How to manage ketosis in a Type 2 Diabetes Mellitus (T2DM) patient who is not yet eating?

Management of Ketosis in T2DM Patients Who Are Not Yet Eating

Insulin therapy must be initiated for T2DM patients with ketosis who are not yet eating, as this is essential to prevent progression to diabetic ketoacidosis, resolve metabolic abnormalities, and avoid serious complications including coma or death. 1

Initial Assessment and Management

• Evaluate severity of ketosis:

  • Check blood glucose, venous blood gases, electrolytes, BUN, creatinine, and urine analysis
  • Measurement of β-hydroxybutyrate in blood is preferred for monitoring ketosis 1
  • Assess for mental status changes, dehydration, and acidosis

• Fluid replacement:

  • Begin with intravenous fluid replacement to correct dehydration
  • Use isotonic saline initially, with rate adjusted based on hemodynamic status
  • Typically 1.5 times maintenance requirements will accomplish smooth rehydration 1

Insulin Administration

• For patients with ketosis:

  • Initiate insulin therapy immediately
  • Use continuous intravenous regular insulin infusion (preferred method) 1
  • Initial dose: 0.1 units/kg/hour
  • Adjust insulin rate based on blood glucose response (decrease by 50% when glucose falls below 200 mg/dL)

• For mild ketosis without acidosis:

  • Consider subcutaneous insulin regimen with a "priming" dose of regular insulin (0.4-0.6 units/kg), half as IV bolus and half as subcutaneous injection
  • Follow with 0.1 unit/kg subcutaneously hourly 1

Monitoring and Adjustments

• Frequent monitoring:

  • Check blood glucose every 1-2 hours
  • Monitor electrolytes, venous pH, and anion gap every 2-4 hours
  • Assess β-hydroxybutyrate levels if available (preferred over urine ketones) 1

• Continue insulin until:

  • Blood glucose < 200 mg/dL
  • Serum bicarbonate ≥ 18 mEq/L
  • Venous pH ≥ 7.3 1

Transition to Oral Intake

• When patient remains NPO (not eating):

  • Continue IV insulin and fluid replacement
  • Supplement with subcutaneous regular insulin as needed every 4 hours
  • For adults, give 5-unit increments for every 50 mg/dL increase in blood glucose above 150 mg/dL (up to 20 units for blood glucose of 300 mg/dL) 1

• When patient can eat:

  • Transition to subcutaneous insulin regimen using combination of short/rapid-acting and intermediate/long-acting insulin
  • Continue IV insulin infusion for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 1
  • Do not abruptly discontinue IV insulin as this can lead to poor glycemic control

Special Considerations

• Electrolyte management:

  • Monitor and replace potassium as needed (target 4-5 mEq/L)
  • Consider phosphate replacement only if serum phosphate < 1.0 mg/dL or in patients with cardiac dysfunction, anemia, or respiratory depression 1

• Carbohydrate intake when resuming eating:

  • When oral intake is possible, provide 150-200g carbohydrate daily (45-50g every 3-4 hours) to prevent starvation ketosis 1
  • If regular food is not tolerated, use liquid or soft carbohydrate-containing foods (juices, soups, etc.) 1

Pitfalls to Avoid

• Do not rely on nitroprusside method (urine ketones) to monitor response to therapy, as it doesn't measure β-hydroxybutyrate and may falsely suggest worsening ketosis during treatment 1

• Never omit insulin in T2DM patients with ketosis, even during acute illness 1

• Avoid abrupt discontinuation of IV insulin when transitioning to subcutaneous regimen 1

• Prevent hypoglycemia by reducing insulin dose and providing glucose-containing fluids when blood glucose falls below 200 mg/dL

By following this approach, ketosis in T2DM patients who are not yet eating can be effectively managed, preventing progression to more severe complications and allowing for safe transition to oral intake when appropriate.