Silver alloy coated catheters reduce catheter-associated bacteriuria. A large randomized clinical trial of a silver-impregnated urinary catheter: lack of efficacy and staphylococcal superinfection. Reduced rates of catheter-associated infection by use of a new silver-impregnated central venous catheter. A randomized crossover study of silver-coated urinary catheters in hospitalized patients. Comparison of silver-impregnated with standard multi-lumen central venous catheters in critically ill patients. Efficacy of antimicrobial-impregnated bladder catheters in reducing catheter-associated bacteriuria: a prospective, randomized, multicenter clinical trial. Randomized multi-centre trial of the effects of a catheter coated with hydrogel and silver salts on the incidence of hospital-acquired urinary tract infections. Prevention of catheter-associated urinary tract infection with a silver oxide-coated urinary catheter: clinical and microbiologic correlates. Prevention of catheter related bloodstream infection by silver iontophoretic central venous catheters: a randomised controlled trial.
The tendency of indwelling catheters to cause urinary tract infection was evaluated in a randomised clinical study of 223 patients. A Foley catheter coated with silver alloy on both inner and outer surfaces was used in 60 patients; 60 others received a Teflonised latex Foley's catheter and the remaining 103 patients were excluded because of antibiotic treatment, diabetes, etc. There was a statistically significant difference in the incidence of catheter-associated bacteriuria (greater than 10(5) organisms/ml) in the 2 groups after 6 days' catheterisation: 6 patients with the silver coated catheter developed bacteriuria compared with 22 who had the Teflonised latex catheter. This suggests that the silver impregnated urethral catheters reduce the incidence of catheter-associated urinary tract infection. The antibacterial activity of silver-containing compounds has recently been employed in constructing medical devices, such as vascular and urinary catheters, that may be effective in blocking infection. The present study was designed to evaluate the efficacy of a silver oxide-coated urinary catheter.
                A total of 1,309 hospitalized patients who required placement of an indwelling urinary catheter for 24 hours or longer were randomly assigned to receive either a silicone catheter coated externally with 5% silver oxide or a standard silicone elastomer-coated latex catheter. Daily catheter-urine specimens were collected aseptically and catheter-care violations were monitored daily for the duration of the catheterization.
                Bacteriuria developed in 85 of 745 patients (11.4%) in the silver-coated catheter group and in 73 of 564 patients (12.9%) in the control group (P = 0.45). In women who did not receive antibiotics, the rates were 29.3% and 30.4%, respectively (P = 0.98). In men who did not receive antibiotics, the rate of bacteriuria was significantly higher with the silver-coated catheter (29.4% compared to 8.3%, respectively, P = 0.02). Staphylococcal species were isolated more often from the silver-coated catheter group than from the control group (25% versus 8% of all isolates, respectively, P = 0.002).
                This study, the largest ever reported evaluating any silver-impregnated device, has not only failed to demonstrate the efficacy of silver in prevention of catheter-associated bacteriuria, as suggested in prior studies, but it has also shown a significantly increased incidence of bacteriuria in male patients and a significantly increased occurrence of staphylococcal bacteriuria. These results suggest the need for caution and for similar large-scale trials before silver-containing compounds are widely used for preventing device-associated infections, both in vascular and urinary catheters. A central venous catheter with a new form of silver impregnation of the internal and external surfaces was investigated for antimicrobial activity and tolerance in patients in a controlled comparative, prospective and randomized clinical study. Commercially available catheters with no antimicrobial activity were used as controls. One hundred sixty-five catheters were included in the final evaluation. All catheters were percutaneously inserted for the first time with a duration of > or = 5 days and a microbiological examination of the catheter tip. Catheter location (> 90% internal jugular vein), mean duration of catheterization (8-9 days), patients' age and diagnosis were comparable in both groups. Silver-impregnated catheter tips showed an incidence of colonization in 14.2/1000 catheter days and control catheters in 22.8/1000 catheter days. This represents a reduction of 37.7%. Catheter-associated infections were diagnosed in the silver group in 5.26/1000 catheter days and 18.34/1000 catheter days in the control group, indicating a reduction rate of 71.3% (P < 0.05, chi 2-test). No complications or side effects were documented in either group. Urinary tract infections (UTIs) account for 30% to 40% of nosocomial infections resulting in morbidity, mortality, and increased length of hospital stay.
                To assess the efficacy of a silver-alloy, hydrogel-coated latex urinary catheter for the prevention of nosocomial catheter-associated UTIs.
                A 12-month randomized crossover trial compared rates of nosocomial catheter-associated UTI in patients with silver-coated and uncoated catheters. A cost analysis was conducted.
