What is the recommended insulin correction dose for a patient with hyperglycemia (elevated blood glucose level of 12.3 mmol/L) at bedtime, who is on a standard sliding scale insulin regimen?

Bedtime Hyperglycemia Correction in Hospitalized Patients

For a blood glucose of 12.3 mmol/L (221 mg/dL) at bedtime in a hospitalized patient on sliding scale insulin, administer the prescribed correction dose of rapid-acting insulin according to the sliding scale protocol, but recognize that sliding scale insulin alone is inadequate and the patient requires immediate transition to a basal-bolus insulin regimen. 1, 2

Immediate Management

Correction Dose Administration

• Administer the prescribed sliding scale correction insulin (typically 2-4 units of rapid-acting insulin for glucose >13.9 mmol/L or 250 mg/dL) as ordered 3, 2
• For bedtime glucose of 12.3 mmol/L (221 mg/dL), a correction dose of 2 units of rapid-acting insulin is appropriate using simplified correction scales 3
• However, avoid using rapid-acting insulin at bedtime routinely, as this increases nocturnal hypoglycemia risk 3, 2

Critical Recognition

• A bedtime glucose of 12.3 mmol/L (221 mg/dL) exceeds the recommended target of <10.0 mmol/L (<180 mg/dL) for hospitalized patients and indicates inadequate glycemic control 1, 2
• Sliding scale insulin as monotherapy is explicitly condemned by all major diabetes guidelines and must be discontinued 3, 2

Transition to Appropriate Insulin Regimen

Basal-Bolus Regimen Implementation

• Immediately initiate basal insulin (glargine or detemir) at 0.3-0.5 units/kg/day for hospitalized patients, with half given as basal insulin once daily 3, 4
• Add prandial insulin (lispro, aspart, or glulisine) before meals at 4 units per meal or 10% of the basal dose 3, 4
• Randomized trials demonstrate that basal-bolus regimens provide superior glycemic control and reduce hospital complications compared to sliding scale insulin alone 2, 5

Target Glucose Ranges

• Target glucose range of 7.8-10.0 mmol/L (140-180 mg/dL) for most hospitalized patients 1, 6
• More stringent targets of 6.1-7.8 mmol/L (110-140 mg/dL) may be appropriate for selected patients if achievable without significant hypoglycemia 1
• Avoid targets <7.8 mmol/L (<140 mg/dL) in most hospitalized patients, as harms increase with lower targets 6

Monitoring Requirements

Glucose Monitoring Schedule

• Point-of-care glucose testing should be performed before meals for patients eating, or every 4-6 hours for patients not eating 1, 2
• Monitor closely for nocturnal hypoglycemia between midnight and 6:00 AM when risk peaks after bedtime insulin administration 2
• If glucose falls <5.6 mmol/L (<100 mg/dL), reassess the regimen; if <3.9 mmol/L (<70 mg/dL), reduce insulin dose by 10-20% immediately 3, 2

Documentation

• Document all insulin administrations and subsequent blood glucose readings in the medical record 2
• Ensure hypoglycemia treatment protocols are readily available 2

Common Pitfalls to Avoid

• Never continue sliding scale insulin as the sole treatment beyond the immediate correction—this leads to prolonged hyperglycemia and increased complications 3, 2
• Never withhold basal insulin when blood glucose is elevated, as this worsens hyperglycemia 2
• Avoid using rapid-acting insulin routinely at bedtime without concurrent basal insulin coverage, as this creates dangerous glucose variability 3, 2
• Do not delay transition to a physiologic basal-bolus regimen, as prolonged hyperglycemia increases infection risk and mortality 2, 7

Special Considerations

High-Risk Populations

• For elderly patients (>65 years), those with renal failure, or poor oral intake, use lower insulin doses (0.1-0.25 units/kg/day) to prevent hypoglycemia 3, 4
• Patients on high-dose home insulin (≥0.6 units/kg/day) should have their total daily dose reduced by 20% upon hospitalization 3, 4

Foundation Therapy

• Continue metformin unless contraindicated (worsening renal function, contrast studies, or acute illness) when initiating insulin therapy 3, 7
• Temporarily withhold sulfonylureas to avoid hypoglycemia in patients with limited caloric intake 7