What is euglycemic diabetic ketoacidosis caused by empagliflozin?

Euglycemic Diabetic Ketoacidosis (euDKA) Caused by Empagliflozin

Euglycemic diabetic ketoacidosis (euDKA) caused by empagliflozin is a rare but life-threatening metabolic emergency characterized by severe ketoacidosis and acidemia (pH <7.35) with relatively normal blood glucose levels (<250 mg/dL), occurring due to SGLT2 inhibitor-induced alterations in glucose and ketone metabolism.

Mechanism of euDKA with Empagliflozin

Empagliflozin causes euDKA through several interconnected mechanisms:

• Increased urinary glucose excretion lowers blood glucose without suppressing ketone production, masking the typical hyperglycemic warning signs of DKA 1
• Reduced insulin secretion occurs as glucose levels drop, promoting lipolysis and ketogenesis
• Glucagon elevation is stimulated by lower glucose levels, further driving ketone body production
• Direct renal effects where SGLT2 inhibition reduces renal ketone clearance while simultaneously lowering glucose reabsorption 2

The dangerous aspect is that patients develop severe metabolic acidosis with high anion gap and significant ketonemia (β-hydroxybutyrate typically >3 mmol/L) while glucose remains deceptively normal or only mildly elevated, leading to delayed recognition and treatment 3.

Clinical Presentation and Risk Factors

High-Risk Scenarios for euDKA:

• Insulin deficiency states: Type 1 diabetes, latent autoimmune diabetes in adults (LADA), or advanced type 2 diabetes with β-cell failure 1
• Acute illness: Infections (particularly influenza), sepsis, or critical illness 3, 4
• Reduced carbohydrate intake: Ketogenic diets, prolonged fasting, or poor oral intake 3
• Surgical procedures: Perioperative period with fasting requirements 1
• Cancer treatment: Chemotherapy and immunotherapy (particularly pembrolizumab) causing anorexia, weight loss, and metabolic stress 4, 5
• Pregnancy and pancreatitis: Though less common with empagliflozin use 6

Timing of Onset:

EuDKA can occur as early as 48-72 hours after empagliflozin initiation 3, though most cases occur after prolonged exposure. The rapid onset cases are particularly dangerous as clinicians may not suspect SGLT2 inhibitor involvement.

Diagnostic Features

Laboratory Findings:

• **Arterial pH <7.35** with high anion gap metabolic acidosis (anion gap typically >20)
• Serum bicarbonate <18 mmol/L (often severely depressed, e.g., 5 mmol/L) 3
• β-hydroxybutyrate >3 mmol/L (often >7 mmol/L in severe cases)
• Blood glucose <250 mg/dL (may be 150-250 mg/dL range)
• Positive urine or serum ketones

Critical Pitfall:

The normal or near-normal glucose levels cause delayed diagnosis because clinicians don't suspect DKA. Always check ketones and arterial blood gas in patients on SGLT2 inhibitors presenting with nausea, vomiting, malaise, or unexplained illness, regardless of glucose level 7.

Management Algorithm

Immediate Actions:

1. Discontinue empagliflozin immediately upon suspicion or diagnosis 1, 3
2. Aggressive IV fluid resuscitation with normal saline
3. Insulin infusion (typically 0.1 units/kg/hour), though insulin requirements are often surprisingly low compared to hyperglycemic DKA 3
4. Add dextrose-containing fluids early (when glucose <250 mg/dL) to prevent hypoglycemia while continuing insulin to suppress ketogenesis
5. Electrolyte monitoring and repletion, particularly potassium
6. ICU-level monitoring for severe cases (pH <7.1, altered mental status, hemodynamic instability) 4

Key Management Difference from Hyperglycemic DKA:

Insulin requirements are typically much lower than traditional DKA (total insulin may be only 10-15 units over the entire treatment course) 3. This should prompt reassessment of diabetes phenotype—preserved C-peptide with low insulin needs suggests type 2 diabetes rather than type 1, despite ketoacidosis presentation.

Prevention Strategies

Mandatory Sick-Day Planning 1:

Discontinue empagliflozin during:

• Any acute illness with reduced oral intake
• Planned surgical procedures (stop 3-4 days before surgery)
• Critical illness or prolonged fasting
• Initiation of ketogenic or very low-carbohydrate diets

Patient Education Must Include:

• Recognition of early symptoms (nausea, vomiting, abdominal pain, fatigue, confusion)
• Stop empagliflozin immediately when unable to eat or drink normally
• Seek medical attention for persistent symptoms even if glucose is normal
• Avoid combining with ketogenic diets without close monitoring

High-Risk Populations Requiring Extra Caution:

• Cancer patients receiving chemotherapy or immunotherapy with high risk of anorexia and infections 4, 5
• Patients with unexpectedly low insulin requirements suggesting possible LADA or evolving type 1 diabetes 3
• Those with history of pancreatitis or recurrent infections

Special Considerations

Obscured Presentations:

EuDKA can be masked by concurrent metabolic alkalosis from vomiting, making the acidosis less apparent on initial labs 7. Always calculate the anion gap and check ketones even when pH appears near-normal.

Non-Diabetic Patients:

While rare, euDKA has been reported in non-diabetic patients taking SGLT2 inhibitors for heart failure 8, emphasizing that this complication is not limited to diabetic populations.

Recurrence Risk:

Do not restart empagliflozin after an episode of euDKA 3. The risk of recurrent metabolic decompensation is substantial, and alternative diabetes or heart failure medications should be used.