When to recheck a patient's hyperglycemia after administering 3 units of Novolog (insulin aspart)?

When to Recheck Blood Glucose After Novolog Administration

Recheck the blood glucose level in 1-2 hours after administering 3 units of Novolog for a point-of-care glucose of 495 mg/dL. 1

Immediate Monitoring Protocol

For patients receiving insulin infusions or rapid-acting insulin corrections, blood glucose should be monitored every 1-2 hours until glucose values and insulin response are stable. 1 This frequent monitoring interval is critical for:

• Detecting the peak insulin effect, which occurs approximately 2-3 hours after subcutaneous Novolog administration 2
• Preventing hypoglycemia, as rapid-acting insulin analogs like Novolog (insulin aspart) have their maximal glucose-lowering effect within 1-3 hours 3, 4
• Assessing adequacy of the correction dose to determine if additional insulin is needed 1

Critical Considerations for This Clinical Scenario

Severe Hyperglycemia Requires Urgent Assessment

With an initial glucose of 495 mg/dL (27.5 mmol/L), this patient requires immediate evaluation for diabetic ketoacidosis or hyperosmolar hyperglycemic state. 1

Check capillary or serum ketones immediately in any patient with glucose >16.5 mmol/L (297 mg/dL) who has type 1 diabetes or is insulin-treated with type 2 diabetes. 1 If ketones are >2 mmol/L or urine ketones are moderate-to-large, this constitutes a medical emergency requiring hospital transfer. 1

Inadequate Dosing Concern

Three units of Novolog is likely insufficient for a glucose of 495 mg/dL. 5 Standard correction algorithms typically use:

• 4 units for glucose ≥180 mg/dL as a starting point for correction doses 5
• Higher correction factors (often 1 unit per 50 mg/dL above target) for severe hyperglycemia 5

For a glucose of 495 mg/dL, assuming a target of 130 mg/dL and an insulin sensitivity factor of 1:50, the expected correction dose would be approximately 7-8 units, not 3 units. 5

Monitoring Algorithm After Initial Recheck

At 1-2 Hours Post-Dose

• If glucose remains >300 mg/dL: Administer additional rapid-acting insulin using a correction scale and recheck in another 1-2 hours 1
• If glucose is 180-300 mg/dL: Continue monitoring every 1-2 hours until stable in target range 1
• If glucose is <180 mg/dL: May extend monitoring to every 2-4 hours once stable 1
• If glucose is <70 mg/dL: Treat hypoglycemia immediately with 15-20g of glucose and recheck in 15 minutes 1

Transition to Standard Monitoring

Once glucose values stabilize within target range (80-180 mg/dL) for 3-4 consecutive measurements, monitoring frequency can be reduced to every 4 hours. 1 However, many protocols with 4-hourly testing show hypoglycemia rates >10%, so more frequent monitoring (every 1-2 hours) is preferred during active insulin therapy. 1

Common Pitfalls to Avoid

• Waiting too long between glucose checks (>2 hours) during active correction of severe hyperglycemia can delay recognition of inadequate treatment or hypoglycemia 1
• Failing to assess for ketoacidosis in patients with glucose >300 mg/dL, particularly those with type 1 diabetes or insulin-treated type 2 diabetes 1
• Under-dosing correction insulin for severe hyperglycemia, leading to prolonged exposure to toxic glucose levels 5
• Not ensuring adequate hydration alongside insulin therapy for severe hyperglycemia 1

Additional Immediate Actions Required

Beyond rechecking glucose in 1-2 hours, this patient needs:

• Immediate ketone assessment (capillary beta-hydroxybutyrate or urine ketones) 1
• Aggressive hydration with IV or oral fluids 1
• Evaluation for precipitating factors (infection, medication non-adherence, new diagnosis of diabetes) 1
• Consideration of basal insulin initiation if not already prescribed, as a glucose of 495 mg/dL indicates severe insulin deficiency 5