What are the differences in management of diabetic ketoacidosis (DKA) between type 1 and type 2 diabetes?

Management of Diabetic Ketoacidosis: Type 1 vs Type 2 Diabetes

The core management principles for DKA are identical regardless of whether the patient has type 1 or type 2 diabetes—both require fluid resuscitation, continuous intravenous insulin, and electrolyte replacement. 1 The key difference lies not in acute DKA treatment itself, but in the diagnostic challenge of distinguishing diabetes type at presentation and the subsequent long-term management after DKA resolution.

Acute DKA Management (Same for Both Types)

The fundamental approach to DKA is uniform across diabetes types:

• Continuous intravenous insulin is the standard of care for critically ill and mentally obtunded patients with DKA, regardless of diabetes type 1
• Fluid resuscitation to restore circulatory volume and tissue perfusion is essential 1
• Electrolyte replacement and correction of acidosis follow the same protocols 1
• Bicarbonate use is generally not recommended as studies show no difference in resolution of acidosis or time to discharge 1

For uncomplicated mild-to-moderate DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management show no significant difference in outcomes compared to IV insulin, and may be safer and more cost-effective 1

Critical Diagnostic Distinction at Presentation

The major challenge is determining diabetes type when patients present with DKA:

In youth with overweight/obesity presenting with DKA:

• Approximately 6% of youth aged 10-19 years with type 2 diabetes present with DKA at onset 1
• Diabetes-associated autoantibodies and ketosis can be present even in patients with features of type 2 diabetes (obesity, acanthosis nigricans) 1
• Check pancreatic autoantibodies while managing the acute DKA to guide subsequent therapy 1

In adults:

• Type 2 diabetes patients can develop DKA under stressful conditions (trauma, surgery, infections), though typically with higher blood glucose levels and milder ketoacidosis 2, 3
• SGLT-2 inhibitor use in type 2 diabetes can cause euglycemic DKA, presenting with lower glucose levels than classic DKA 3

Post-DKA Resolution: Where Management Diverges

Once DKA resolves, management pathways differ dramatically:

Type 1 Diabetes (or Autoantibody-Positive)

• Continue multiple daily insulin injections or insulin pump therapy indefinitely 1
• Discontinue metformin if it was started 1
• Lifelong insulin dependence is required

Type 2 Diabetes (Autoantibody-Negative)

For youth with type 2 diabetes:

• Add metformin after ketosis/ketoacidosis resolution and titrate to 2,000 mg daily 1
• If initially treated with basal insulin and meeting glucose targets, insulin can be tapered over 2-6 weeks by decreasing dose 10-30% every few days 1
• Many patients can be weaned off insulin entirely and managed with metformin plus lifestyle modification 1
• If A1C goals not met on metformin alone, consider adding GLP-1 receptor agonist (approved for youth ≥10 years) or reinitiate insulin 1

For adults with type 2 diabetes:

• Similar approach: transition from IV to subcutaneous insulin requires basal insulin administration 2-4 hours prior to stopping IV insulin to prevent recurrence 1
• Subsequently taper insulin as glucose control improves with oral agents and lifestyle modification 2, 4

Specific Clinical Scenarios

When distinction between type 1 and type 2 is unclear:

• Treat initially with insulin while autoantibody testing is pending 1
• In youth with random glucose ≥250 mg/dL or A1C ≥8.5%, start insulin regardless of suspected type 1

Checkpoint inhibitor-associated diabetes mellitus (CIADM):

• Presents like type 1 diabetes with acute onset polyuria, polydipsia, weight loss, and lethargy 1
• New-onset hyperglycemia without risk factors for type 2 diabetes should raise concern 1
• Treat with insulin immediately; do not delay for antibody results 1
• No immunosuppressive strategies are indicated 1

Common Pitfalls to Avoid

• Do not assume type 2 diabetes cannot present with DKA—it occurs in both types, though more common in type 1 5, 2, 6, 4
• Do not stop IV insulin before administering subcutaneous basal insulin—this causes rebound hyperglycemia and recurrent ketoacidosis 1
• Do not continue insulin indefinitely in type 2 diabetes without attempting to wean—many can be managed without insulin after DKA resolution 1
• Do not overlook precipitating causes—infection (especially UTI and pneumonia) is the most common trigger in 30-50% of cases 2