What is the target glucose range for a critically ill patient?

Glucose Target for Critically Ill Patients

For critically ill patients, target a glucose range of 140-180 mg/dL (7.8-10.0 mmol/L), initiating insulin therapy when glucose persistently exceeds 180 mg/dL on two occasions. 1

Initiation Threshold

• Start insulin therapy when blood glucose is ≥180 mg/dL (10.0 mmol/L) checked on two occasions, not as a single isolated value 1
• This threshold applies to both critically ill and non-critically ill hospitalized patients 1
• Intravenous insulin is the treatment of choice for critically ill patients due to rapid onset and offset of action 2

Standard Target Range

• Once insulin is initiated, maintain glucose between 140-180 mg/dL (7.8-10.0 mmol/L) for the majority of critically ill patients 1
• This recommendation is based on the NICE-SUGAR trial, which demonstrated that intensive glycemic control (80-110 mg/dL) resulted in significantly higher mortality (27.5% vs 25%) and 10- to 15-fold greater rates of hypoglycemia compared to moderate targets 1
• The 140-180 mg/dL range balances glycemic control benefits against hypoglycemia risk, which is itself a marker of poor outcomes 2, 3

More Stringent Targets for Selected Patients

Consider tighter control of 110-140 mg/dL (6.1-7.8 mmol/L) only in specific populations where this can be achieved without significant hypoglycemia: 1

• Critically ill postsurgical patients 1
• Patients with cardiac surgery 1
• Patients with previous tight glycemic control who are clinically stable 1

Critical caveat: The Van den Berghe study initially showed 40% mortality reduction with intensive control (80-110 mg/dL) in surgical ICU patients, but subsequent trials failed to replicate these benefits and demonstrated harm 1

Alternative Target for Non-Critical Care

• For non-critically ill hospitalized patients, expert consensus supports a target range of 100-180 mg/dL (5.6-10.0 mmol/L) 1
• Premeal glucose targets <140 mg/dL (7.8 mmol/L) with random glucose <180 mg/dL (10.0 mmol/L) are reasonable if achievable safely 1

When to Accept Higher Glucose Levels

Less aggressive targets may be appropriate in specific circumstances:

• Patients with severe comorbidities may tolerate glucose between 180-250 mg/dL (10-13.9 mmol/L) where frequent monitoring is not feasible 1
• Terminally ill patients with short life expectancy may accept glucose >250 mg/dL (13.9 mmol/L) to minimize glucosuria and dehydration 1

Critical Safety Considerations

Hypoglycemia prevention is paramount:

• Fasting glucose <100 mg/dL predicts hypoglycemia within the next 24 hours 1
• Reassess insulin regimens when glucose falls to <100 mg/dL 2
• Studies consistently show that hypoglycemia rates increase dramatically with tighter targets, potentially contributing to increased mortality 1, 4

Common pitfall: Avoid targets <110 mg/dL or >180 mg/dL for general ICU populations, as these extremes are associated with worse outcomes 2, 3, 5

Glycemic Variability Matters

• Higher glycemic variability increases mortality even when mean glucose levels are similar 5
• Maintaining glucose within a specific range with minimal fluctuation is as important as the target itself 5
• Continuous glucose monitoring and closed-loop systems may help reduce variability, though not yet standard of care 6, 5

Implementation Strategy

Use validated intravenous insulin protocols that demonstrate:

• Efficacy in achieving the 140-180 mg/dL target 1
• Safety profile without increasing severe hypoglycemia risk 1
• Frequent glucose monitoring (every 30 minutes to 2 hours during IV insulin) 7

Avoid sliding scale insulin alone, which is strongly discouraged in all hospitalized patients 1, 2