What are the clinical management steps for diabetic ketoacidosis?

Clinical Management of Diabetic Ketoacidosis

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour in the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour once serum potassium is ≥3.3 mEq/L, while simultaneously identifying and treating any precipitating cause. 1, 2

Initial Assessment and Diagnosis

Obtain stat laboratory studies to confirm DKA and guide management 1, 2:

• Diagnostic criteria require all three: blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1
• Draw plasma glucose, serum ketones (β-hydroxybutyrate preferred), electrolytes with calculated anion gap, arterial or venous blood gas, BUN, creatinine, osmolality, complete blood count, urinalysis with urine ketones, and ECG 1, 2
• Critical pitfall: Use β-hydroxybutyrate measurement in blood rather than nitroprusside-based tests, which only detect acetoacetate and acetone, missing the predominant ketone body 1, 3

Identify precipitating factors immediately 1, 2:

• Obtain bacterial cultures (urine, blood, throat) if infection is suspected—infection is the most common DKA trigger 1, 2
• Consider myocardial infarction, cerebrovascular accident, pancreatitis, trauma, insulin omission, or SGLT2 inhibitor use 1
• Discontinue SGLT2 inhibitors immediately if present; do not restart until 3-4 days after metabolic stability 1, 2

Fluid Resuscitation Protocol

First hour: Administer 0.9% normal saline at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) to restore intravascular volume and improve insulin sensitivity 1, 3, 2

After the first hour: Adjust based on corrected serum sodium (add 1.6 mEq/L for each 100 mg/dL glucose above 100 mg/dL) 1:

• If corrected sodium is normal or elevated: switch to 0.45% NaCl at 4-14 mL/kg/hour 1
• If corrected sodium is low: continue 0.9% NaCl at 4-14 mL/kg/hour 1, 2

When glucose reaches 250 mg/dL: Change to 5% dextrose with 0.45-0.75% NaCl while continuing insulin infusion to prevent hypoglycemia and ensure complete ketoacidosis resolution 1, 3, 2

Critical Potassium Management

This is the most dangerous electrolyte abnormality—total body potassium depletion averages 3-5 mEq/kg despite initial serum levels. 1

If K+ <3.3 mEq/L: 1, 3, 2

• Do NOT start insulin—this can cause fatal cardiac arrhythmias
• Continue isotonic saline but hold insulin
• Confirm adequate urine output
• Aggressively replace potassium with 20-40 mEq/L in IV fluids until K+ ≥3.3 mEq/L

If K+ 3.3-5.5 mEq/L: 1, 3

• Add 20-30 mEq potassium per liter of IV fluid (2/3 KCl and 1/3 KPO₄)
• Confirm adequate urine output before starting replacement

If K+ >5.5 mEq/L: 1

• Withhold potassium initially
• Monitor every 2-4 hours as levels will drop rapidly with insulin therapy

Target serum potassium: 4-5 mEq/L throughout treatment 1, 3

Insulin Therapy Protocol

Once K+ ≥3.3 mEq/L confirmed: 1, 2

• Give IV bolus of 0.1 units/kg regular insulin 1, 2
• Start continuous infusion at 0.1 units/kg/hour regular insulin 1, 3, 2
• Target glucose decline: 50-75 mg/dL per hour 1, 3, 2

If glucose does not fall by 50 mg/dL in the first hour: 1

• Check hydration status
• If acceptable, double the insulin infusion rate every hour until steady decline achieved

Critical principle: Continue insulin infusion until resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1, 3

Common pitfall: Stopping insulin when glucose reaches 250 mg/dL leads to recurrent ketoacidosis—instead add dextrose to IV fluids and continue insulin 1

Alternative Approach for Mild-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

However, continuous IV insulin remains the standard of care for moderate-to-severe DKA or critically ill/mentally obtunded patients 1

Monitoring During Treatment

Draw blood every 2-4 hours for 1, 3, 2:

• Serum electrolytes, glucose, BUN, creatinine, osmolality, and venous pH (arterial gases generally unnecessary)
• Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor acidosis resolution 1
• Use β-hydroxybutyrate measurements for monitoring ketosis resolution—reduction in blood β-OHB is the most accurate marker of successful treatment 1, 3

Resolution Criteria

DKA is resolved when ALL of the following are met: 1, 3, 2

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

Target glucose between 150-200 mg/dL until these resolution parameters are met 1

Bicarbonate Administration

Bicarbonate is NOT recommended for DKA patients with pH >6.9-7.0 1

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 1

Transition to Subcutaneous Insulin

Once DKA is resolved: 1, 3, 2

• Administer basal insulin (glargine, detemir, or NPH) 2-4 hours BEFORE stopping IV insulin infusion—this prevents recurrence of ketoacidosis and rebound hyperglycemia
• Estimate total daily insulin requirement at 0.3-0.4 units/kg/day (0.5-1.0 units/kg/day for newly diagnosed patients) 1, 2
• Give half as basal insulin and half as prandial coverage with rapid-acting insulin 1, 2

Critical pitfall: Stopping IV insulin without prior administration of basal subcutaneous insulin causes rebound hyperglycemia and ketoacidosis 1

Recent evidence shows adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1

Treatment of Precipitating Causes

Administer appropriate antibiotics if infection is confirmed 1, 2

Treat concurrent conditions (myocardial infarction, stroke, pancreatitis) simultaneously with DKA management 1

Special Consideration: Euglycemic DKA

SGLT2 inhibitors are the leading contemporary cause of euglycemic DKA (glucose <200-250 mg/dL with ketoacidosis) 1

• Incidence: 0.6-4.9 events per 1,000 patient-years with relative risk of 2.46 versus placebo 1
• Check urine or blood ketones during illness even if glucose is normal in patients on SGLT2 inhibitors 1
• Avoid prolonged fasting, very-low-carbohydrate diets, and excessive alcohol while taking SGLT2 inhibitors 1

Discharge Planning

Before discharge, ensure 1, 3:

• Identification of outpatient diabetes care providers
• Education on glucose monitoring, insulin administration, recognition and treatment of hyperglycemia/hypoglycemia
• Appropriate insulin regimen prescribed with attention to medication access and affordability
• Understanding of sick-day management: never stop basal insulin even when oral intake is limited 1
• Instructions to measure ketones when glucose exceeds 200 mg/dL or during any illness 1