What is the initial management of hyperglycemia (high sugar levels) in an emergency setting?

Emergency Management of Hyperglycemia

In the emergency management of hyperglycemia, intravenous regular insulin by continuous infusion at 0.1 units/kg/hour (5-7 units/hour in adults) is the treatment of choice for severe hyperglycemia, preceded by fluid resuscitation with isotonic saline at 10-20 ml/kg/hour initially. 1

Initial Assessment and Categorization

• Determine the type of hyperglycemic crisis: Diabetic Ketoacidosis (DKA) or Hyperosmolar Hyperglycemic State (HHS) by checking blood glucose, arterial pH, serum bicarbonate, ketones, and calculating effective serum osmolality 1
• DKA diagnostic criteria: blood glucose >250 mg/dl, arterial pH <7.3, bicarbonate <15 mEq/l, and presence of ketones 1
• HHS diagnostic criteria: blood glucose >600 mg/dl, arterial pH >7.3, bicarbonate >15 mEq/l, effective serum osmolality >320 mOsm/kg H₂O, and minimal ketonuria/ketonemia 1
• Obtain arterial blood gases, complete blood count, urinalysis, plasma glucose, blood urea nitrogen, electrolytes, chemistry profile, and creatinine levels immediately 1

Fluid Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 10-20 ml/kg/hour for the first hour to restore circulatory volume and renal perfusion 1
• In severely dehydrated patients, this may need to be repeated, but initial reexpansion should not exceed 50 ml/kg over the first 4 hours of therapy 1
• After initial stabilization, adjust fluid therapy to replace the deficit evenly over 48 hours 1
• For HHS patients, fluid losses are typically 100-220 ml/kg, requiring careful monitoring, especially in elderly patients 2
• When corrected serum sodium is normal or elevated, switch to 0.45% NaCl at appropriate rate 1

Insulin Therapy

• For severe hyperglycemia, after excluding hypokalemia (K+ <3.3 mEq/l), administer intravenous regular insulin as follows:
  • Adults: IV bolus of 0.15 units/kg body weight, followed by continuous infusion at 0.1 units/kg/hour (approximately 5-7 units/hour) 1
  • This regimen typically decreases plasma glucose at a rate of 50-75 mg/dl/hour 1
• If plasma glucose does not fall by 50 mg/dl in the first hour, check hydration status; if acceptable, double the insulin infusion rate hourly until achieving a steady glucose decline of 50-75 mg/hour 1
• When plasma glucose reaches 250 mg/dl in DKA or 300 mg/dl in HHS, decrease insulin infusion to 0.05-0.1 units/kg/hour (3-6 units/hour) and add 5-10% dextrose to IV fluids 1

Potassium Management

• Once renal function is assured and serum potassium is known, add 20-40 mEq/l potassium (2/3 KCl or potassium-acetate and 1/3 KPO₄) to the infusion 1
• Monitor potassium levels closely and adjust replacement according to serum levels 1

Monitoring and Adjustments

• Monitor blood glucose every 1-2 hours during insulin infusion 1
• Draw blood every 2-4 hours for determination of serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH (for DKA) 1
• Follow venous pH and anion gap to monitor resolution of acidosis rather than using nitroprusside method for ketones 1
• Target glucose levels between 140-180 mg/dl for critically ill patients 1
• For non-critically ill patients, target premeal glucose <140 mg/dl and random blood glucose <180 mg/dl 1

Special Considerations

• For mild DKA, subcutaneous or intramuscular regular insulin every hour can be effective, starting with a "priming" dose of 0.4-0.6 units/kg (half IV bolus, half SC/IM) 1
• In elderly patients, use more cautious fluid replacement to prevent fluid overload 1, 2
• For patients with acute ischemic stroke and hyperglycemia, maintain blood glucose in range of 140-180 mg/dl 1
• Monitor for hypoglycemia, especially in patients with risk factors such as renal dysfunction, low pre-treatment glucose, female gender, and no history of diabetes 3

Transition from IV to Subcutaneous Insulin

• When transitioning from IV to subcutaneous insulin, calculate doses based on the total IV insulin requirement over the previous 24 hours 1
• For total daily dose calculation: 1/2 of IV insulin/24h as basal insulin once daily, and 1/2 of IV insulin/24h divided by 3 as rapid-acting insulin per meal 1
• Ensure overlap between IV insulin discontinuation and first subcutaneous dose to prevent rebound hyperglycemia 1

Complications to Monitor

• Hypoglycemia: Monitor glucose levels frequently and adjust insulin accordingly 1, 4
• Hypokalemia: Replace potassium as needed based on serum levels 1
• Cerebral edema: Avoid rapid changes in serum osmolality; change should not exceed 3 mOsm/kg/hour 1
• Fluid overload: Monitor fluid input/output, vital signs, and clinical examination 1

Following these guidelines will help ensure effective and safe management of hyperglycemic emergencies while minimizing the risk of complications.