CHICAGO (Reuters) - Ventilator tubes treated with silver to reduce infections cut the risk of pneumonia in gravely ill patients by 36 percent compared with similar, untreated tubes, researchers reported on Tuesday.
The findings, published on Tuesday in the Journal of the American Medical Association, suggest the tubes may offer a way to reduce the incidence of this common and often deadly infection, at least for high-risk patients.
Half of the antibiotics used in hospital intensive care units are prescribed to help prevent bacterial pneumonia in patients put on ventilators to help them breathe, according to a commentary in the journal.
Silver is widely used as an antimicrobial agent and has been shown to reduce bacterial pneumonia infections in animals. Medical device maker C.R. Bard funded the study to see if a silver coating would help reduce the infections in humans.
Dr. Marin Kollef of the Washington University School of Medicine in St. Louis and colleagues tested the devices in 1,500 patients expected to be placed on a ventilator for more than 24 hours between 2002 and 2006.
They found ventilator patients given silver-coated breathing tubes had significantly fewer cases of pneumonia than those with untreated ventilator tubes.
Of the 1,509 patients who had tubes in their trachea for 24 hours or longer, 4.8 percent those with silver-coated tubes developed ventilator-associated pneumonia, compared with 7.5 percent of patients with uncoated tubes.
The antimicrobial tubes also delayed the time it took for ventilator-associated pneumonia to develop compared with those using a similar, uncoated tube, the team found.
But the tubes did not reduce death rates, and the findings were limited because many patients could not provide informed consent, reducing the size and overall power of the study, Dr. Jean Chastre of the Groupe Hospitalier Pitie-Salpetriere in Paris, said in a commentary.
Chastre said the findings suggest high-risk patients may benefit from the devices, but said more study is needed before they are recommended for all ventilator patients.
In November, the U.S. Food and Drug Administration gave Bard clearance to market its silver-coated endotracheal tube, known as Agento, but the company said it would wait to launch the product until its study was published in a major journal.
Editing by Maggie Fox