What is the recommended treatment protocol for an adult with diabetic ketoacidosis (DKA) presenting with hyperglycemia, ketonemia, metabolic acidosis, and dehydration?

DKA Management Protocol

Initial Assessment and Diagnosis

Confirm DKA by meeting all three criteria: blood glucose >250 mg/dL, venous pH <7.3, and serum bicarbonate <15 mEq/L with moderate ketonuria or ketonemia. 1, 2

Immediate Laboratory Workup

• Draw venous blood gases (arterial not required after initial diagnosis), complete metabolic panel, serum β-hydroxybutyrate (preferred over nitroprusside-based ketone tests), BUN, creatinine, calculated anion gap, urinalysis, CBC with differential, and ECG 3, 1, 2
• Calculate anion gap using [Na+] - ([Cl-] + [HCO3-]); should be >10-12 mEq/L in DKA 1, 2
• Correct serum sodium by adding 1.6 mEq/L for every 100 mg/dL glucose above 100 mg/dL 1, 2
• Obtain bacterial cultures (blood, urine, throat) if infection suspected, as infection is the most common precipitating factor 3, 1, 4

Identify Precipitating Causes

Look specifically for: infection (most common), myocardial infarction, cerebrovascular accident, insulin omission/inadequacy, pancreatitis, SGLT2 inhibitor use, glucocorticoid therapy, or pregnancy 3, 1, 4

Fluid Resuscitation Protocol

Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour) to restore intravascular volume and renal perfusion. 3, 1, 2, 4

After the First Hour

• Calculate corrected serum sodium (add 1.6 mEq/L per 100 mg/dL glucose above 100) 1, 2
• If corrected sodium is normal or elevated: switch to 0.45% NaCl at 4-14 mL/kg/hour 3, 1, 2
• If corrected sodium is low: continue 0.9% NaCl at 4-14 mL/kg/hour 3, 1, 2
• Aim to correct total fluid deficit (typically 6-9 L) within 24 hours while limiting osmolality change to ≤3 mOsm/kg/hour to prevent cerebral edema 3, 1

When Glucose Reaches 250 mg/dL

Switch to 5% dextrose with 0.45-0.75% NaCl while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution, as ketonemia clears more slowly than hyperglycemia 3, 1, 2, 4

Potassium Management

Total body potassium depletion is universal in DKA (3-5 mEq/kg) even when serum levels appear normal or elevated. 3, 1

Critical Potassium Thresholds

• If K+ <3.3 mEq/L: HOLD insulin and replace potassium aggressively at 20-40 mEq/hour until K+ ≥3.3 mEq/L to prevent fatal arrhythmias, cardiac arrest, and respiratory muscle weakness 3, 1, 2
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq/L potassium to IV fluids (2/3 KCl + 1/3 KPO4) once adequate urine output confirmed 3, 1, 2, 4
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor every 2-4 hours, as levels will drop rapidly with insulin therapy 3, 1
• Target serum potassium: 4-5 mEq/L throughout treatment 3, 1, 4

Insulin Therapy

Confirm serum potassium ≥3.3 mEq/L before starting insulin to avoid life-threatening hypokalemia. 1, 2, 4

Standard IV Insulin Protocol (Moderate-Severe DKA or Critically Ill Patients)

• Give IV bolus of 0.1-0.15 units/kg regular insulin (optional but not required) 3, 1
• Start continuous IV regular insulin infusion at 0.1 units/kg/hour 3, 1, 2
• Target glucose decline: 50-75 mg/dL per hour 3, 1, 4
• If glucose does not fall ≥50 mg/dL in first hour despite adequate hydration: double the insulin infusion rate each hour until steady decline achieved 3, 1

Alternative Protocol for Mild-Moderate Uncomplicated DKA

For hemodynamically stable, alert patients: subcutaneous rapid-acting insulin analogs at 0.15 units/kg every 2-3 hours combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin 1

Critical Insulin Management Rules

• Never stop insulin based on glucose levels alone—continue until ALL resolution criteria met 1, 2
• When glucose reaches 250 mg/dL, add dextrose to IV fluids while maintaining insulin infusion 3, 1, 2
• Stopping insulin prematurely is a common cause of recurrent ketoacidosis 3, 1

Monitoring During Treatment

Draw blood every 2-4 hours for serum electrolytes, glucose, BUN, creatinine, calculated osmolality, venous pH, and β-hydroxybutyrate. 3, 1, 2, 4

• Use venous pH (typically 0.03 units lower than arterial) rather than repeated arterial blood gases after initial diagnosis 3, 1, 4
• Calculate anion gap with each draw to track acidosis resolution 1, 2
• β-hydroxybutyrate measurement in blood is the preferred method for monitoring ketosis resolution; nitroprusside-based tests miss the predominant ketone body and may delay appropriate therapy 3, 1

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0, as multiple studies show no difference in resolution time or outcomes, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 3, 1

• Only consider bicarbonate if pH <6.9: give 100 mmol sodium bicarbonate diluted in 400 mL sterile water, infused at 200 mL/hour 1

Resolution Criteria

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 3, 1, 2, 4

Transition to Subcutaneous Insulin

Administer basal subcutaneous insulin (NPH, detemir, glargine, or degludec) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia 3, 1, 2, 4

• Calculate total daily dose based on pre-admission regimen or estimate 0.5-1.0 units/kg/day for newly diagnosed patients 1, 2
• Once patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin 3, 1
• Recent evidence shows adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1

Special Considerations

Euglycemic DKA

• SGLT2 inhibitors are the leading cause of euglycemic DKA (glucose <200-250 mg/dL with ketoacidosis) 1
• Discontinue SGLT2 inhibitors immediately and do not restart until 3-4 days after metabolic stability achieved 1
• Check ketones during illness even if glucose is normal in patients on SGLT2 inhibitors 1

Common Pitfalls to Avoid

• Starting insulin before correcting hypokalemia (K+ <3.3 mEq/L) causes life-threatening arrhythmias 1
• Stopping insulin when glucose falls to 250 mg/dL instead of adding dextrose leads to recurrent ketoacidosis 3, 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 3, 1
• Overly rapid correction of osmolality (>3 mOsm/kg/hour) increases cerebral edema risk 3, 1
• Using nitroprusside-based ketone tests misses β-hydroxybutyrate and delays appropriate therapy 3, 1

Discharge Planning

• Ensure structured discharge plan including DKA recognition, prevention, and sick-day management education 1, 2
• Verify adequate outpatient insulin supply and scheduled follow-up appointments 1, 2
• Identify outpatient diabetes care providers before discharge 3, 1
• Educate on glucose monitoring, insulin administration, and recognition/treatment of hyperglycemia/hypoglycemia 1