What is the appropriate dose of regular insulin (Novolin) for an intravenous (IV) push in a patient with severe hyperglycemia (glucose level of 968 mg/dL)?

Emergency Management of Severe Hyperglycemia (Glucose 968 mg/dL)

For a patient with severe hyperglycemia (glucose 968 mg/dL), do NOT give an IV push bolus of regular insulin—instead, initiate a continuous IV insulin infusion at 0.1 units/kg/hour after an initial IV bolus of 0.1 units/kg, following standard hyperglycemic crisis protocols. 1, 2

Critical Initial Assessment

Before administering any insulin, you must immediately check serum potassium levels 1, 2:

• If potassium <3.3 mEq/L: DO NOT start insulin 2

  • Begin aggressive potassium repletion first (20-40 mEq/L in IV fluids using 2/3 KCl and 1/3 KPO4) 2
  • Obtain ECG to assess cardiac effects 2
  • Delay insulin until K+ ≥3.3 mEq/L to prevent life-threatening arrhythmias and death 2

• If potassium ≥3.3 mEq/L: Proceed with insulin protocol 1, 2

Fluid Resuscitation (Start Immediately)

Begin isotonic saline at 15-20 mL/kg/hour for the first hour while awaiting potassium results 1, 2. This glucose level (968 mg/dL) meets criteria for hyperosmolar hyperglycemic state (HHS) if pH >7.3 and bicarbonate >15 mEq/L, or diabetic ketoacidosis (DKA) if pH <7.3 and bicarbonate <15 mEq/L 1.

Insulin Protocol (Once K+ ≥3.3 mEq/L)

Continuous IV insulin infusion is the only appropriate therapy for this degree of hyperglycemia—IV push dosing is not a standard protocol 1:

1. Initial bolus: 0.1 units/kg IV regular insulin 1, 2
2. Continuous infusion: 0.1 units/kg/hour IV regular insulin 1, 2
3. Target glucose decline: 50-75 mg/dL per hour 1, 2

Monitoring and Adjustment

• Check blood glucose every 1 hour initially 1, 2
• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration, then double the insulin infusion rate every hour until achieving steady decline of 50-75 mg/dL/hour 2
• Check electrolytes, BUN, creatinine, and venous pH every 2-4 hours 1, 2
• Once glucose reaches 200 mg/dL, add dextrose to IV fluids and reduce insulin infusion to 0.05-0.1 units/kg/hour 2

Common Pitfalls to Avoid

Never give insulin as an IV push for severe hyperglycemia 1, 2. The pharmacologic effect of IV regular insulin begins at 10-15 minutes and terminates at approximately 4 hours 3, making continuous infusion necessary for sustained control. A single IV push would cause unpredictable glucose fluctuations and potential severe hypoglycemia 1.

Do not use subcutaneous insulin for this level of hyperglycemia 1. Continuous insulin infusion remains the therapy of choice for severe hyperglycemia (>300 mg/dL) 1, and subcutaneous insulin should be avoided in critically ill patients, particularly during hypotension or shock 1.

Transition to Subcutaneous Insulin

Only transition when ALL of the following criteria are met 2:

• Glucose <200 mg/dL
• pH >7.3 (if DKA)
• Bicarbonate ≥18 mEq/L (if DKA)
• Anion gap ≤12 mEq/L (if DKA)
• Patient can tolerate oral intake

Administer basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE stopping IV insulin to prevent rebound hyperglycemia 2. Continue IV insulin for 1-2 hours after giving subcutaneous insulin 2.

Target Glucose Range

For critically ill patients, maintain glucose between 140-180 mg/dL once initial crisis is controlled 1. More stringent targets (110-140 mg/dL) may be appropriate for cardiac surgery patients but increase hypoglycemia risk 1.