A controlling interest in ICU blood sugars

cap today

March 2006
Feature Story

Anne Paxton

Like many medical advances, tight glycemic control was born from a combination of controlled trials and uncontrolled observations.

The 2001 study by Greet Van den Berghe, et al (Intensive insulin therapy in critically ill patients. N Engl J Med. 2001;345:1359–1367) is the single core study behind tight glycemic control, David Baldwin, MD, of Rush University Medical Center, Chicago, says. Looking at surgery patients in a large ICU, mostly open-heart surgery patients, Van den Berghe randomized their insulin therapy to keep half of them at 110 mg/dL and half at the 160 level, then looked at a variety of markers for the overall success of their treatment.

“She found if they stayed in the ICU less than five days, it didn’t seem to matter whether their sugars were kept normal or not. But about 40 percent of the patients were sicker and ended up staying longer than that. That group, the longerstaying patients, had a dramatic decrease in overall mortality of about 30 percent, and lower chance of kidney failure or infection simply by keeping their blood sugar really normal, super normal.”

No other study had ever looked at this before, Dr. Baldwin notes. But several years earlier a group led by cardiac surgeon Anthony Furnary, MD, of Providence Health System, Portland, Ore., had started exploring ways to control infections in heart surgery patients.

“He was distressed by how often the incisions through the sternum would get infected in patients with diabetes since these are very serious infections. So in 1992 he started a program of treating the problem with insulin.”

The resulting “Portland Protocol” was a finely tuned set of orders for intravenous insulin infusions in hospitalized patients in the ICU and on the wards.

In the process, Providence got the infection rate under control, and there is no difference now between patients with or without diabetes.

According to Providence Health System, Dr. Furnary’s team was “the first to show that hyperglycemia was the significant causal factor for the increased risks of death, infection, and length of hospital stay in the diabetic patient population,” and that the elimination of hyperglycemia with the use of an intravenous insulin infusion for three perioperative days eradicates the incremental increases in these complications that were previously ascribed to the risk factor “diabetes.”

“We know,” Dr. Baldwin says, “that a lot of systems in the body which protect you are paralyzed in many ways by high sugars, so it’s quite important to keep blood sugar under control in the critical two or three days after an operation.” The Portland experience fit very well with the data from the controlled trial in Belgium, he notes.

Another large trial, the DIGAMI study (Diabetes Mellitus, Insulin Glucose Infusion in Acute Myocardial Infarction) was conducted by several cardiologists in England in the 1990s. It showed that using a glucose-insulin infusion to keep blood sugar below 200 during the acute phase reduced mortality over 3.5 years. But flaws in the study’s design and the randomization brought controversy that “distracted a lot of people from the basic message,” Dr. Baldwin says, and led to the study’s results being widely ignored.

The DIGAMI authors took on a second study in hopes of settling the controversies from the first and making a bigger impact, and the results were announced in late 2005. “Unfortunately, the results were exactly the opposite of what people hoped,” Dr. Baldwin says. “It was a completely negative study and showed no difference between the group with no intervention and the group with intensive insulin. But the study had problems, especially that blood glucose wasn’t well controlled by the participating centers.” The cardiologists’ interest in the concept was dampened further, he says.

In the meantime, however, “Lots of other centers, after the Van den Berghe study was published, said, ‘That looks great and let’s start implementing it.’” At Rush, “we used it first in the surgical ICU starting in 2002, and little by little we’ve exported it to the rest of the five ICUs we have throughout our institution.”

To gain the cooperation of surgeons, he focused on convincing them, a few at a time, “to let us diabetes specialists watch over their patients while they’re in the hospital after surgery and take care of their blood sugar issues for them.” Other institutions have employed various strategies, he says, such as a topdown edict from management saying you have to change your management of these patients today at 9 AM, or a sudden order that every patient had to be handled by a diabetes specialist.

Helping raise awareness along the way was the American College of Endocrinology’s Consensus Development Conference on Inpatient Diabetes and Metabolic Control in 2003, which provided the first set of guidelines for tight glycemic control.

“The first time, ever, that the ADA actually had any recommendations for inpatient care was in January 2005, in its annual Standards of Care for Medical Diabetes in America. And now we have a truly national set of guidelines for the standard of care subscribed to by all the mainstream doctors that specialize in caring for diabetes patients.” But it hasn’t translated into a change in all hospitals because change is so labor-intensive. “You have to go change the hearts and minds and cultures in the entire institution,” Dr. Baldwin says.

As a result, he estimates, only five to 10 percent of hospitals in the United States have adopted tight glycemic control. “Most medical schools in the U.S. belong to a collaborative organization called the University HealthSystem Consortium, and in 2005 a joint project was set up to allow interested hospitals to have their diabetes hospital care audited comprehensively to identify weaknesses and areas for improvements.”

About 37 hospitals signed up for the audit, and some of them performed pretty well. “But a lot did relatively poorly, and even many of the ones that did well weren’t exactly stellar.” So, in the adoption of tight glycemic control, “we have a long way to go—even in academic medical centers.”

Anne Paxton is a writer in Seattle.