Hydrogel/silver ion-coated urinary catheter reduces nosocomial urinary tract infection rates in intensive care unit patients: a multicenter study

A comprehensive status update on modification of foley catheter to combat catheter-associated urinary tract infections and microbial biofilms

Present-day healthcare employs several types of invasive devices, including urinary catheters, to improve medical wellness, the clinical outcome of disease, and the quality of patient life. Among urinary catheters, the Foley catheter is most commonly used in patients for bladder drainage and collection of urine. Although such devices are very useful for patients who cannot empty their bladder for various reasons, they also expose patients to catheter-associated urinary tract infections (CAUTIs). Catheter provides an ideal surface for bacterial colonization and biofilm formation, resulting in persistent bacterial infection and severe complications. Hence, rigorous efforts have been made to develop catheters that harbour antimicrobial and anti-fouling properties to resist colonization by bacterial pathogens. In this regard, catheter modification by surface functionalization, impregnation, blending, or coating with antibiotics, bioactive compounds, and nanoformulations have proved to be effective in controlling biofilm formation. This review attempts to illustrate the complications associated with indwelling Foley catheters, primarily focussing on challenges in fighting CAUTI, catheter colonization, and biofilm formation. In this review, we also collate scientific literature on catheter modification using antibiotics, plant bioactive components, bacteriophages, nanoparticles, and studies demonstrating their efficacy through in vitro and in vivo testing.

Bifunctional electrospun poly (L-lactic acid) membranes incorporating black phosphorus nanosheets and nano-zinc oxide for enhanced biocompatibility and antibacterial properties in catheter materials

For several decades, urinary tract infections caused by catheter-associated devices have negatively impacted not only medical device utilization, but also patient health. As such, the creation of catheter materials with both superior biocompatibility and antibacterial properties has become necessary. This study aimed to produce electrospun membranes based on polylactic acid (PLA) with the incorporation of black phosphorus nanosheets (BPNS) and nano-zinc oxide (nZnO) particles, as well as a mixture of both, in order to design bifunctional membranes with enhanced bioactivity and antibacterial features. The optimum spinning process was determined through examination of various PLA mass concentrations, spinning solution propelling speeds, and receiving drum rotating speeds, with emphasis on the mechanical properties of PLA membranes. Additionally, the antibacterial properties and cytocompatibility of the ZnO-BP/PLA antibacterial membranes were explored. Results demonstrated that the ZnO-BP/PLA antibacterial membranes displayed a rich porous structure, with uniform distribution of nZnO particles and BPNS. With the increase of polylactic acid concentration and the decrease of spinning solution advancing and drum rotation speeds, the mechanical properties of the fiber membrane were significantly improved. Furthermore, the composite membranes exhibited remarkable photothermal therapy (PTT) capabilities when aided by the synergistic effect of BP nanosheets and ZnO. This was achieved through near-infrared (NIR) irradiation, which not only dissipated the biofilm but also enhanced the release capability of Zn²⁺. Consequently, the composite membrane demonstrated an improved inhibitory effect on both Escherichia coli and Staphylococcus aureus. The results of cytotoxicity and adhesion experiments also indicated good cytocompatibility, with cells growing normally on the surface of the ZnO-BP/PLA antibacterial membrane. Overall, these findings validate the utilization of both BPNS and n-ZnO fillers in the creation of novel bifunctional PLA-based membranes, which possess both biocompatibility and antibacterial properties for interventional catheter materials.

Recent Advances in Antimicrobial Coatings and Material Modification Strategies for Preventing Urinary Catheter-Associated Complications

In recent years, we have witnessed prominent improvements in urinary catheter coatings to tackle the commonly occurring catheter-associated urinary tract infection (CAUTI) in catheterized patients. CAUTIs are claimed to be one of the most frequent nosocomial infections that can lead to various complications, from catheter encrustation to severe septicaemia and pyelonephritis. Besides general prevention hygienic strategies, antimicrobial-coated urinary catheters show great potential in the prevention of urinary catheter-associated complications. The aim of this review is to present and evaluate recent updates on the development of antimicrobial urinary catheters in the context of the aetiology of urinary malfunction. Subsequently, we shed some light on future perspectives of utilizing 3D printing and the surrounding regulatory directions.

