A plea for intense glucose management to control hyperglycemia in the ICU

IV insulin infusion protocols reduce hyperglycemia and other hospital morbidities.

As practitioners understand, we are seeing an epidemic of diabetes. Currently at least 7% of the U.S. population or more than 20 million people are affected.

Sadly, when I make rounds it is also disappointing to see that glycemia control seems to be poorly managed among hospitalized patients in CCUs who may or may not even have had a prior diagnosis of diabetes. Too often in response to my questions about an ACS patient’s high blood glucose, our resident will respond, “Oh, I’ve got it covered.” All clinicians need to know is that this is clearly not optimal.

Carl J. Pepine

The American Diabetes Association and American College of Endocrinology recommend a glucose target ≤110 mg/dL for patients in the ICU. Numerous studies have shown that intense glucose control using IV insulin with blood glucose targets of 80 mg/dL to 110 mg/dL improve hospital survival compared with conventional targets with subcutaneous insulin and physician-directed dosing. Van den Berghe et al found that intensive insulin therapy reduced mortality in the surgical ICU from 8% to 4.6% among patients on ventilation.

Additionally, hospital morbidities decrease significantly (eg, sepsis by 46%, acute renal failure requiring dialysis by 41%, transfusions by 50% and polyneuropathy by 44%).

Infusion protocols important

Following that report, a number of studies have shown that IV insulin infusion protocols decrease the time to achieve and maintain blood glucose targets and reduce the occurrences of hypoglycemia compared with the traditional coverage (eg, sliding scale subcutaneous insulin with directed titration).

However, there is no uniform protocol for IV insulin infusions. Wilson and colleagues have identified 12 protocols and reviewed them in detail. While they found variations across protocols, there were major differences in initial and subsequent bolus insulin, staff implementation. Adjustments in infusion rate, time to target glucose levels and insulin recommendations all out perform traditional coverage.

The essentials of these IV insulin infusion protocols are to safely and effectively correct hyperglycemia, adjust the infusion rate to attain and maintain the target blood glucose, correct the infusion rate without under or over compensation, to make infusion adjustments as insulin sensitivity for nutritional status changes, and respond to a rapid fall in blood glucose. Finally, the protocol should be flexible to transition patients smoothly to subcutaneous insulin when appropriate.

The American College of Cardiology/American Heart Association guidelines for patients with NSTEMI and STEMI recommend intense glucose management as a Class I indication. I find that many patients are not receiving intense glucose management.

Physicians need to be aware that under these circumstances, insulin infusion has the potential to save lives and reduce complications. As Lautamäki et al found, the mechanisms are not totally resolved but insulin infusion does have important coronary vascular effects to restore myocardial blood flow.

Despite the epidemic of diabetes, we are not paying enough attention to intense management of hyperglycemia in our patients with acute coronary disease, regardless of whether they had diabetes prior to hospital entry. In fact, some studies suggest that hyperglycemia patients not known to be diabetic prior to hospitalization have worse outcomes compared with hospitalized patients with prior diabetes. All of these patients who are hospitalized with ACS have the potential to benefit from intense glycemic control with IV insulin.

For more information:

• Van den Berghe G, Wouters P, Weekers F, et al. Intensive insulin therapy in critically ill patients. N Engl J Med. 2001;345:1359-1367.
• Wilson M, Weinreb J, Soo Hoo GW. Intensive insulin therapy in critical care. Diabetes Care. 2007;30:1005-1011.
• Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-Elevation myocardial infarction – executive summary: A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (writing committee to revise the 1999 guidelines for the management of patients with acute myocardial infarction). J Am Coll Cardiol. 2004:44:671-719.
• Lautamäki R, Airaksinen KEJ, Seppen M, et al. Insulin improves myocardial blood flow in patients with type 2 diabetes and coronary artery disease. Diabetes. 2006;55:511-516.