What is the best approach to manage a patient with diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis

Initial Assessment and Diagnosis

Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour immediately, as this is the cornerstone of DKA management and improves insulin sensitivity. 1

Diagnostic Criteria

• Confirm DKA with: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1
• Obtain stat labs: plasma glucose, arterial or venous blood gases, complete metabolic panel with calculated anion gap, serum ketones (preferably β-hydroxybutyrate), osmolality, complete blood count, and electrocardiogram 1, 2
• Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as nitroprusside methods miss this primary ketone 3

Identify Precipitating Factors

• Immediately evaluate for infection (obtain cultures if suspected), myocardial infarction, stroke, pancreatitis, trauma, or insulin omission 1
• Discontinue SGLT2 inhibitors immediately if the patient is taking them, as these can precipitate euglycemic DKA 1

Fluid Resuscitation Protocol

• Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the first hour for average adults) to restore intravascular volume and renal perfusion 1, 2
• When serum glucose reaches 250 mg/dL, switch to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion—this is critical to prevent hypoglycemia and ensure complete ketoacidosis resolution 1
• Adjust subsequent fluid rate based on hydration status, serum sodium, and urine output 2

Insulin Therapy

For Moderate-to-Severe DKA or Critically Ill Patients

• Start continuous IV regular insulin infusion at 0.1 units/kg/hour WITHOUT an initial bolus for intubated or critically ill patients 2
• Target a glucose decline of 50-75 mg/dL per hour 1
• If glucose does not fall by 50 mg/dL in the first hour, check hydration status; if adequate, double the insulin infusion rate hourly until steady decline achieved 1

For Mild-to-Moderate Uncomplicated DKA

• For hemodynamically stable, alert patients with mild-moderate DKA, 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
• This approach requires adequate fluid replacement, frequent point-of-care glucose monitoring, and treatment of concurrent infections 1

Critical Insulin Management Rule

• Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels—never stop insulin just because glucose normalizes 1, 2
• When glucose falls below 250 mg/dL, add dextrose to IV fluids and continue insulin to clear ketones 1

Potassium Management (Critical for Preventing Mortality)

Do NOT start insulin if serum potassium is <3.3 mEq/L—aggressively replace potassium first to prevent life-threatening cardiac arrhythmias and respiratory muscle weakness. 1, 2

Potassium Replacement Protocol

• If K+ <3.3 mEq/L: Hold insulin, give 20-40 mEq/hour potassium until K+ ≥3.3 mEq/L 1
• If K+ 3.3-5.5 mEq/L: Add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed 1, 2
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely every 2 hours, as levels will drop rapidly with insulin therapy 1
• Target serum potassium of 4-5 mEq/L throughout treatment 1, 2
• Total body potassium depletion averages 3-5 mEq/kg body weight in DKA, requiring massive repletion 1

Bicarbonate Administration

Do NOT give bicarbonate for pH >6.9-7.0, as multiple studies show no benefit in resolution time or outcomes, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 1

• Bicarbonate can be considered only if pH <6.9, particularly pre- and post-intubation to prevent hemodynamic collapse 4

Monitoring Protocol

• Draw blood every 2-4 hours for: serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH (venous pH is typically 0.03 units lower than arterial pH) 3, 1, 2
• Monitor potassium levels closely every 2 hours during active treatment, as insulin drives potassium intracellularly, unmasking total body depletion 1
• Follow anion gap and β-hydroxybutyrate to monitor resolution of acidosis 3, 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, and anion gap ≤12 mEq/L. 1, 2

• Target glucose between 150-200 mg/dL until DKA resolution parameters are met 1
• Ketonemia typically takes longer to clear than hyperglycemia 3

Transition to Subcutaneous Insulin

Administer basal insulin (glargine or detemir) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia—this overlap period is essential. 1, 2

• Once DKA is resolved and patient can eat, start multiple-dose schedule using combination of short/rapid-acting and intermediate/long-acting insulin at approximately 0.5-1.0 units/kg/day for newly diagnosed patients 1
• If patient remains NPO after DKA resolution (e.g., intubated), continue IV insulin and supplement with subcutaneous regular insulin every 4 hours as needed 2
• Recent evidence shows adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis leads to recurrence of DKA 3, 1
• Stopping IV insulin without prior administration of basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis 1
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 1
• Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy 1
• Overly rapid correction of osmolality increases risk of cerebral edema, particularly in children and adolescents 1

Special Considerations for Intubated/ICU Patients

• For intubated patients with impending respiratory failure, use intubation and mechanical ventilation with careful monitoring of acid-base and fluid status—avoid BiPAP due to aspiration risk 4
• Check for precipitating factors requiring immediate intervention: sepsis, myocardial infarction, stroke, aspiration pneumonia, or pancreatitis 2
• Continuous IV regular insulin at 0.1 units/kg/hour remains the standard of care for critically ill and mentally obtunded patients 1, 2

Discharge Planning

• Identify outpatient diabetes care providers before discharge 1
• Educate patients on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia, and when to call healthcare professional 1
• Ensure appropriate insulin regimen is prescribed with attention to medication access and affordability 1
• Do not restart SGLT2 inhibitors until 3-4 days after metabolic stability is achieved 1