What is diabetic ketoacidosis (DKA)?

Diabetic Ketoacidosis (DKA)

Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes characterized by insulin deficiency resulting in hyperglycemia, ketosis, and metabolic acidosis that requires immediate medical attention. 1

Definition and Pathophysiology

• DKA results from absolute or relative insulin deficiency combined with elevated counterregulatory hormones (glucagon, catecholamines, cortisol, growth hormone) leading to hyperglycemia, ketosis, and metabolic acidosis 2, 1
• The primary acid-base disturbance is a high anion gap metabolic acidosis from accumulation of ketone bodies in the blood 2, 1
• DKA can occur in both type 1 and type 2 diabetes, but is more common in type 1 diabetes 3
• Euglycemic DKA (blood glucose <200 mg/dL) can occur in approximately 10% of cases, particularly in patients using SGLT2 inhibitors, during pregnancy, with reduced food intake, alcohol use, or liver failure 2, 1

Diagnostic Criteria

DKA is generally diagnosed by the triad of:

• Hyperglycemia (blood glucose >250 mg/dL), though this criterion has been de-emphasized due to euglycemic DKA 3
• Metabolic acidosis (pH <7.3, serum bicarbonate <18 mEq/L, anion gap >10 mEq/L) 2, 3
• Elevated serum or urine ketones 2, 3

DKA severity is categorized based on acidosis level:

• Mild: venous pH 7.25-7.30, bicarbonate 15-18 mEq/L 2
• Moderate: venous pH 7.00-7.24, bicarbonate 10-<15 mEq/L 2
• Severe: venous pH <7.00, bicarbonate <10 mEq/L 2

Clinical Presentation

• Common symptoms include polyuria, polydipsia, nausea, vomiting, abdominal pain, weight loss, and severe fatigue 3
• Physical examination may reveal poor skin turgor, Kussmaul respirations (deep, rapid breathing), tachycardia, hypotension, and altered mental status 2
• Mental status can range from full alertness to profound lethargy or coma, with the latter being more common in severe cases 2
• Up to 25% of DKA patients have emesis, which may be coffee-ground in appearance due to hemorrhagic gastritis 2

Risk Factors

• Insulin omission or inadequate insulin dosing 2
• Infection or acute illness 2, 4
• New-onset diabetes (particularly in children) 2
• Psychological stress 2
• Certain medications (especially SGLT2 inhibitors) 2, 1
• Pregnancy (can present with euglycemic DKA) 2
• Social determinants of health (inadequate health insurance, complex childcare arrangements) 2

Laboratory Evaluation

Essential tests for DKA diagnosis and management include:

• Blood glucose levels 2, 3
• Arterial blood gases to assess pH and bicarbonate levels 1
• Serum electrolytes with calculated anion gap 1
• Serum or urine ketones 1, 3
• Complete blood count with differential 3
• Blood urea nitrogen and creatinine 3
• Electrocardiography to assess for cardiac complications 3

Treatment

The management of DKA focuses on four key areas:

1. Fluid Replacement

   • Initial fluid therapy with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr during the first hour to expand intravascular volume and restore renal perfusion 2
   • Subsequent fluid therapy adjusted based on hemodynamic status, electrolyte levels, and urine output 5

2. Insulin Therapy

   • Intravenous insulin administration to correct hyperglycemia and suppress ketogenesis 1, 4
   • Never discontinue basal insulin, even when not eating, to prevent DKA occurrence or worsening 2

3. Electrolyte Management

   • Close monitoring and replacement of potassium is crucial, as insulin therapy drives potassium into cells 2, 4
   • Bicarbonate administration is generally not recommended, even with severe acidosis 1

4. Identifying and Treating Precipitating Factors

   • Search for and treat underlying causes such as infection, myocardial infarction, or medication non-adherence 5, 6

Monitoring and Complications

• Frequent monitoring of vital signs, mental status, fluid balance, and laboratory parameters is essential 6
• Potential complications include cerebral edema (especially in children), acute respiratory distress syndrome, thromboembolism, and acute kidney injury 7
• The overall mortality for DKA in children is 1-3%, with higher risk in severe cases 2

Prevention

• Patient education on diabetes management, especially during illness 2
• Regular blood glucose monitoring and ketone testing when glucose levels exceed 200 mg/dL 2
• Ensuring uninterrupted access to insulin and diabetes supplies 3
• 24-hour availability of healthcare team contact for patients with concerning symptoms 2
• Identification of high-risk patients, including those with recurrent DKA episodes 2

Special Considerations

• Recurrent DKA is often associated with insulin omission, psychiatric illness (especially depression), and eating disorders 2
• Pregnant individuals may present with euglycemic DKA and require immediate medical attention due to significant risk of feto-maternal harm 2
• Patients using SGLT2 inhibitors have an increased risk of euglycemic DKA 2, 1