External catheters reduce risk of urinary tract infection in men

Jul 3 2006

It's one of the things about a hospital stay that men loathe, and that infectious bacteria love: the urinary catheter. Now, a new study shows that a less-unpleasant option for male hospital patients is also a much safer one.

In fact, men whose urine was collected with an external or "condom" catheter during their hospital stay had an 80 percent reduction in the risk of urinary tract infection (UTI) or death as compared with men whose urine was collected with the usual "indwelling" catheter, the research shows. The condom catheters were also far more likely to be seen as comfortable and non-painful.

In the first-ever randomized, controlled trial comparing the two types of catheters, that striking difference in infection and death risk was seen in men who didn't have dementia and didn't need an indwelling catheter for medical reasons. Other men, and all women, should continue to use indwelling catheters, the researchers say.

But since UTIs are the most common kind of infection to strike patients in the hospital and can lead to fevers and prolonged hospital stays, the results may have tremendous implications, say the researchers from the University of Michigan Health System and the VA hospitals in Seattle and Ann Arbor, Mich. They are publishing their results in the July issue of the Journal of the American Geriatrics Society.

"This is one of the bread-and-butter issues that adversely affects the safety of many hospitalized patients, and that will affect more of us as the population continues to age," says lead author Sanjay Saint, M.D., M.P.H., director of the Patient Safety Enhancement Program and an associate professor of general medicine at the U-M Medical School. "It has implications for many hospitalized patients, 25 percent of whom use catheters, but also for patients in nursing homes and at home."

Saint and his colleagues carried out the trial at the VA Puget Sound Health Care System, where it took several years to find a sufficient number of men willing to be randomly assigned to either type of catheter who also met all of the study's criteria. Saint began the project during his Robert Wood Johnson Clinical Scholars fellowship at the University of Washington, working with senior author Benjamin Lipsky, M.D.

In all, 75 men met the study's enrollment criteria, with 41 receiving an indwelling catheter and the rest receiving one of five sizes of a silicone condom catheter. Their health status was tracked for up to 30 days, including regular testing of their urine for bacteria (a pre-UTI condition called bacteriuria) and monitoring for signs of UTI. The men completed questionnaires about discomfort and other feelings related to their catheter.

The researchers recorded medical and demographic information about the men, and nurses assessed their mental status, looking for signs of dementia or other problems with cognition. The data were analyzed in a way that allowed the researchers to assess the incidence and time until onset of bacteriuria, and a combined measure of bacteriuria, symptomatic UTI, and death, while correcting for the effects of other factors.

The study showed that there were 11 new cases of bacteriuria for every 100 days of hospitalization in patients with indwelling catheters, compared to 6 for those with condom catheters. The indwelling catheter users developed the condition faster, on average within 7 days, compared with 13 days for condom catheter users. The same differences were seen for the combined measure of bacteriuria, symptomatic UTI, or death.

A striking difference emerged when the mental status of the patient was taken into account. For patients without dementia, indwelling catheter users were 4.8 times more likely than condom catheter users to experience bacteriuria, symptomatic UTI, or death. For patients with dementia, this difference was not seen.

The impact of dementia, Saint says, might be linked to the tendency of cognitively impaired men to touch or try to remove their catheters -- which results in the nurse having to clean the area and change the device. This can disturb the bacteria in the area and lead to infection.

In addition to being associated with a lower risk of infection, the condom catheters were much better liked than the indwelling ones, the study showed. Nearly 90 percent of the condom catheter users said the device was comfortable and only 5 percent said they were painful, compared with about 58 percent and 36 percent, respectively, for indwelling catheter users.

The study did not address the cost-effectiveness of using the more expensive condom catheters, which allow for a secure fit, are less likely to fall off than other kinds of condom catheters, and can be used for 48 hours. But Saint suspects that by reducing the incidence of bacteriuria, symptomatic UTI, and death, the extra expense up front will pay for itself in the end. The condom catheters in the study were donated by their manufacturer, Mentor Corporation, along with a research grant to Lipsky, but the company had no role in designing, conducting or analyzing the results of the study.

Already, Saint says, the results of the study have affected his decisions on the inpatient floors of the VA Ann Arbor Healthcare System. "This has changed my own management of patients, to the point where if a patient is cognitively intact, won't remove the catheter, and doesn't have a medical reason for an indwelling catheter, I will choose a condom catheter for him," he says. He notes that patients with urinary tract obstructions, such as prostate problems, cannot use condom catheters. Neither can patients who received certain anesthetics or those in intensive-care units who require close urine monitoring.

The study builds on previous work by Saint and his colleagues that found that silver-coated indwelling catheters were associated with fewer UTIs than conventional indwelling catheters in certain high-risk patients, and that a reminder system for doctors and nurses could reduce the time patients spend with a catheter.

"Sometimes we physicians just order a urinary catheter as a knee-jerk response, instead of thinking through whether the patient needs it," he says. "We should only use catheters when necessary, and even then we should have reminders to prompt discontinuation." Now, with the new results, he hopes that clinicians in hospitals and nursing homes will stop to consider whether a male patient can use a condom catheter rather than an indwelling one. "Even if the infection rate were the same between the two, we should err on the side of giving patients the option they would probably prefer. The only drawback is that we don't yet have an external device for women that works well," he says.