Immediate Insulin Dose Adjustment Required
For a blood glucose of 478 mg/dL one hour after 3 units of Novolog (insulin aspart), you need to administer an additional correction dose of 4-6 units of rapid-acting insulin immediately and reassess the entire insulin regimen for inadequate basal and prandial coverage. 1
Immediate Correction Dose
Administer 4-6 units of rapid-acting insulin (Novolog/insulin aspart) immediately for a blood glucose of 478 mg/dL, as this represents severe hyperglycemia requiring prompt intervention 1, 2
Check blood glucose again in 2 hours to assess response and avoid insulin stacking 2
If blood glucose remains >300 mg/dL after 2 hours, consider an additional 2-4 unit correction dose 1
Critical Assessment: Why Did 3 Units Fail?
The fact that blood glucose is 478 mg/dL one hour after insulin indicates severe insulin deficiency requiring immediate regimen intensification:
3 units of rapid-acting insulin is grossly inadequate for this degree of hyperglycemia - this suggests either the patient is on insufficient basal insulin, has no established prandial insulin regimen, or is experiencing acute illness/stress 3, 1
Blood glucose ≥300 mg/dL indicates the need for basal-bolus insulin therapy, not isolated correction doses 3, 1
The patient likely requires 0.3-0.5 units/kg/day total daily insulin split between basal (50%) and prandial (50%) components for severe hyperglycemia of this magnitude 1
Urgent Regimen Restructuring
Establish Adequate Basal Insulin
Start or increase basal insulin (glargine/Lantus or detemir) to 10 units once daily or 0.2 units/kg/day if the patient is insulin-naive 1
If already on basal insulin, increase by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL 1
When basal insulin exceeds 0.5 units/kg/day without achieving control, add prandial insulin rather than continuing to escalate basal doses 1
Establish Prandial Insulin Coverage
Start with 4 units of rapid-acting insulin before each meal or 10% of the basal insulin dose 3, 1
Increase prandial doses by 1-2 units every 3 days based on 2-hour postprandial glucose readings 1
For blood glucose consistently >200 mg/dL, the patient needs both adequate basal coverage AND mealtime insulin, not just correction doses 1
Rule Out Acute Complications
Evaluate for diabetic ketoacidosis (DKA) if blood glucose >300 mg/dL with symptoms (nausea, vomiting, abdominal pain, altered mental status) 3
Check for ketonuria/ketonemia: if ketones present with glucose >300 mg/dL, this requires immediate evaluation for DKA and possible IV insulin therapy 3
Assess for precipitating factors: infection, medication non-adherence, steroid use, acute illness 3
Foundation Therapy Optimization
Ensure the patient is on metformin (unless contraindicated) at 1000-2000 mg daily, as this reduces total insulin requirements 1, 2
Consider adding an SGLT2 inhibitor or GLP-1 receptor agonist to reduce insulin requirements and improve glycemic control 3, 2
Critical Monitoring Requirements
Check blood glucose every 2-4 hours until consistently <200 mg/dL 3
Monitor for hypoglycemia 2-4 hours after each insulin dose when insulin action peaks 2
If hypoglycemia occurs, reduce the corresponding insulin dose by 10-20% immediately 3, 1
Common Pitfalls to Avoid
Do not rely solely on correction ("sliding scale") insulin - this is strongly discouraged and ineffective for long-term glycemic management 1, 2
Do not delay insulin intensification - blood glucose of 478 mg/dL represents severe hyperglycemia requiring immediate basal-bolus therapy 1, 2
Do not continue escalating correction doses without establishing adequate basal insulin - this leads to glucose variability and increased hypoglycemia risk 1
Do not ignore the possibility of DKA - any patient with glucose >300 mg/dL should be evaluated for ketones 3