Catheter-Associated Urinary Infections and Consequences of Using Coated versus Non-Coated Urethral Catheters-Outcomes of a Systematic Review and Meta-Analysis of Randomized Trials

Coated urethral catheters were introduced in clinical practice to reduce the risk of catheter-acquired urinary tract infection (CAUTI). We aimed to systematically review the incidence of CAUTI and adverse effects in randomized clinical trials of patients requiring indwelling bladder catheterization by comparing coated vs. non-coated catheters. This review was performed according to the 2020 PRISMA framework. The incidence of CAUTI and catheter-related adverse events was evaluated using the Cochran−Mantel−Haenszel method with a random-effects model and reported as the risk ratio (RR), 95% CI, and p-values. Significance was set at p < 0.05 and a 95% CI. Twelve studies including 36,783 patients were included for meta-analysis. There was no significant difference in the CAUTI rate between coated and non-coated catheters (RR 0.87 95% CI 0.75−1.00, p = 0.06). Subgroup analysis demonstrated that the risk of CAUTI was significantly lower in the coated group compared with the non-coated group among patients requiring long-term catheterization (>14 days) (RR 0.82 95% CI 0.68−0.99, p = 0.04). There was no difference between the two groups in the incidence of the need for catheter exchange or the incidence of lower urinary tract symptoms after catheter removal. The benefit of coated catheters in reducing CAUTI risk among patients requiring long-term catheterization should be balanced against the increased direct costs to health care systems when compared to non-coated catheters.

Nanotechnology as a tool to advance research and treatment of non-oncologic urogenital diseases

Nanotechnology represents an expanding area of research and innovation in almost every field of science, including Medicine, where nanomaterial-based products have been developed for diagnostic and therapeutic applications. Because of their small, nanoscale size, these materials exhibit unique physical and chemical properties that differ from those of each component when considered in bulk. In Nanomedicine, there is an increasing interest in harnessing these unique properties to engineer nanocarriers for the delivery of therapeutic agents. Nano-based drug delivery platforms have many advantages over conventional drug administration routes as this technology allows for local and transdermal applications of therapeutics that can bypass the first-pass metabolism, improves drug efficacy through encapsulation of hydrophobic drugs, and allows for a sustained and controlled release of encapsulated agents. In Urology, nano-based drug delivery platforms have been extensively investigated and implemented for cancer treatment. However, there is also great potential for use of nanotechnology to treat non-oncologic urogenital diseases. We provide an update on research that is paving the way for clinical translation of nanotechnology in the areas of erectile dysfunction (ED), overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and catheter-associated urinary tract infections (CAUTIs). Overall, preclinical and clinical studies have proven the utility of nanomaterials both as vehicles for transdermal and intravesical delivery of therapeutic agents and for urinary catheter formulation with antimicrobial agents to treat non-oncologic urogenital diseases. Although clinical translation will be dependent on overcoming regulatory challenges, it is inevitable before there is universal adoption of this technology to treat non-oncologic urogenital diseases.

Efficacy of Noble Metal-alloy Endotracheal Tubes in Ventilator-associated Pneumonia Prevention: a Randomized Clinical Trial

Background:

Endotracheal tube (ETT) is an important risk factor for the development of Ventilator-associated pneumonia (VAP), as it acts as a reservoir for infectious microorganisms and bypasses the host’s defenses. One of the preventive measures for VAP is endotracheal tube composition. It has been reported that biofilm formation is reduced by using ETTs coated with pure silver or silver compounds. However, noble metal-alloy ETTs have not been adequately studied.

Aims:

To evaluate the efficacy of noble metal alloy ETT (coated Bactiguard Infection Protection ETTs) in preventing VAP compared to standard non-coated ETTs in patients requiring ≥ 48 hours of mechanical ventilation and presenting for coma due to drug intoxication.

Study Design:

Randomized controlled study.

