Mechanical Reduction of Catheter-Associated Urinary Tract Infection Risk
By Maureen Carignan, RN
Urinary catheterization is a known source of bacterial infections, which in the worst-case scenario can lead to death. Numerous antimicrobial technologies have been utilized to reduce the incidence of such infections, with varying rates of success. Somewhat overlooked is the contribution made by improved mechanical securement of Foley catheters. In fact, preliminary evidence suggests that securement methods, not antimicrobials, may be the most effective solution to urinary tract infection. In addition, clinicians and institutions should note that proper securement has no downside, a claim that cannot always be made for antimicrobial catheter coatings. In sum, while more research is needed, superior securement has shown such impressive potential for reducing catheter-associated urinary tract infection (CAUTI) risk that institutions should make it central to their strategy for addressing the issue.
Dimensions of the CAUTI Problem
Despite modest advances in controlling this problem, CAUTIs remain a frustratingly frequent consequence of urinary catheterization. More than 5 million patients every year will be catheterized in American acute-care hospitals and nursing homes.1 Of those patients catheterized for more than seven days, up to 25 percent will develop a CAUTI.1 Indeed, CAUTIs constitute the most common nosocomial infection, comprising more than 40 percent of all hospital-acquired infections.1
Beyond their ubiquity, CAUTIs are also dangerous and costly. The second most common cause of nosocomial bloodstream infection, they have been shown to nearly triple the risk of death at an institution.2 While these infections do not extend hospitalization in most cases, they add roughly $500 to $1,000 to direct, acute-care hospitalization costs.1 This may seem like a relatively minor amount, but the large number of CAUTI cases multiplies the impact tremendously.
Finally, patients with asymptomatic CAUTIs, who constitute the majority of infected patients, are commonly treated with antimicrobial drugs. While this strategy fights infection, it also selects for drug-resistant pathogens. These bacteria are in turn the source of most nosocomial CAUTIs.1
Besides antimicrobial drugs, numerous antimicrobial practices and technologies have been studied since the mid-1970s. The most effective of these appears to be a silverhydrogel catheter, the Bardex I.C. Foley (Bard Medical, Covington, Ga.). In studies with small sample populations, the Bardex I.C. reduced CAUTIs by 26 percent, without causing antimicrobial resistance.1 While an important development, this technology clearly cannot eliminate a large percentage of CAUTIs.
In small studies, two other medicated catheters both significantly reduced CAUTIs, but the benefit was undercut by the selection of bacteria resistant to the medications used.1
Research has been unable to establish benefit for several other novel technologies, including a sealed junction between the catheter and the collection tubing, and a catheter coated with silver oxide.1 Some other anti-infective practices have also failed to prove their efficacy. Catheters have been soaked in anti-infective solutions and antimicrobial lubricants have been used during insertion. Anti-infective creams and ointments have been applied. Catheterized patients have had their bladders irrigated with antimicrobial solutions, or had anti-infective solutions added to their collection cases. There is logic to each of these ideas, but none of them have demonstrated value.1
The Securement Solution
In contrast to the aforementioned approaches, the effectiveness of one securement technology, StatLock Foley (Venetec International, San Diego, Calif.), may offer dramatic results, according to preliminary research and anecdotal reports. The device consists of a patented, releasable locking mechanism that swivels. The mechanism is affixed to an adhesive foam pad placed on the patients skin. Among the reports of its effectiveness:
- A continuing care facility in Northern California conducted a sixweek clinical trial of StatLock in an attempt to reduce its CAUTI rate. The facilitys CAUTI rate had averaged 3.46 percent in the four months preceding the trial. Administration viewed this as an unacceptably high level, considering that it occurred despite use of the above-mentioned Bardex I.C. Foley catheter. For the six-week trial period, all patients with Foley catheters (23 males and females) had their catheters secured with StatLock. No CAUTIs occurred in the StatLock-secured patients. Following the trial, the facility returned to its original practice of not securing Foley catheters. The CAUTI problem reappeared; for the two-week period after the trial, the rate was 4.93 percent.3
- At the Clark-Morrison Childrens Urological center at UCLA, Foley catheters were secured with tape prior to adoption of StatLock. Staff suspected tape securement was contributing to the centers CAUTI problem because the sticky surfaces of the tape tended to accumulate contaminants that were difficult to remove, exposing patients to infection risk. In addition, tape-secured catheters almost inevitably dislodged, and made it difficult for patients to ambulate after surgery without the catheters pulling on their bladders. StatLock dramatically improved each of these situations. It made it easy to clean catheters and eliminated the problem of tape contamination. Catheter dislodgements ceased, and catheterized patients were able to move more freely because the device was engineered to move with them.4
- These results must be viewed in proper context. The evaluation at the Northern California facility was a preliminary study with a small patient sample. The results at the Clark-Morrison center are anecdotal. While suggestive, these data are not definitive. They point to the need for a prospective, randomized, multi-center trial that would conclusively determine whether a Foley-specific adhesive anchor device could reduce CAUTI risk.
