What is the management for a patient with severe hyperglycemia (blood sugar level greater than 500 mg/dL)?

Management of Severe Hyperglycemia (Blood Sugar >500 mg/dL)

For patients with severe hyperglycemia (blood sugar >500 mg/dL), immediate treatment with intravenous insulin, aggressive fluid rehydration, and electrolyte monitoring is essential to prevent life-threatening complications. 1

Initial Assessment and Management

• Evaluate for signs of diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) by checking arterial blood gases, electrolytes, renal function, and ketones 1
• Start intravenous fluid resuscitation immediately with 0.9% NaCl at a rapid rate (typically 15-20 mL/kg in the first hour) to correct dehydration 1
• Begin intravenous regular insulin therapy with an initial bolus of 0.1 units/kg (for adults) followed by continuous infusion at 0.1 units/kg/hour 1
• If glucose does not decrease by 50-75 mg/dL in the first hour, double the insulin infusion rate until a steady glucose decline is achieved 1
• Monitor potassium levels closely as hypokalaemia is common (approximately 50% of cases) during treatment and is associated with increased mortality 1

Fluid Management

• After initial bolus, continue IV fluids at 1.5 times the 24-hour maintenance requirements (approximately 5 mL/kg/hour) 1
• Adjust fluid type based on serum sodium levels - typically use 0.45-0.9% NaCl depending on corrected sodium values 1
• When blood glucose reaches 250 mg/dL, change to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 1
• For HHS specifically, distribute fluid deficit evenly over 48 hours to prevent rapid changes in osmolality 1

Electrolyte Replacement

• Add potassium (20-40 mEq/L) to IV fluids once renal function is confirmed and serum potassium is known to be normal or low 1
• Use a mixture of potassium chloride and potassium phosphate (2/3 KCl and 1/3 KPO₄) for optimal replacement 1
• Monitor electrolytes (particularly potassium) every 2-4 hours during the acute management phase 1

Monitoring During Treatment

• Check blood glucose hourly until stable, then every 2-4 hours 1
• Monitor mental status regularly to identify changes that might indicate iatrogenic complications such as cerebral edema 1
• For patients with DKA, monitor for resolution of ketosis (preferably by direct measurement of β-hydroxybutyrate) 1
• Check arterial blood gases and electrolytes every 2-4 hours until stabilized 1

Transition to Subcutaneous Insulin

• Once the patient is stable with glucose <250 mg/dL, anion gap normalized, and able to eat, transition to subcutaneous insulin 1
• Calculate the total daily insulin requirement based on the IV insulin rate over the previous 6-12 hours 1
• For a patient receiving an average of 1.5 units per hour, the estimated daily dose would be approximately 36 units/24 hours 1
• Administer first dose of subcutaneous insulin 1-2 hours before discontinuing the insulin infusion to prevent rebound hyperglycemia 1
• Use a basal-bolus insulin regimen rather than sliding scale insulin alone for better glycemic control 2

Special Considerations

• For patients with Type 2 diabetes and severe hyperglycemia without significant metabolic derangements, treatment with a sulfonylurea, GLP-1 receptor agonist, or dual GIP and GLP-1 receptor agonist may be considered as an alternative to insulin, though evidence is limited for patients with blood glucose >500 mg/dL 1
• In patients with renal impairment, adjust insulin doses and monitor more frequently for hypoglycemia 2
• For patients with persistent hyperglycemia and complications such as non-healing wounds, a basal-bolus insulin regimen with a target glucose range of 140-180 mg/dL is recommended 2

Common Pitfalls to Avoid

• Relying solely on sliding-scale insulin for management of severe hyperglycemia 2
• Failing to monitor and replace potassium, which can lead to life-threatening arrhythmias 1
• Correcting hyperglycemia too rapidly, which can precipitate cerebral edema, particularly in children and young adults 1
• Discontinuing IV insulin before subcutaneous insulin has had time to take effect 1
• Setting overly aggressive glycemic targets in patients with renal impairment, which increases hypoglycemia risk 2