Methods:

Participants were randomized using sealed envelopes with a concealed 1:1 allocation to either the intervention group or the control group. The intervention group used a noble metal–alloy ETT, while the control group received standard ETT. The primary outcomes were the incidence of VAP (per ventilated patients) and the duration of mechanical ventilation.

Results:

Initially, a total of 188 patients were assessed for eligibility, and the final allocation group consisted of 180 patients, who were subsequently randomized into the intervention group (n = 97) and control group (n = 83). The incidence of VAP in the intervention and control groups was 27.83% and 43.16% (P = 0.03), and the VAP ratio per 1000 ventilation days was 51.26/1000 and 83.38/1000 (P = 0.01), respectively. The mean durations of mechanical ventilation were 3.2 ± 0.78 in the intervention group and 5.03 ± 1.88 in the control group (P = 0.22). There was no statistically significant difference between groups in terms of mortality and duration of hospital stay.

Conclusion:

Noble metal-alloy ETT reduces the incidence of VAP, ventilation days, and ICU stay for patients in mechanical ventilation.

Soft Magnetostrictive Actuator String with Cellulose Nanofiber Skin

The formation of cellulose nanofibrous skin with a colloidal suspension is challenging due to the diffusion of colloidal particles and bacteria to the bulk and a limited supply of oxygen for bacteria in the liquid culture environment. A composite-actuating string was fabricated with magnetic nanoparticles (MNPs) and Gluconacetobacter xylinus in a solid matrix of hydrophobic microparticles. G. xylinus synthesizes a dense skin layer of cellulose nanofibers enclosing MNPs in the solid matrix to form an actuator string responsive to an external magnetic field. The nanofibrous actuator string is transformable to fit the diverse shapes of tubular structures in cross section due to its softness and plastic deformability, which reduce friction and stress against the walls of organ tissues. The nanofibrous skin string is bendable at an acute angle by magnetic actuation and is applicable as an endoscopic guidewire to reach a target deep inside a model kidney structure.

Novel Hydroxyapatite Whiskers Modified by Silver Ion and Nano Zinc Oxide Used for Bone Defect Repairment

The hydroxyapatite (HA) is widely used as bone tissue repair material. The improvement of the antibacterial performance is an aroused general interest. In the present study, the silver ion and nano-zinc oxide modified hydroxyapatite whiskers (HAw) were successfully prepared. The microstructure and the composition of the modified HAw were analyzed by Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffractometer (XRD). SEM analysis showed that the length of the whiskers was 70–190 μm, and the aspect ratio was 10–60. With the increase of Ag+ content, the length and aspect ratio of the whiskers gradually decreased and incomplete spherical hydroxyapatite appeared. FEEM analysis showed that nano-zinc oxide particles on ZnO/3Ag-HAw surface are evenly distributed; the average particle size is less than 30 nm. XRD analysis showed that after sol-gel and calcination treatment, the nano-zinc oxide phase appeared in the diffraction pattern of ZnO/Ag-HAw. TEM analysis showed that the interplanar spacing of 5Ag-HAw increased slightly. The CCK-8 and cells co-culture assays were used to assess the proliferation and differentiation of MC3T3-E1 cells, respectively. The antibacterial abilities of the modified HAw against E. coli (ATCC25922) and S. aureus (ATCC6538) were investigated. The cell cytotoxicity test showed that the cytotoxicity level was 0, and there was no cytotoxicity. Cell adhesion experiments showed that ZnO/3Ag-HAw has good cell compatibility and biological activity. The modified hawthorn has a bacteriostatic rate of more than 90% and has good bacteriostatic activity.

