Recommended Glucose Levels and Treatment Strategies for Hospitalized Patients
For hospitalized patients with hyperglycemia, initiate insulin therapy when blood glucose persistently exceeds 180 mg/dL (checked on two occasions), and maintain glucose levels between 140-180 mg/dL for both critically ill and non-critically ill patients. 1
Glycemic Targets
Standard Target Range
- Start insulin therapy at a threshold of ≥180 mg/dL (10.0 mmol/L) for persistent hyperglycemia 1
- Once insulin is initiated, target glucose range of 140-180 mg/dL (7.8-10.0 mmol/L) applies to the majority of both critically ill and non-critically ill patients 1
- This target range is supported by the NICE-SUGAR trial, which demonstrated that intensive glycemic control (80-110 mg/dL) resulted in 10- to 15-fold greater rates of hypoglycemia and slightly higher mortality (27.5% vs. 25%) compared to moderate targets 1
More Stringent Targets (Selected Patients Only)
- Targets of 110-140 mg/dL (6.1-7.8 mmol/L) or 100-180 mg/dL (5.6-10.0 mmol/L) may be appropriate for select patients such as critically ill postsurgical patients or cardiac surgery patients, only if achievable without significant hypoglycemia 1
- For non-critically ill patients with previous tight outpatient glycemic control who are clinically stable, targets below 140 mg/dL may be considered 1
Less Stringent Targets
- Glycemic levels >250 mg/dL (13.9 mmol/L) may be acceptable in terminally ill patients with short life expectancy, using less aggressive insulin regimens to minimize glucosuria, dehydration, and electrolyte disturbances 1
Blood Glucose Monitoring
Monitoring Frequency
- For patients eating meals: perform point-of-care (POC) glucose monitoring before meals 1
- For patients not eating (NPO): monitor glucose every 4-6 hours 1
- For patients on intravenous insulin: monitor every 30 minutes to 2 hours as this is the required standard for safe IV insulin use 1
Hypoglycemia Prevention
- Reassess the insulin regimen when blood glucose falls below 100 mg/dL (5.6 mmol/L) to avoid hypoglycemia, as fasting glucose <100 mg/dL predicts hypoglycemia within the next 24 hours 1
- Modify the regimen when blood glucose values are <70 mg/dL (3.9 mmol/L) unless easily explained by factors such as a missed meal 1
Insulin Treatment Strategies
Critically Ill Patients (ICU Setting)
- Continuous intravenous insulin infusion is the preferred method for achieving glycemic targets in the ICU 1
- Use validated written or computerized protocols that allow for predefined adjustments in insulin infusion rate based on glycemic fluctuations 1
- Insulin infusion protocols with demonstrated safety and efficacy resulting in low rates of hypoglycemia are highly recommended 1
Non-Critically Ill Patients
For Patients with Good Nutritional Intake
- A basal-bolus-correction insulin regimen is the preferred treatment, consisting of basal insulin, prandial (nutritional) insulin, and correction insulin components 1
- This regimen is more effective than sliding scale insulin alone 1
For Patients with Poor or No Oral Intake
- Basal insulin plus correction insulin is the preferred regimen for patients with poor oral intake or who are NPO 1
- A single dose of long-acting insulin plus correction insulin is appropriate for this population 2
Critical Pitfall to Avoid
- The sole use of sliding scale insulin (SSI) in the inpatient hospital setting is strongly discouraged as it is ineffective for glycemic control and excludes the essential basal insulin component 1
Insulin Formulations
Preferred Insulin Types
- Long-acting basal insulin analogs (glargine, detemir) are preferred for the basal component of therapy due to their physiological time-action profiles and lower propensity for inducing hypoglycemia compared to NPH insulin 3
- Rapid-acting insulin analogs (aspart, lispro, glulisine) are recommended for bolus and correction doses 3
Special Considerations
Older Adults
- Target blood glucose between 140-180 mg/dL (7.8-10 mmol/L) for most elderly patients, but glycemic targets should be individualized based on clinical status, risk of hypoglycemia, and presence of diabetes complications 1
- Noninsulin regimens with dipeptidyl peptidase 4 (DPP-4) inhibitors alone or in combination with basal insulin may represent an alternative to basal-bolus regimens in elderly patients 1
Admission Assessment
- Measure HbA1c at admission if results from the previous 3 months are not available, as an admission A1C ≥6.5% (48 mmol/mol) suggests diabetes preceded hospitalization 1, 4
- Consider obtaining an A1C in patients with risk factors for undiagnosed diabetes who exhibit hyperglycemia in the hospital 1
Consultation
- Consult with a specialized diabetes or glucose management team when possible, as appropriately trained specialists can reduce length of stay, improve glycemic control, and improve outcomes 1
Common Clinical Pitfalls
Avoid overly aggressive glucose targets (<110 mg/dL) as they increase hypoglycemia risk without additional benefit and may increase mortality 1, 5
Do not use sliding scale insulin as monotherapy - it is ineffective and strongly discouraged by all major guidelines 1
Prevent rebound hyperglycemia when transitioning from IV to subcutaneous insulin by starting subcutaneous insulin 1-2 hours before stopping the IV infusion 6
Monitor for hypoglycemia triggers including sudden reduction of corticosteroid dose, altered nutritional state, reduced oral intake, new NPO status, and inappropriate timing of insulin relative to meals 1