Originally created 08/15/97

Studies say coated catheters effective against bloodstream infections



PHILADELPHIA - Coating catheters with bacteria-fighting substances can help prevent bloodstream infections that kill thousands of Americans annually, researchers say.

Two studies published Friday also conclude that catheters treated with antibiotics or antiseptics could save millions of dollars in hospitalization costs.

Catheters are long, thin, flexible tubes that often are inserted into a blood vessel to deliver food, blood or medicine.

"These infections are potentially serious. Some of them are fatal. We think these are preventable," said Dr. Issam Raad, who led one of the studies published in the Annals of Internal Medicine.

Catheters inserted into large vessels are blamed for 90 percent of bloodstream infections contracted in U.S. hospitals, or more than 200,000 cases a year, Raad said. Past studies have found that 10 percent to 25 percent of the infected patients die.

Although coated catheters cost slightly more than uncoated ones, the two studies agree that the long-run savings could be enormous. A blood infection caused by a catheter can keep a patient in intensive care for nearly seven days, costing nearly $29,000, the studies said.

Both studies were connected to the companies producing the catheters.

The studies tested multilumen central venous catheters, polyurethane tubes with three separate channels. The catheters are usually inserted into the large vein beneath the collarbone. Hospitals use 5 million of the catheters annually, primarily after major operations on seriously ill patients.

"These articles add to the strength of the evidence that's been accumulating," said Dr. Elias Abrutyn, chairman of the department of medicine at Allegheny University of the Health Sciences in Philadelphia. "The implication is, this should work."

But more studies are needed before the principle can be applied to any of the several other types of catheters, cautioned Abrutyn, who co-wrote an accompanying editorial.

One study, paid for by catheter manufacturer Arrow International Inc. of Reading, looked at catheters impregnated with the antiseptics chlorhexidine and silver sulfadiazine.

University of Wisconsin researchers left catheters in 158 patients for an average of six days. The patients with coated catheters were nearly five times less likely to come down with a bloodstream infection.

Seven patients using uncoated catheters became infected, compared with two who used the antiseptic catheters.

In the second study, a group led by Raad and Dr. Rabih Darouiche of the University of Texas M.D. Anderson Cancer Center in Houston found similar results using catheters coated with the antibiotics minocycline and rifampin.

The study, financed by the center's University Cancer Foundation, used catheters supplied by Cook Critical Care of Bloomington, Ind.

Raad and Darouiche, who own a 1993 patent related to Cook's antibiotic coating, tested catheters on 281 patients at five Houston medical centers. The coated devices led to no bloodstream infections, while uncoated catheters caused seven infections, the study said.

Cook's uncoated catheters cost almost $50, and coated ones are about $14 more, Raad said. Arrow's coated catheter costs about $25 more than its uncoated model.