What is the primary treatment goal and guideline for a patient with diabetic ketoacidosis (DKA)?

Diabetic Ketoacidosis Treatment Guidelines

Diagnostic Criteria

DKA is diagnosed by blood glucose >250 mg/dL (though euglycemic DKA exists), arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria. 1, 2

• Obtain plasma glucose, blood urea nitrogen, creatinine, serum ketones, electrolytes with calculated anion gap, osmolality, urinalysis, arterial blood gases, complete blood count with differential, and electrocardiogram immediately 1, 2, 3
• Direct measurement of β-hydroxybutyrate in blood is preferred over nitroprusside method, which only detects acetoacetic acid and acetone 2, 3
• Obtain bacterial cultures (urine, blood, throat) and administer appropriate antibiotics if infection is suspected 1, 2

Initial Fluid Resuscitation

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

• After initial resuscitation, switch to 0.45% NaCl at 4-14 mL/kg/hour if corrected serum sodium is normal or elevated; continue 0.9% NaCl if corrected sodium is low 1
• When serum glucose reaches 200-250 mg/dL, change fluid to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution 1, 2, 3
• Correct estimated fluid deficits within 24 hours, ensuring serum osmolality changes do not exceed 3 mOsm/kg/hour 3

Insulin Therapy

Start continuous intravenous regular insulin infusion at 0.1 units/kg/hour without an initial bolus for moderate-to-severe DKA or critically ill/mentally obtunded patients. 2, 4

• If plasma glucose does not fall by 50 mg/dL in the first hour, check hydration status; if adequate, double the insulin infusion rate every hour until steady glucose decline of 50-75 mg/hour is achieved 1, 2
• Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1, 2
• Target glucose between 150-200 mg/dL during treatment; do not stop insulin when glucose normalizes 2, 4

Alternative for Mild-Moderate Uncomplicated DKA

For hemodynamically stable, alert patients with mild-to-moderate uncomplicated DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective, safer, and more cost-effective than IV insulin. 2, 4

Critical Potassium Management

Total body potassium depletion averages 3-5 mEq/kg despite potentially normal or elevated initial levels due to acidosis; insulin therapy will unmask this depletion by driving potassium intracellularly. 2, 3

• If initial potassium <3.3 mEq/L, delay insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias, cardiac arrest, and respiratory muscle weakness 2, 4
• Once adequate urine output is confirmed and potassium is 3.3-5.5 mEq/L, add 20-30 mEq potassium per liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) 1, 2, 3
• If potassium >5.5 mEq/L, withhold potassium initially but monitor closely every 2-4 hours, as levels will drop rapidly with insulin therapy 2
• Target serum potassium of 4-5 mEq/L throughout treatment 2, 3

Bicarbonate Therapy

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0, as multiple studies show no difference in resolution of acidosis or time to discharge, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 2, 3, 4

• For adult patients with pH <6.9, administer 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/hour 3
• For pH 6.9-7.0, administer 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/hour 3

Monitoring During Treatment

Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH (typically 0.03 units lower than arterial pH). 1, 2, 3

• Monitor blood glucose every 1-2 hours during active treatment 4
• Continuous cardiac monitoring is crucial to detect arrhythmias early from electrolyte shifts 3, 4
• Follow venous pH and anion gap to monitor resolution of acidosis 1, 3

Resolution Criteria

DKA is resolved when glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L. 2, 3, 4

Transition to Subcutaneous Insulin

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

• Once DKA is resolved and patient can eat, transition to multiple-dose regimen using combination of short/rapid-acting and intermediate/long-acting insulin 2, 3
• For newly diagnosed patients, initiate approximately 0.5-1.0 units/kg/day 3
• Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 2, 4

Identifying and Treating Precipitating Causes

Search for and treat underlying triggers: infection, myocardial infarction, stroke, pancreatitis, trauma, insulin omission, or medication-related causes. 1, 2, 3

• SGLT2 inhibitors can cause euglycemic DKA and must be discontinued immediately; do not restart until 3-4 days after acute illness resolves to prevent recurrence 2, 4
• Obtain chest X-ray, cultures, troponin, and other tests as clinically indicated 1

Common Pitfalls to Avoid

• Premature termination of insulin therapy before complete resolution of ketosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) leads to recurrence of DKA 2
• Interrupting insulin infusion when glucose falls below 250 mg/dL without adding dextrose-containing fluids causes persistent or worsening ketoacidosis 2, 4
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA 2
• Overly rapid correction of osmolality increases risk of cerebral edema, particularly in children 2, 3

Discharge Planning

• Identify outpatient diabetes care provider before discharge 2, 3
• Educate patients on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia, and sick-day management 2, 3, 4
• Schedule follow-up appointments within 1-2 weeks prior to discharge 2, 4