Antimicrobials: Healthcare's Silver Bullet Against HAIs?

Rupp issues a caveat, however: “Given the right situation, microbes can probably overwhelm any antimicrobial coating on any device,” he says. “In our study we showed that if you changed a catheter over a guide wire and the coated catheter was put into a colonized bed, (the initial catheter was colonized) the coating didn’t protect the patient from colonization of that second catheter. So if you are not using the right precautions in inserting catheters and caring for them, you can overwhelm these protective technologies."

>>Implants

Surgical implants are another category of medical devices being revolutionized through the use of antimicrobial coatings to help prevent surgical site infections. Traditionally, physicians relied upon systemic antibiotic prophylaxis that addressed microorganisms traveling through the bloodstream from a site some distance from the surgical site, as well as from superficial wound infections. More localized applications of antimicrobial agents such as antibiotics or antiseptics can generally offer more concentrated protection in the immediate surgical area or on the surface of the device.

Darouiche (2003) notes, “Compared with the other local antimicrobial approaches, the coating of surgical implants possesses the advantages associated with using an established method of antimicrobial application, knowing the amount of locally available antimicrobial drugs, having a low likelihood of detectable systemic antimicrobial levels, having a relatively persistent local antimicrobial activity lasting from weeks to months, and using a predetermined selection of non-therapeutic drug or drugs of choice. Such potential advantages, coupled with the variable clinical protection afforded by the antimicrobial coating of catheters, have magnified interest in the antimicrobial coating of surgical implants. The objective is to inhibit bacterial colonization of the implant and, it is hoped, to inhibit implant-associated infection. However, the protective efficacy of antimicrobial-coated surgical implants has yet to be demonstrated in a prospective, randomized clinical trial.”

“There has not been much research done in the areas of infections associated with devices other than catheters, such as surgical implants,” says Rabih Darouiche, MD, professor in the Departments of Medicine (Infectious Disease Section) and Physical Medicine and Rehabilitation. He is also founder of the Multidisciplinary Alliance Against Device-Related Infections. “In contrast, there has been much more research done on infections associated with vascular and urinary catheters.” Darouiche adds,”Although infection control measures are the mainstay approach for preventing device-related infection, adherence to such measures is inconsistent. That is why infection control measures need to be complemented with truly protective technology.”