What is the protocol for managing diabetic ketoacidosis (DKA)?

Diabetic Ketoacidosis (DKA) Management Protocol

The management of diabetic ketoacidosis requires immediate fluid resuscitation with isotonic saline, insulin therapy, electrolyte replacement (particularly potassium), and identification and treatment of precipitating factors. 1

Diagnostic Criteria for DKA

• Blood glucose >250 mg/dL
• Arterial pH <7.3
• Serum bicarbonate <15 mEq/L
• Moderate ketonuria or ketonemia

Initial Assessment and Monitoring

• Obtain immediately:
  • Arterial blood gases
  • Complete blood count with differential
  • Urinalysis
  • Blood glucose
  • Blood urea nitrogen
  • Electrolytes
  • Chemistry profile
  • Creatinine levels
  • Electrocardiogram
• Obtain chest X-ray and cultures as needed to identify infection
• Calculate corrected serum sodium: add 1.6 mEq for each 100 mg/dL glucose >100 mg/dL

Treatment Algorithm for Adults

1. Fluid Therapy

• First hour: Isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr (approximately 1-1.5 L in average adult)
• Subsequent fluid choice:
  • If corrected serum sodium normal/elevated: 0.45% NaCl at 4-14 mL/kg/hr
  • If corrected serum sodium low: 0.9% NaCl at 4-14 mL/kg/hr
• Correct estimated fluid deficits within 24 hours
• Do not exceed osmolality change of 3 mOsm/kg/hr

2. Insulin Therapy

• Regular insulin continuous IV infusion at 0.1 units/kg/hr
• Continue until resolution of DKA (glucose <200 mg/dL, bicarbonate ≥18 mEq/L, venous pH >7.3)
• For mild DKA only: Consider subcutaneous/intramuscular insulin
  • Initial "priming" dose of 0.4-0.6 units/kg (half IV bolus, half SC/IM)
  • Then 0.1 unit/kg/hr SC/IM

3. Potassium Replacement

• Once renal function is assured, add 20-30 mEq/L potassium to IV fluids
• Use 2/3 KCl and 1/3 KPO₄
• Continue until patient can tolerate oral supplementation
• Monitor serum potassium closely as insulin therapy lowers potassium levels

4. Bicarbonate Therapy

• Generally not recommended for pH >7.0
• Consider only if pH <6.9: 50 mmol sodium bicarbonate diluted in 200 mL sterile water, infused at 200 mL/hr

5. Phosphate Replacement

• Routine replacement not supported by evidence
• Consider only for patients with:
  • Cardiac dysfunction
  • Anemia
  • Respiratory depression
  • Serum phosphate <1.0 mg/dL

6. Monitoring During Treatment

• Check blood glucose hourly
• Electrolytes, BUN, creatinine, osmolality, and venous pH every 2-4 hours
• Monitor fluid input/output
• Assess hemodynamic status and mental status frequently

Treatment Algorithm for Pediatric Patients (<20 years)

1. Fluid Therapy

• First hour: Isotonic saline (0.9% NaCl) at 10-20 mL/kg/hr
• Initial reexpansion should not exceed 50 mL/kg over first 4 hours
• Calculate subsequent fluid to replace deficit evenly over 48 hours
• Use 0.9% NaCl at 1.5 times maintenance requirements

2. Insulin Therapy

• Same as adults: 0.1 units/kg/hr continuous IV infusion
• Continue until resolution of DKA

3. Potassium Replacement

• Once renal function is assured, add 20-40 mEq/L potassium to IV fluids
• Use 2/3 KCl and 1/3 KPO₄

4. Monitoring

• More vigilant monitoring for cerebral edema
• Assess neurological status frequently

Transition from IV to Subcutaneous Insulin

• When DKA is resolved (glucose <200 mg/dL, bicarbonate ≥18 mEq/L, pH >7.3):
  • If NPO: Continue IV insulin and supplement with SC regular insulin as needed
  • If eating: Start multiple-dose insulin schedule with combination of short/rapid-acting and intermediate/long-acting insulin
  • Continue IV insulin for 1-2 hours after SC insulin is initiated to prevent rebound hyperglycemia

Common Pitfalls and Caveats

1. Cerebral Edema Risk: Most common in children; avoid rapid fluid administration and excessive osmolality changes
2. Potassium Depletion: Both insulin therapy and correction of acidosis drive potassium intracellularly; monitor closely
3. Bicarbonate Administration: Generally contraindicated except in severe acidosis (pH <6.9)
4. Monitoring Ketosis: β-hydroxybutyrate (β-OHB) is the preferred method; nitroprusside method only measures acetoacetic acid and acetone
5. Abrupt Insulin Discontinuation: Can lead to rebound hyperglycemia; overlap IV and SC insulin during transition

Resolution Criteria

• Blood glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3

This protocol emphasizes the importance of frequent monitoring and adjustment of therapy based on the patient's response, with particular attention to preventing complications such as cerebral edema, which is responsible for most DKA-related deaths in children 2.