What is the primary cause of death in diabetic ketoacidosis (DKA)?

Primary Causes of Death in Diabetic Ketoacidosis

The primary causes of death in diabetic ketoacidosis (DKA) include cerebral edema, cardiac arrhythmias due to electrolyte disturbances, and complications from severe volume depletion leading to shock and multiorgan failure. 1

Cerebral Edema

• Cerebral edema is a rare but frequently fatal complication of DKA, occurring in 0.7-1.0% of children with DKA 1
• When cerebral edema develops, mortality is extremely high (>70%), with only 7-14% of patients recovering without permanent morbidity 1
• Most common in children with newly diagnosed diabetes, but has been reported in children with known diabetes and in young adults in their twenties 1
• Fatal cases have also been reported in patients with hyperosmolar hyperglycemic state (HHS) 1

Pathophysiology and Risk Factors

• Likely results from osmotically driven movement of water into the central nervous system when plasma osmolality declines too rapidly during treatment 1
• Risk factors include:
  • Rapid correction of hyperglycemia
  • Excessive fluid administration
  • Failure to add dextrose when blood glucose reaches 250 mg/dl 1

Prevention

• Gradual replacement of sodium and water deficits in hyperosmolar patients (maximal reduction in osmolality 3 mOsm kg–1 H2O h–1) 1
• Addition of dextrose to hydrating solutions once blood glucose reaches 250 mg/dl 1
• Maintaining glucose levels of 250-300 mg/dl until hyperosmolarity and mental status improve in HHS patients 1

Cardiac Arrhythmias

• Electrolyte imbalances, particularly potassium abnormalities, can trigger potentially fatal cardiac arrhythmias in DKA patients 2
• Volume depletion leads to hemodynamic stress on the heart, increasing arrhythmia risk 2

Risk Factors

• Severity of electrolyte disturbances, particularly hypokalemia during treatment 2
• Degree of dehydration and hemodynamic compromise 2
• Pre-existing cardiac disease

Prevention and Management

• Continuous cardiac monitoring in severe DKA (pH < 7.0, bicarbonate < 10 mEq/L) 2
• Careful monitoring of electrolytes, especially potassium, every 2-4 hours during treatment 2
• Potassium replacement when serum levels fall below 5.5 mEq/L to prevent hypokalemia-induced arrhythmias 2

Hypoxemia and Pulmonary Complications

• Hypoxemia and, rarely, noncardiogenic pulmonary edema may complicate DKA treatment 1
• Attributed to reduced colloid osmotic pressure resulting in increased lung water content and decreased lung compliance 1
• Higher risk in patients with:
  • Widened alveolo-arteriolar oxygen gradient on initial blood gas
  • Pulmonary rales on physical examination 1

Other Complications Contributing to Mortality

• Severe dehydration leading to shock and multiorgan failure 1
• Complications from underlying precipitating factors (e.g., severe infection, myocardial infarction) 1
• Treatment complications:
  • Hypoglycemia due to overzealous insulin treatment
  • Hypokalemia from insulin administration and bicarbonate treatment
  • Hyperglycemia from interruption of insulin therapy 1

Mortality Rates and Risk Factors

• Overall mortality rate in DKA is approximately 5% in experienced centers 1
• Mortality is substantially higher at extremes of age and in patients presenting with coma and hypotension 1
• HHS has a higher mortality rate (approximately 15%) compared to DKA 1
• Hypothermia, if present, is a poor prognostic sign 1

Prevention Strategies

• Better access to medical care and patient education 1
• Addressing socioeconomic barriers to insulin access 1
• Sick-day management education including:
  • When to contact healthcare providers
  • Blood glucose goals during illness
  • Use of supplemental short-acting insulin
  • Never discontinuing insulin 1
• Early recognition and treatment of precipitating factors 1