Critical Care: People recovering from surgery in in-

tensive care units face several possible complications, ranging from infection to organ failure. The fact that most patients’ blood-sugar concentration rises after ma- jor 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 0. Most were non- diabetic. 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 con- centrations about twice normal, the standard of care in European and most US. hospitals.

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

“This is a major advance because it re- duces 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 suffer- ing 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 (see story on page 406). 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 sug- ar concentrations were carefully con- trolled. 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

Sugar Limit Saves Lives in the group with stricter glucose control.

The difference between treatment re- sults 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 per- cent of those whose blood sugar was kept near normal concentrations.

“This is very important, and the bene- fit is startling,” says Henry Kronenberg of Massachusetts General Hospital in Boston. He adds, however, that other r e searchers should do follow-up studies before lCUs put the findings into wide-

spread use. Right now, not all ICUs can safely

follow the study’s formula for controlling patients’ blood glucose, Kronenberg cau- tions. 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 pa- tients closely, tighter blood sugar control may lead to some patients suffering po- tentially fatal low sugar concentrations in the blood.

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

Ozone flares with fireworks festivities Besides decorating the night skies

this Fourth of July, fireworks across the United States will pollute them with ozone, according to a new study.

in the upper atmosphere, where it’s produced natu- rally by ultraviolet 0 radi- ation striking other oxygen molecules (02). Near the ground, ozone is a pollutant that irritates eyes and makes breathing difficult. Its forma tion there generally requires sunlight and nitrogen oxides.

At Jawaharlal Nehru Uni- versity in New Delhi, India, Arun K. Attri and his col- leagues wondered whether the W radiation emitted by the burning metal salts in fireworks and sparklers might trigger ozone-generat- ing reactions in the lower at- mosphere. To find out, the researchers measured atmo- spheric gases before, during, and after the annual Diwali festival of lights.

They found that near- ground ozone increased be tween 8:40 p.m. and 2:30 a.m. on Diwali Night. Further experiments confirmed that sparklers produce ozone in the absence of nitrogen ox- ides or sunlight, the team re- ports in the June 28 NMURE.

The chemical mechanism is probably similar to the one by which W radiation makes ozone in the upper Bursts of ozone may accompany July 4 fireworks atmosphere, says Attri. explosions.

He and his colleagues are now doing more experiments to better understand this reaction and determine just how much ozone fireworks and sparklers

Ozone, or 03, plays a protective role produce. -J C o n a n

404 SCIENCE NEWS, VOL. 159 JUNE 30,2001