What is the best course of action for a patient with a blood glucose level of hyperglycemia, who is on insulin therapy with a carb ratio of 1:5, and has a significantly elevated blood glucose reading of hyperglycemia?

Immediate Insulin Dose Adjustment for Severe Hyperglycemia

With a blood glucose of 383 mg/dL (21.3 mmol/L) and a carb ratio of 1:5, you need to immediately administer correction insulin using a correction factor (insulin sensitivity factor) and aggressively uptitrate your basal insulin dose by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL. 1

Calculate and Administer Correction Insulin Now

• Use your insulin sensitivity factor (ISF) to calculate correction dose: If you don't know your ISF, use the 1500 rule (1500 ÷ total daily insulin dose = ISF) or 1700 rule for more insulin-sensitive patients 1
• For a glucose of 383 mg/dL, subtract your target glucose (typically 100-120 mg/dL) and divide by your ISF to determine correction units needed 1
• Administer rapid-acting insulin (Humalog, Novolog, or Apidra) immediately - do NOT wait, as this level requires urgent correction 2
• Recheck blood glucose in 2-4 hours to assess response and determine if additional correction is needed 2

Aggressive Basal Insulin Titration Required

• Increase your basal insulin (Lantus/Toujeo/Levemir) by 4 units immediately since your fasting/pre-meal glucose is ≥180 mg/dL 1
• Continue increasing basal insulin by 4 units every 3 days until fasting glucose consistently reaches 80-130 mg/dL 1
• If fasting glucose drops to 140-179 mg/dL during titration, reduce increment to 2 units every 3 days 1
• Daily fasting blood glucose monitoring is essential during this titration phase 1

Critical Threshold: When to Add Prandial Insulin

• If your basal insulin dose exceeds 0.5 units/kg/day and glucose remains elevated, add prandial insulin rather than continuing to escalate basal insulin alone 1
• Start with 4 units of rapid-acting insulin before your largest meal or use 10% of your current basal dose 1
• Clinical signals that you need prandial insulin include: basal dose >0.5 units/kg/day, bedtime-to-morning glucose differential ≥50 mg/dL, hypoglycemia episodes, or high glucose variability 1

Verify Foundation Therapy

• Ensure you are taking metformin (at least 1000mg twice daily, up to 2500mg/day total) unless contraindicated - metformin should be continued even when intensifying insulin therapy 3, 1
• Consider adding a GLP-1 receptor agonist to improve glycemic control while minimizing weight gain and hypoglycemia risk if not already on one 3, 1

Understanding Your Carb Ratio

• Your carb ratio of 1:5 means 1 unit of insulin covers 5 grams of carbohydrate - this is separate from correction insulin 1
• Carb ratio addresses meal coverage; correction insulin addresses existing hyperglycemia - both may be needed simultaneously 1
• If post-meal glucose consistently exceeds target despite correct carb counting, adjust your carb ratio (e.g., from 1:5 to 1:4), not your basal insulin 1

Common Pitfalls to Avoid

• Do not blame inadequate meal coverage for fasting/pre-meal hyperglycemia of 383 mg/dL - this reflects inadequate basal insulin, not carb ratio issues 1
• Do not delay correction insulin administration - glucose >300 mg/dL requires immediate intervention 3, 2
• Do not continue escalating basal insulin beyond 0.5-1.0 units/kg/day without adding prandial coverage - this leads to "overbasalization" with increased hypoglycemia risk and suboptimal control 1
• Do not stop metformin when intensifying insulin unless specifically contraindicated 3, 1

When to Seek Immediate Medical Attention

• If you have symptoms of diabetic ketoacidosis (nausea, vomiting, abdominal pain, fruity breath odor, rapid breathing, confusion) - this requires emergency care 2
• If blood glucose remains >300 mg/dL despite correction insulin or if you develop symptoms of severe hyperglycemia (extreme thirst, frequent urination, blurred vision, weakness) 3
• If you experience severe hypoglycemia (glucose <40 mg/dL, loss of consciousness, seizures) after correction doses 1