What is the treatment approach for a patient with type 2 diabetes (T2D) presenting with diabetic ketoacidosis (DKA)?

Treatment of Diabetic Ketoacidosis in Type 2 Diabetes

Patients with type 2 diabetes presenting with DKA require immediate treatment with continuous intravenous insulin and aggressive fluid resuscitation in an inpatient setting, identical to the management of type 1 DKA. 1

Initial Assessment and Stabilization

Diagnostic confirmation requires:

• Blood glucose >250 mg/dL (though euglycemic DKA can occur, especially with SGLT2 inhibitors) 1
• Arterial pH <7.3 1
• Serum bicarbonate <15 mEq/L 1
• Presence of ketonemia or ketonuria 1

Essential laboratory evaluation includes: plasma glucose, blood urea nitrogen/creatinine, serum ketones, electrolytes with calculated anion gap, osmolality, urinalysis, urine ketones, arterial blood gases, complete blood count with differential, and electrocardiogram. 1 Obtain bacterial cultures (urine, blood, throat) if infection is suspected and initiate appropriate antibiotics immediately. 1

Identify precipitating factors: infection, cerebrovascular accident, alcohol abuse, pancreatitis, myocardial infarction, trauma, drugs (particularly SGLT2 inhibitors which must be discontinued), or insulin discontinuation/inadequacy. 1, 2

Fluid Resuscitation

Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in the average adult) during the first hour. 1 This aggressive initial fluid replacement is critical for restoring tissue perfusion and improving insulin sensitivity. 1

Subsequent fluid choice depends on hydration status, serum electrolyte levels, and urine output. 1 When serum glucose reaches 250 mg/dL, change fluid to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy. 1 Total fluid replacement should aim to correct estimated deficits within 24 hours. 1

Insulin Therapy

For critically ill and mentally obtunded patients with DKA, continuous intravenous insulin is the standard of care. 3, 1 Start with continuous intravenous regular insulin infusion at 0.1 units/kg/hour. 1

If plasma glucose does not fall by 50 mg/dL from initial value in the first hour, check hydration status; if acceptable, double the insulin infusion rate every hour until a steady glucose decline of 50-75 mg/h is achieved. 1

Critical: Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, and anion gap ≤12 mEq/L) regardless of glucose levels. 1 Premature termination of insulin therapy before complete resolution of ketosis is a common cause of recurrent DKA. 1

For mild-to-moderate uncomplicated DKA in alert patients, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective and safer than IV insulin. 3, 1 However, this requires adequate nurse training, frequent bedside testing, and appropriate follow-up. 3

Electrolyte Management

Potassium replacement is critical: Despite potentially normal or elevated initial serum levels due to acidosis, total body potassium depletion is universal in DKA. 1, 4

If K+ <3.3 mEq/L, delay insulin therapy and aggressively replace potassium until levels reach ≥3.3 mEq/L to prevent life-threatening arrhythmias and respiratory muscle weakness. 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 is confirmed. 1, 4 Target serum potassium of 4-5 mEq/L throughout treatment. 1

If K+ >5.5 mEq/L, withhold potassium initially but monitor closely, as levels will drop rapidly with insulin therapy. 1

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

Monitoring During Treatment

Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH. 1, 4 Follow venous pH (typically 0.03 units lower than arterial pH) and anion gap to monitor resolution of acidosis. 1

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA, as the nitroprusside method only measures acetoacetic acid and acetone. 1

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

Resolution Criteria

DKA is resolved when ALL of the following are met:

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

Transition to Subcutaneous Insulin

Once DKA is resolved, administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia. 1 This overlap period is essential. 1

When the patient is able to eat, start a multiple-dose schedule using a combination of short/rapid-acting and intermediate/long-acting insulin. 1 Many patients with type 2 diabetes can eventually be weaned from insulin therapy and subsequently managed with metformin and lifestyle modification. 3

Common Pitfalls to Avoid

Interruption of insulin infusion when glucose levels fall is a common cause of persistent or worsening ketoacidosis. 1 The key error is stopping insulin before ketosis resolves—continue insulin and add dextrose instead. 1

Failure to add dextrose when glucose falls below 250 mg/dL while continuing insulin therapy leads to hypoglycemia. 1

Inadequate monitoring and replacement of electrolytes, particularly potassium, is a leading cause of mortality in DKA. 1

Overly rapid correction of osmolality increases the risk of cerebral edema, particularly in children. 1

Discharge Planning

Before discharge, ensure:

• Identification of the health care provider who will provide diabetes care after discharge 3
• Patient understanding of diabetes diagnosis, self-monitoring of blood glucose, home blood glucose goals, and when to call the provider 3
• Education on recognition, treatment, and prevention of hyperglycemia and hypoglycemia 3
• Appropriate durable medical equipment, medications, supplies (blood glucose test strips), and prescriptions 3
• Scheduled outpatient medical follow-up appointment prior to discharge 3

Discharge summaries should be transmitted to the primary care provider as soon as possible after discharge. 3