                There were 343 infections among 27,878 patients (1.23 infections per 100 patients) during 114,368 patient-days (3.00 infections per 1000 patient-days). The relative risk of infection per 1000 patient-days was 0.79 (95% confidence interval, 0.63-0.99; P =.04) for study wards randomized to silver-coated catheters compared with those randomized to uncoated catheters. Infections occurred in 291 of 11,032 catheters used on study units (2.64 infections per 100 catheters). The relative risk of infection per 100 silver-coated catheters used on study wards compared with uncoated catheters was 0.68 (95% confidence interval, 0.54-0.86; P =.001). Fourteen catheter-associated UTIs (4.1%) were complicated by secondary bloodstream infection. One death appeared related to the secondary infection. Estimated hospital cost savings with the use of the silver-coated catheters ranged from $14,456 to $573,293.
                The risk of infection declined by 21% among study wards randomized to silver-coated catheters and by 32% among patients in whom silver-coated catheters were used on the wards. Use of the more expensive silver-coated catheter appeared to offer cost savings by preventing excess hospital costs from nosocomial UTI associated with catheter use. Arch Intern Med. 2000;160:3294-3298. To evaluate a new silver-impregnated multi-lumen central venous catheter for reducing catheter-related colonization in intensive care patients.
                Multicenter, prospective, randomized, controlled clinical study.
                Ten adult intensive care units (multidisciplinary, medical and surgical, university and nonuniversity hospitals) in eight institutions.
                A total of 577 patients who required 617 multi-lumen central venous catheters between November 2002 and April 2004 were studied.
                Intensive care adult patients requiring multi-lumen central venous catheters expected to remain in place for >or=3 days were randomly assigned to undergo insertion of silver-impregnated catheters (silver group) or standard catheters (standard group). Catheter colonization was defined as the growth of >or=1,000 colony-forming units in culture of the intravascular tip of the catheter by the vortexing method. Diagnosis of catheter-related infection was performed by an independent and blinded expert committee.
                A total of 320 catheters were studied in the silver group and 297 in the standard group. Characteristics of the patients, insertion site, duration of catheterization (median, 11 vs. 10 days), and other risk factors for infection were similar in the two groups. Colonization of the catheter occurred in 47 (14.7%) vs. 36 (12.1%) catheters in the silver and the standard groups (p = .35), for an incidence of 11.2 and 9.4 per 1,000 catheter days, respectively. Catheter-related bloodstream infection was recorded in eight (2.5%) vs. eight (2.7%) catheters in the silver and the standard groups (p = .88), for an incidence of 1.9 and 2.1 per 1,000 catheter days, respectively.
                The use of silver-impregnated multi-lumen catheters in adult intensive care patients is not associated with a lower rate of colonization than the use of standard multi-lumen catheters. To examine the efficacy of bladder catheters impregnated with minocycline and rifampin in reducing catheter-associated bacteriuria.
                A prospective, randomized clinical trial was conducted at five academic medical centers. Patients undergoing radical prostatectomy were randomized to receive intraoperatively either regular silicone bladder catheters (control catheters) or silicone bladder catheters impregnated with minocycline and rifampin (antimicrobial-impregnated catheters). Catheters remained in place for a mean of 2 weeks. Urine cultures were obtained at about 3, 7, and 14 days after catheter insertion. Bacteriuria was defined as the growth of organism(s) in urine at a concentration of 10(4) colony-forming units per milliliter or greater.
                Kaplan-Meier analysis demonstrated that it took significantly longer for patients (n = 56) who received the antimicrobial-impregnated catheters to develop bacteriuria than those (n = 68) who received the control catheters (P = 0.006 by the log-rank test). Patients who received the antimicrobial-impregnated catheters had significantly lower rates of bacteriuria than those in the control group both at day 7 (15.2% versus 39.7%) and at day 14 (58.5% versus 83.5%) after catheter insertion. Patients who received the antimicrobial-impregnated catheters had significantly lower rates of gram-positive bacteriuria than the control group (7.1% versus 38.2%; P <0.001) but similar rates of gram-negative bacteriuria (46.4% versus 47.1%) and candiduria (3.6% versus 2.9%). The antimicrobial-impregnated catheters provided zones of inhibition against Enterococcus faecalis and Escherichia coli, both at baseline and on removal.
