Critical Care: Sugar Limit Saves Lives

People recovering from surgery in intensive care units face several possible complications, ranging from infection to organ failure. The fact that most patients’ blood-sugar concentration rises after major surgery has been considered among the least of their problems–until now.

Researchers at the Catholic University of Leuven in Belgium decided to test the effects of strictly controlling blood sugar in more than 1,500 people in the surgical intensive care unit (ICU). Most were nondiabetic. The overall death rate among the patients with strictly controlled blood sugar was a third less than that of patients given conventional treatment.

In the study, 765 participants received intensive insulin therapy to keep their blood sugar at about 107 milligrams of glucose per deciliter of blood, a normal concentration in healthy people. The doctors gave the other 783 only enough insulin to keep their blood sugar at concentrations about twice normal, the standard of care in European and most U.S. hospitals.

The intensive insulin control warded off late complications such as bacterial infections in the blood and multiple organ failure, Greet Van den Berghe reported last week in Denver at the annual meeting of the Endocrine Society.

“This is a major advance because it reduces suffering,” she says. It also reduces costs: Fewer complications translate into a need for fewer expensive treatments to keep these people alive, she adds.

William L. Lanier of the Mayo Clinic in Rochester, Minn., says, “This is a very exciting piece of research . . . and will have a dramatic effect on the treatment of ICU patients.” Keeping blood sugar concentrations normal “appears to offer a huge benefit to these [ICU] patients,” he says. Lanier has found that reducing high concentrations of sugar in blood also benefits critically ill patients suffering from stroke.

Most of the patients in the Belgian study were men, and the average age was 62 years. About 13 percent of the patients in each group had diabetes, a disease in which people have difficulty controlling their blood sugar without treatment. All the patients were so sick that while in the ICU, they required mechanical assistance breathing.

While in intensive care, 8.1 percent of patients given standard treatment died, as did 4.6 percent of those whose blood sugar concentrations were carefully controlled. During the patients’ hospital stays, both in and out of the ICU, 10.9 percent of those in the conventionally treated group died, compared with 7.2 percent of people in the group with stricter glucose control.

The difference between treatment results was especially dramatic among those people who stayed in the ICU for 6 days or more, Van den Berghe says. In this group, deaths occurred in the ICU in 20.2 percent of those whose blood sugar concentration was permitted to rise to twice-normal values but in just 10.6 percent of those whose blood sugar was kept near normal concentrations.

“This is very important, and the benefit is startling,” says Henry Kronenberg of Massachusetts General Hospital in Boston. He adds, however, that other researchers should do follow-up studies before ICUs put the findings into widespread use.

Right now, not all ICUs can safely follow the study’s formula for controlling patients’ blood glucose, Kronenberg cautions. This more aggressive use of insulin adds extra steps to the treatment of these critically ill patients, he points out. Also, if ICU personnel don’t monitor patients closely, tighter blood sugar control may lead to some patients suffering potentially fatal low sugar concentrations in the blood.

“Having said that,” Kronenberg concludes, “if these findings hold up, they will change the way people in intensive care units are taken care of around the world.”