How to manage severe hyperglycemia (high blood sugar) in the Emergency Room (ER) setting?

Management of Severe Hyperglycemia (645 mg/dL) in the Emergency Room Setting

For severe hyperglycemia with blood glucose of 645 mg/dL in the ER setting, continuous intravenous insulin infusion is the most effective treatment method and should be initiated promptly after fluid resuscitation begins.

Initial Assessment and Categorization

1. Determine if the patient has:

   • Hyperosmolar Hyperglycemic State (HHS): glucose ≥600 mg/dL, effective serum osmolality ≥320 mOsm/kg, minimal ketones, pH >7.30 1
   • Diabetic Ketoacidosis (DKA): glucose ≥250 mg/dL, significant ketones, pH ≤7.30 1
   • Uncomplicated severe hyperglycemia

2. Obtain immediately:

   • Complete blood count
   • Comprehensive metabolic panel (electrolytes, BUN, creatinine)
   • Serum ketones
   • Arterial blood gases
   • Urinalysis
   • Calculated serum osmolality: 2[measured Na (mEq/L)] + glucose (mg/dL)/18 1
   • ECG
   • Cultures if infection suspected

Treatment Algorithm

Step 1: Fluid Resuscitation (Begin Immediately)

• Start with 0.9% normal saline at 15-20 mL/kg/hour for the first hour 1
• After initial stabilization, may switch to 0.45% saline depending on sodium levels and hydration status 1
• Total fluid deficit should be corrected over 24 hours for adults 1
• Monitor fluid status carefully to avoid overhydration in patients with cardiac or renal compromise

Step 2: Insulin Therapy (Begin 1-2 hours after starting fluids)

• Administer IV insulin bolus of 0.15 U/kg of regular insulin 1
• Follow with continuous IV insulin infusion at 0.1 U/kg/hour (typically 5-7 U/hour in adults) 1
• Adjust insulin infusion rate based on validated protocols that account for glycemic fluctuations 2
• Target glucose reduction of 50-75 mg/dL per hour 1
• Once glucose reaches 200-250 mg/dL, consider reducing insulin infusion rate and adding dextrose to IV fluids to prevent hypoglycemia 2

Step 3: Electrolyte Management

• Monitor potassium levels closely and begin replacement when renal function is ensured 1
• Typical potassium replacement: 20-40 mEq/L when serum potassium is <5.0 mEq/L 1
• Monitor and replace phosphate and magnesium as needed
• For severe hyperkalemia, consider calcium administration to stabilize cardiac membranes 3

Step 4: Identify and Treat Precipitating Factors

• Common precipitants include:
  • Infection (most common) 4
  • Medication non-compliance
  • New-onset diabetes
  • Myocardial infarction
  • Stroke
  • Substance abuse 1

Transitioning from IV to Subcutaneous Insulin

1. Begin subcutaneous insulin 1-2 hours before discontinuing IV insulin 2
2. Convert to basal insulin at 60-80% of daily IV insulin requirement 2
3. For patients with good nutritional intake, use a basal-bolus insulin regimen 2
4. For patients with poor oral intake, use basal plus correction insulin regimen 2
5. Avoid using sliding scale insulin alone as the sole treatment strategy 2

Monitoring Parameters

• Blood glucose: Every 1 hour until stable, then every 2-4 hours
• Electrolytes: Every 2-4 hours initially, then every 4-6 hours
• Mental status: Ongoing assessment
• Fluid input/output: Hourly
• Vital signs: Every 1-2 hours until stable

Special Considerations

For HHS (likely with glucose of 645 mg/dL):

• More profound dehydration than DKA (average 9L deficit) 4
• Higher mortality rate than DKA 1
• More gradual correction of glucose to prevent complications 1
• Higher risk of thrombotic complications 1

For Patients with Renal Impairment:

• Adjust insulin doses downward as insulin clearance is reduced 2
• More careful fluid management to prevent volume overload 5
• Monitor for hypoglycemia more frequently 5

Potential Complications to Monitor

• Hypoglycemia (most common adverse event with insulin therapy) 6
• Hypokalemia during insulin treatment 6
• Cerebral edema (especially with rapid correction of hyperosmolality) 1
• Vascular occlusions (myocardial infarction, mesenteric artery occlusion) 4
• Rhabdomyolysis 4

Pitfalls to Avoid

1. Do not delay insulin therapy once fluid resuscitation has begun 1
2. Do not rely solely on sliding scale insulin regimens 2
3. Do not correct hyperglycemia too rapidly (aim for 50-75 mg/dL per hour) 1
4. Do not forget to search for and treat the underlying cause 4
5. Do not neglect fluid resuscitation before insulin administration (can worsen hypotension) 1
6. Do not forget to transition appropriately from IV to subcutaneous insulin 2

By following this structured approach to managing severe hyperglycemia in the ER, you can effectively reduce blood glucose levels while minimizing the risk of complications.