250-300 mg/dL: Add dextrose to IV fluids while continuing insulin at reduced rate (target glucose 250-300 mg/dL until acidosis resolves) 4

Alternative for Mild DKA

• Subcutaneous rapid-acting insulin analogs may be used in emergency department or step-down units for uncomplicated mild DKA, potentially safer and more cost-effective than IV insulin 2
• Dose: 0.15 U/kg every 2-3 hours until metabolic acidosis resolves 5

Electrolyte Management

Potassium Replacement (Critical)

Total body potassium deficits are common despite potentially normal or elevated initial levels due to acidosis 2:

• Once potassium falls below 5.5 mEq/L (assuming adequate urine output): Add 20-40 mEq/L potassium to each liter of IV fluid 4, 2, 3
• Composition: 2/3 KCl and 1/3 KPO4 1, 2
• Target: Maintain serum potassium at 4-5 mEq/L 2, 3

Bicarbonate Therapy (Generally NOT Recommended)

• Do NOT administer bicarbonate if pH >7.0 - studies show no beneficial effects on clinical outcomes 2, 3
• Only if pH <6.9: Consider 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h 2
• If pH 6.9-7.0: Consider 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/h 2

Phosphate Replacement

• Generally NOT routinely recommended - studies fail to show beneficial effects on clinical outcomes 2
• Consider only if: Cardiac dysfunction, anemia, respiratory depression, or serum phosphate <1.0 mg/dL (20-30 mEq/L potassium phosphate) 4, 2

Monitoring Protocol

Frequency

• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 4, 2, 3
• Continuous cardiac monitoring in severe DKA to detect arrhythmias early 2
• Monitor fluid input/output, hemodynamic parameters, clinical examination 4, 2

What to Monitor

• Venous pH and anion gap adequately monitor resolution of acidosis; repeat arterial blood gases generally unnecessary 2, 3
• Watch for cerebral edema (rare but fatal, 0.7-1.0% in children): lethargy, behavioral changes, seizures, incontinence, pupillary changes, bradycardia, respiratory arrest 4, 2

Resolution Criteria

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

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

Transition to Subcutaneous Insulin

Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 4, 2, 3

• For newly diagnosed patients: Initiate multidose regimen at approximately 0.5-1.0 units/kg/day using combination of short/rapid-acting and intermediate/long-acting insulin 2
• Overlap is essential - never stop IV insulin without prior subcutaneous basal insulin administration 2, 3

Identification and Treatment of Precipitating Causes

Search for and treat underlying triggers 2, 3, 6:

• Infection (most common, 30-50% of cases): Obtain cultures and administer appropriate antibiotics if suspected 1, 2
• Myocardial infarction or stroke 2, 3
• Medication non-compliance or insulin omission 6, 7
• SGLT2 inhibitors: Can cause euglycemic DKA - discontinue 3-4 days before surgery 2, 3
• Other: Trauma, pancreatitis, new-onset diabetes 1, 6

Critical Pitfalls to Avoid

• Never start insulin with potassium <3.3 mEq/L - will precipitate life-threatening hypokalemia 2, 3
• Avoid overly rapid correction of hyperglycemia and osmolality - increases cerebral edema risk, especially in children 2
• Do not use sliding scale insulin alone in critically ill patients - continuous IV insulin is standard of care 4
• Never stop IV insulin without prior subcutaneous basal insulin (2-4 hour overlap required) 2, 3
• Do not routinely give bicarbonate unless pH <6.9 - no outcome benefit 2, 3

Discharge Planning

• Structured discharge plan tailored to individual to reduce readmission rates 4, 2, 3
• Patient education: Recognition and prevention of DKA, insulin adjustment during illness, glucose and ketone monitoring, medication compliance 2, 3, 8
• Appropriate insulin regimen: Multiple daily injections or pump therapy as indicated 3