                Bladder catheters impregnated with minocycline and rifampin significantly reduced the rate of gram-positive catheter-associated bacteriuria up to 2 weeks after catheter insertion. Catheters coated with hydrogel and silver salts have been proposed to prevent hospital-acquired urinary tract infections (UTI). We carried out a randomized, prospective, double-blind multi-centre trial to compare those catheters with classical urinary tract catheters. We included in the study 199 patients requiring urethral catheterization for more than three days: 109 in group 1 (classical catheter) and 90 in group 2 (catheter coated with hydrogel and silver salts). Urine from the patients was tested for 10 days after the insertion of the catheter (reactive dipsticks each day and diagnostic urinalysis every two days). The UTI associated with catheterization was defined on the basis of bacterial and cytological criteria (>10(5)cfu bacteria per mL and >10 leucocytes per mm(3)). Twenty-two UTIs were recorded: 13 in group 1 and nine in group 2. The cumulative incidence of UTI associated with catheterization was 11.1% overall, 11.9% for group 1 and 10% for group 2; the odds ratio was 0.82 (95% confidence interval: 0.30 to 2. 20); the cumulative incidence for UTI, calculated by the Kaplan-Meier method was 36.3 overall, 35.2 in group 1 and 36.0 in group 2; the overall incidence density was 19 per thousand days of catheterization, 21 in group 1 and 18 in group 2. The differences between the two groups were not significant. Overall, we feel that there is not enough evidence to conclude that catheters coated with silver salts and hydrogel give greater protection than classical catheters and to recommend widespread use.
                Copyright 2000 The Hospital Infection Society. In a prospective clinical trial involving 482 acutely hospitalized patients, the overall incidence of catheter-associated urinary tract infection (UTI; 10%) was similar in recipients of a silver oxide-coated urinary catheter (silver catheter) or a control silicone catheter. However, female sex and absence of antimicrobial use were independently associated with an increased risk of UTI. After stratification for these variables, the silver catheter reduced the incidence of UTI among women not receiving antimicrobial agents (19% for control catheter vs. 0 for silver catheter, P = .04; confidence interval for the difference in incidence, 0.4%-38%) but not in the other subgroups. Gram-positive UTI was associated with absence of antimicrobial use, the control catheter, and catheter care violations. Gram-negative and candidal UTIs were more common after 7 days of catheterization, and candidal UTI was associated with being female and antimicrobial use. These findings demonstrate that several clinical variables influenced the incidence and microbiology of catheter-associated UTI and that the silver catheter appeared to prevent UTI among women not receiving antimicrobials. To evaluate the efficacy of silver iontophoretic central venous catheters in preventing catheter related colonisation and bloodstream infection among high risk patients in a tertiary hospital.
                Patients requiring central venous access for a period greater than seven days were stratified into two groups according to systemic inflammatory response syndrome criteria before being randomly assigned to receive either silver iontophoretic or control catheters. The incidence of catheter colonisation and catheter related bloodstream infection (CRBSI) was recorded.
                Three hundred and four single lumen study catheters were inserted into 268 patients. Total duration of catheterisation was 5449 days (median, 12 days/catheter). Complete data could be evaluated in 270 catheters: 128 silver iontophoretic catheters and 140 untreated catheters. Forty seven silver iontophoretic catheters (36.7%) were colonised compared with 48 control catheters (33.8%). Seven cases (5.5%) of CRBSI occurred in patients who received silver iontophoretic catheters, compared with 11 cases (7.7%) in patients receiving control catheters. There was no significant difference in the incidence of catheter colonisation or CRBSI between silver iontophoretic and control catheters. When the duration of catheter placement was taken into consideration, Kaplan-Meier analysis showed no significant difference in the risk of CRBSI between the silver iontophoretic catheters and the untreated catheters (p = 0.77).
                There was no significant difference in the incidence of catheter colonisation or CRBSI among high risk patients between silver iontophoretic catheters and control catheters. Future prospective, randomised studies with a larger number of catheters are encouraged to confirm or refute these results.
The results suggest that the use of silver alloy indwelling catheters for catheterising hospitalised adults short-term reduces the risk of catheter associated bacteriuria. Further evaluation is required to confirm if the benefits translate clinically to a reduction in symptomatic urinary tract infection risk, and if this is cost effective considering the increased cost of silver alloy catheters. Catheters impregnated with antibiotics are also beneficial in reducing bacteriuria in hospitalised adults catheterised for less than one week but there was insufficient data to draw conclusions about those catheterised for longer. Further studies are required to assess the effects of antibiotic impregnated catheters on the risk of symptomatic urinary tract infection. There was not enough evidence to suggest whether or not any standard catheter was better than another in terms of reducing the risk of bacteriuria in hospitalised adults catheterised short-term. Siliconised catheters may be less likely to cause urethral side effects in men; however, this result should be interpreted with some caution as the trials were small and the outcome definitions and specific catheters compared varied.