Hyperglycemia occurs in up to 50% of ICU patients due to underlying conditions like diabetes or stress-related illnesses and steroids. Early studies found decreased mortality with intensive glucose control, but later larger trials were stopped due to lack of benefit and increased risk of hypoglycemia. While hyperglycemia can have ill effects, hypoglycemia can cause brain damage or death within minutes. Current consensus recommends liberalizing glucose control to a range of 140-180 mg/dL due to weak evidence of benefit from intensive control and risk of harm from hypoglycemia and glucose fluctuations.

1. Glycemic Control in the ICU
Steven Podnos MD

2. Hyperglycemia
• Occurs in up to 50% of ICU patients due to
underlying DM , steroids, and/or stress of
illness
• Is a MARKER of worse outcomes in many
different ICU illnesses

3. Control of Glucose in ICU
• One early study (van den Berghe) found a
decreased mortality with intensive control of
glucose (IIT), but was limited to Cardiac
Surgery patients , often on TPN
• Two large recent trials of IIT were stopped due
to 1) lack of benefit with IIT and 2) increased
hypoglycemia

4. Stress Hormones and Hyperglycemia
• Glucagon,Glucocorticoids,Norepinephrine
• Epinephrine
• Tumor Necrosis factor
• All these hormones are secreted with stress
of illness and produce elevated glucose
through various methods

5. Ill Effects of Hyperglycemia
• Direct Immune suppression
• Excess insulin causes cellular damage
• Direct cellular toxicity and release of
inflammatory mediators in presence of
hyperglycemia

6. Hypoglycemia
• Brain requires adequate glucose levels or
coma/death results in minutes

7. Why is Consensus Changing?
• Early studies suggested benefit to Intensive
Insulin Therapy (IIT)
• Later studies do not-some show harm from
hypoglycemia and no mortality benefit
• Studies differ in many variables: SICU vs
MICU, parenteral vs enteral nutrition, degree
of illness (APACHE 2 scores), intensity of
control
• More studies pending

8. Recommendations
• Current consensus seems to be liberalizing
glucose control to 140-180.
• Evidence weak of benefit
• Some suggest it is swings in glucose levels that
may be harmful rather than absolute levels.
• May be more appropriate to use constant
insulin drip to keep levels higher than sliding
scale which has more glucose fluctuations
(unproven)