- Given the importance of cost control in todays competitive health marketplace, it would also be helpful to determine the financial benefit, if any, that adequate securement can provide institutions. Again, preliminary data suggests that the impact can be substantial if CAUTIs can be completely or nearly eliminated. Compare the cost of the StatLock device ($2.99) to the cost of treating CAUTIs (see Dimensions of the CAUTI Problem above), and then consider the prevalence of infections. The potential for large savings is obvious.
Other Benefits of Proper Securement
When clinicians consider whether to alter protocols to include Foley catheter securement devices, they should note the additional benefits that these devices can confer. For example, eliminating tape securement helps protect healthcare workers. A study reported in The American Journal of Anesthesiology has established that tearing tape creates microtears in latex gloves.5 Tears expose workers to infection risk.
The StatLock device has also been shown to help prevent Carignans Syndrome, as described by the current author and Linda Nelson, RN, BSN. This dangerous syndrome occurs post-operatively when patients with inadequately secured in-dwelling urinary catheters wake from anesthesia. Traction on the catheter causes the catheter to slip into the bladder neck during surgery, causing extreme pain and agitation, high blood pressure, accelerated heart rate, occasional aberrant heart beats, and aggressive behavior. First identified at Royal Columbian Hospital (New Westminster, British Columbia), the syndrome vanished when staff implemented StatLock in conjunction with hooking the urinary drainage bag to the OR table.6
Finally, the selection of an appropriate, effective device like StatLock avoids the complications caused by less effective or problematic securement methods. Some of the problems of tape securement have already been mentioned. In addition, tape allows painful movements and traction because it deteriorates over the course of just a few hours. Those same movements and tensions can also cause tissue trauma. Finally, tape can cause local skin reactions and is painful to remove. Elderly patients, who comprise by far the greatest proportion of Foley-catheterized patients, are particularly vulnerable to tape-related pain and trauma because of their more fragile tissues.
Other securement devices have been developed, but none has proven adequate and some may themselves be sources of complications. For example, circumferential leg straps and fasteners can essentially act as tourniquets that can restrict venous and lymphatic flow. This means that patients who already suffer from impaired lower-extremity circulation or are at risk of same will be put at further risk if a leg tourniquet is used on them. The literature accompanying the Dale strap acknowledges this, warning Not for use on patients with phlebitis, poor circulation or advanced diabetes.7 Possible complications of constrictive devices such as these include pulmonary embolism and deep venous thrombosis (DVT).
Among other securement options, some devices employ Velcro fasteners in combination with a tape base. However, their superiority to simple adhesive tape has not been proven, and in some areas for instance, adherence and prevention of catheter movement they appear to offer no real benefit over tape.
A Reasonable Approach to Preventing CAUTIs
It is true that the literature has yet to point to a clear protocol for preventing CAUTIs. But that is no reason for inaction. The prevalence and potential dangers of CAUTIs demand that clinicians and institutions take certain appropriate steps now, based on current knowledge. It should be obvious, for example, that because of their complication potential, urinary catheters should only be used when no other alternative exists, and should be removed as soon as they are no longer necessary.
Beyond this, urinary catheters should be secured with a Foley-specific device that has a documented record of successful use. Currently, the StatLock device fits this description, and others may eventually be proven effective. Proper securement for infection control appears to be an issue in any setting where a Foley catheter is used, except where the catheter is used for simple bladder evacuation during surgery and removed immediately after surgery. It cannot responsibly be overlooked.
Using StatLock in combination with an anti-infective catheter such as Bardex I.C. also seems wise in the current environment. Clinicians should monitor the literature to see if future studies confirm the considerable promise of these devices. But they should note that in the meantime, there is no known downside to the above recommendations and tremendous upside if preliminary results are borne out.
Maureen Carignan RN, is senior marketing director, Canada, at Venetec International.