How to manage severe hyperglycemia?

Management of Severe Hyperglycemia (Blood Glucose 511 mg/dL)

Immediate treatment with intravenous insulin is required for a blood glucose of 511 mg/dL, with an initial bolus of 0.1 units/kg followed by continuous insulin infusion at 0.1 units/kg/hour, targeting a gradual reduction to 140-180 mg/dL. 1

Initial Assessment and Management

• Evaluate for diabetic emergencies:

  • Check for symptoms of diabetic ketoacidosis (DKA): polyuria, polydipsia, nausea, vomiting, abdominal pain, fruity breath odor
  • Assess for hyperosmolar hyperglycemic state (HHS): altered mental status, extreme dehydration
  • Order laboratory tests: serum electrolytes, ketones, arterial blood gases, complete blood count

• Immediate interventions:

  1. Start IV fluids with normal saline at 15-20 mL/kg/hour for the first hour to correct dehydration
  2. Administer IV insulin as noted above
  3. Monitor blood glucose hourly until stable, then every 2-4 hours

Insulin Management Protocol

For this severe hyperglycemia (511 mg/dL), follow this approach:

1. Initial phase:

   • IV insulin is preferred over subcutaneous insulin due to faster onset and better titration capability 2
   • Begin with insulin bolus of 0.1 units/kg followed by continuous infusion at 0.1 units/kg/hour
   • Target a glucose reduction of 50-75 mg/dL per hour to avoid rapid shifts 1

2. Adjustment phase:

   • Titrate insulin infusion rate based on hourly glucose measurements
   • Increase rate by 1-2 units/hour if glucose is not decreasing by at least 50 mg/dL/hour
   • Decrease rate if glucose is falling too rapidly (>100 mg/dL/hour) to prevent hypoglycemia

3. Target range:

   • Aim for blood glucose of 140-180 mg/dL for most hospitalized patients 1
   • Avoid targets below 110 mg/dL due to increased risk of hypoglycemia 3

Monitoring and Supportive Care

• Fluid and electrolyte management:

  • Monitor potassium levels closely as insulin therapy will drive potassium into cells
  • Replace potassium if levels fall below 4.0 mEq/L to prevent cardiac arrhythmias
  • Monitor for signs of fluid overload, especially in patients with cardiac or renal disease

• Blood glucose monitoring:

  • Check blood glucose hourly until stable in target range for 4 hours
  • Then decrease to every 2-4 hours if stable 1
  • Monitor for hypoglycemia (blood glucose <70 mg/dL), which requires immediate treatment

Transition to Subcutaneous Insulin

Once blood glucose is controlled (140-180 mg/dL) and the patient is clinically stable:

1. Calculate 24-hour insulin requirements based on the last 6-8 hours of IV insulin use
2. Administer basal insulin (long-acting insulin) 2-4 hours before discontinuing IV insulin 2, 1
3. Implement basal-bolus insulin regimen rather than sliding scale alone:
   • 50% of total daily dose as basal insulin
   • 50% as prandial insulin divided between meals
   • Add correction doses based on pre-meal glucose levels

Common Pitfalls to Avoid

• Do not discontinue IV insulin abruptly without overlapping subcutaneous insulin
• Do not rely solely on sliding scale insulin, which is strongly discouraged 1
• Avoid rapid correction of severe hyperglycemia, which can lead to cerebral edema
• Never hold basal insulin for patients with type 1 diabetes, even when NPO 1
• Be vigilant for hypoglycemia, especially when insulin doses are being adjusted

Special Considerations

• Identify and treat underlying causes of severe hyperglycemia:

  • Infection/sepsis
  • Medication effects (glucocorticoids, thiazides)
  • Acute illness or stress
  • Missed insulin doses

• For patients with DKA:

  • Continue insulin infusion until anion gap normalizes
  • Monitor for resolution of ketosis
  • Transition to subcutaneous insulin only after metabolic acidosis resolves

This structured approach to managing severe hyperglycemia prioritizes rapid but controlled glucose reduction while minimizing risks of complications, particularly hypoglycemia and electrolyte disturbances, to improve patient outcomes related to morbidity and mortality.