How to manage a patient with Diabetic Ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, and aggressively replace potassium to maintain levels between 4-5 mEq/L throughout treatment. 1, 2, 3

Initial Assessment and Diagnosis

Diagnostic Criteria:

• Blood glucose >250 mg/dL 4, 2, 3
• Arterial pH <7.3 4, 2, 3
• Serum bicarbonate <15-18 mEq/L 4, 2, 3
• Positive serum/urine ketones 4, 2, 3

Immediate Laboratory Workup:

• Obtain plasma glucose, electrolytes with calculated anion gap, BUN/creatinine, serum ketones (preferably β-hydroxybutyrate), osmolality, arterial blood gases, complete blood count, urinalysis, urine ketones, and ECG 4, 1, 2, 3
• Obtain bacterial cultures (blood, urine, throat) and chest X-ray if infection is suspected 4, 1, 2
• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method, which only measures acetoacetic acid and acetone 2, 3

Identify Precipitating Factors:

• Infection (most common), myocardial infarction, stroke, pancreatitis, trauma, insulin omission/inadequacy, SGLT2 inhibitor use, or new diabetes diagnosis 4, 3, 5

Fluid Resuscitation Protocol

First Hour:

• Administer isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour (approximately 1-1.5 L in average adult) 4, 1, 2, 3
• This initial aggressive fluid replacement is critical for restoring tissue perfusion and improving insulin sensitivity 3

Subsequent Fluid Management:

• Use 0.45% NaCl at 4-14 ml/kg/hour if corrected serum sodium is normal or elevated 4
• Use 0.9% NaCl at similar rate if corrected serum sodium is low 4
• Correct serum sodium for hyperglycemia: add 1.6 mEq to sodium value for each 100 mg/dL glucose above 100 mg/dL 4
• When glucose reaches 200-250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin to prevent hypoglycemia and ensure complete ketoacidosis resolution 1, 2, 3
• Total fluid replacement should correct estimated deficits within 24 hours 4, 2
• Change in serum osmolality should not exceed 3 mOsm/kg H2O per hour to prevent cerebral edema 4

Potassium Management (Critical)

This is the most dangerous electrolyte abnormality in DKA and requires meticulous attention:

If K+ <3.3 mEq/L:

• DO NOT START INSULIN - this is an absolute contraindication 1, 3
• Delay insulin therapy and aggressively replace potassium until K+ ≥3.3 mEq/L to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness 1, 3
• Add 20-40 mEq/L potassium to IV fluids once adequate urine output is confirmed 1

If K+ 3.3-5.5 mEq/L:

• Add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl or potassium-acetate and 1/3 KPO4) once renal function is assured 4, 1, 2, 3
• Start insulin therapy 1, 3

If K+ >5.5 mEq/L:

• Withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy 3

Critical Concept: Total body potassium depletion in DKA averages 3-5 mEq/kg body weight, and insulin therapy will unmask this depletion by driving potassium intracellularly 3. Despite total body depletion being universal, only a small percentage present with hypokalemia, making this a high-risk scenario 3. Target serum potassium of 4-5 mEq/L throughout treatment 2, 3.

Insulin Therapy Protocol

Standard IV Insulin Regimen (for moderate-severe DKA or critically ill patients):

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour (an initial bolus of 0.1 units/kg is optional) 1, 2, 3
• Target glucose decline of 50-75 mg/dL per hour 1, 2, 3
• If glucose does not fall by 50 mg/dL in first hour, verify adequate hydration, then double insulin infusion rate hourly until achieving steady decline of 50-75 mg/dL/hour 1, 2, 3
• When glucose reaches 250 mg/dL, decrease insulin infusion to 0.05-0.1 units/kg/hour AND add dextrose to IV fluids 1, 2
• Continue insulin infusion until complete resolution of ketoacidosis regardless of glucose levels - this is critical 1, 2, 3

Alternative Approach for Mild-Moderate Uncomplicated DKA:

• For hemodynamically stable, alert patients with mild-moderate DKA, subcutaneous rapid-acting insulin analogs (0.15 units/kg every 2-3 hours) combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 4, 1, 3, 6
• This requires adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 3

Monitoring Protocol

Frequent Laboratory Monitoring:

• Check blood glucose every 1-2 hours 2
• Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH 4, 1, 2, 3
• Venous pH is typically 0.03 units lower than arterial pH and is adequate for monitoring 2, 3
• Follow anion gap to monitor resolution of acidosis 2, 3
• Check potassium every 2-4 hours during active treatment 3

Bicarbonate Administration

Bicarbonate is NOT recommended for pH >6.9-7.0 4, 1, 2, 3. Multiple studies show no difference in resolution of acidosis or time to discharge with bicarbonate use, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 4, 1, 3, 6. Consider bicarbonate only if pH <6.9 or in peri-intubation period to prevent hemodynamic collapse 6.

DKA Resolution Criteria

All of the following must be met:

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

Target glucose between 150-200 mg/dL until all resolution parameters are met 3.

Transition to Subcutaneous Insulin

This is the most common error leading to DKA recurrence:

• Administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion 4, 1, 2, 3
• This overlap period is essential to prevent recurrence of ketoacidosis and rebound hyperglycemia 4, 1, 2, 3
• Continue IV insulin for 1-2 hours after subcutaneous insulin is given 1
• Recent evidence shows adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 3
• Start multiple-dose regimen with combination of short/rapid-acting and intermediate/long-acting insulin once patient can eat 1, 2, 3

Special Considerations and Pitfalls

Cerebral Edema Prevention:

• Occurs more commonly in children and adolescents than adults 3, 7
• Avoid overly rapid correction of osmolality (should not exceed 3 mOsm/kg H2O per hour) 4
• Monitor closely for altered mental status, headache, or neurological deterioration 3

SGLT2 Inhibitors:

• Must be discontinued immediately and not restarted until 3-4 days after metabolic stability is achieved 4, 3
• Can precipitate euglycemic DKA 4, 3

Phosphate Replacement:

• Routine phosphate replacement has not shown clinical benefit 2
• Consider careful replacement in patients with cardiac dysfunction, anemia, respiratory depression, or serum phosphate <1.0 mg/dL 2

Common Errors to Avoid:

• Stopping IV insulin without prior basal insulin administration (most common error) 1, 3
• Starting insulin when K+ <3.3 mEq/L 1, 3
• Interrupting insulin infusion when glucose falls without adding dextrose 2, 3
• Premature termination of insulin therapy before complete resolution of ketosis 2, 3
• Inadequate potassium monitoring and replacement 3

Treatment of Underlying Precipitating Cause

Concurrent treatment is essential:

• Administer appropriate antibiotics if infection is suspected 4, 1, 2
• Manage myocardial infarction, stroke, pancreatitis, or other precipitating factors 4, 3
• Treatment of underlying cause must occur simultaneously with correction of metabolic derangement 3

Discharge Planning

Structured discharge plan should include:

• Appropriate insulin regimen with attention to medication access and affordability 3
• Patient education on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia, and sick day management 4, 3
• Identification of outpatient diabetes care providers 3
• Scheduled follow-up appointments prior to discharge 3
• Education on DKA prevention to reduce recurrence 3, 5