Effectiveness of silver alloy-coated silicone urinary catheters in patients with acute traumatic cervical spinal cord injury: Results of a quality improvement initiative

Patients with acute traumatic cervical spinal cord injury (ATCSCI) have an increased risk of catheter-associated urinary tract infection (CAUTI). The effectiveness of silver alloy-coated silicone urinary catheters (SACC) in preventing CAUTI in ATCSCI is unknown and was the objective of this study. We performed a quality improvement initiative in an attempt to reduce CAUTI in patients undergoing spine surgery at a single quaternary center. Prior to July 2015, all patients received a latex indwelling catheter (LIC). All patients with ATCSCI with limited hand function (AIS A,B, or C) received a SACC. Incidence of CAUTI, microbiology, duration of infection, antibiotic susceptibility, and catheter-associated adverse events were recorded prospectively. We studied 3081 consecutive patients over the three years, of whom 302 (9.8%) had ATCSCI; 63% of ATCSCI patients were ASIA Impairment Scale (AIS) A or B. The overall rate of CAUTI was 19% (585/3081), and was 38% (116/302) in patients with ATCSCI. Of 178 ATCSCI patients with LIC, 100 (56%) developed a CAUTI compared with 28 of 124 (23%) patients with SACC (p < 0.05). Poly-microbial and gram-positive infection was more common in LIC than in SACC (p < 0.05). Median duration of infection was 9 days in SACC group and 12 days in LIC group (p = 0.08). Resistance to trimethoprim (p < 0.001) and ciprofloxacin (p < 0.05) were more common in LIC group. There was no difference in catheter-associated adverse events or length of stay between the groups. This quality improvement initiative illustrates the effectiveness of antiseptic silver alloy-coated silicone urinary catheters in patients with ATCSCI. In our population, the use of SACC reduces the incidence and the complexity of CAUTI.

Urinary Catheter Coating Modifications: The Race against Catheter-Associated Infections

Urinary catheters are common medical devices, whose main function is to drain the bladder. Although they improve patients’ quality of life, catheter placement predisposes the patient to develop a catheter-associated urinary tract infection (CAUTI). The catheter is used by pathogens as a platform for colonization and biofilm formation, leading to bacteriuria and increasing the risk of developing secondary bloodstream infections. In an effort to prevent microbial colonization, several catheter modifications have been made ranging from introduction of antimicrobial compounds to antifouling coatings. In this review, we discuss the effectiveness of different coatings in preventing catheter colonization in vitro and in vivo, the challenges in fighting CAUTIs, and novel approaches targeting host–catheter–microbe interactions.

Does antimicrobial coating and impregnation of urinary catheters prevent catheter-associated urinary tract infection? A review of clinical and preclinical studies

Introduction: Catheter-associated urinary tract infection (CAUTI) is one of the most common nosocomial infections in hospitals, accounting for 36% of all health care-associated infections. Areas covered: We aimed to address the potential impact of antimicrobial coating of catheter materials for the prevention of CAUTI and to analyze the progress made in this field. We conducted literature searches in the PubMed, Embase, and Cochrane Library databases, and found 578 articles. Data from 60 articles in either the preclinical or clinical stage were analyzed in this expert review. Expert opinion: The literature review revealed many promising methods for preventing CAUTI. Recent studies have suggested the combination of silver-based products and antibiotics, owing to their synergistic effect, to help address the problem of antibiotic resistance. Other coating materials that have been tested include nitric oxide, chlorhexidine, antimicrobial peptides, enzymes, and bacteriophages. Because of heterogeneity among studies, it is difficult to reliably comment on the clinical efficacy of different coating materials. Future research should focus on double-blind randomized clinical trials for evaluating the role of these potential coating agents.

Antibiofilm Nitric Oxide-Releasing Polydopamine Coatings

The growing number of patient morbidity related to nosocomial infections has placed an importance on the development of new antibacterial coatings for medical devices. Here, we utilize the versatile adhesion property of polydopamine (pDA) to design an antibacterial coating that possesses low-fouling and nitric oxide (NO)-releasing capabilities. To demonstrate this, glass substrates were functionalized with pDA via immersion in alkaline aqueous solution containing dopamine, followed by grafting of low-fouling polymer (poly(ethylene glycol) (PEG)) via Michael addition and subsequent formation of N-diazeniumdiolate functionalities (NO precursors) by purging with NO gas. X-ray photoelectron spectroscopy confirmed the successful grafting of PEG and formation of N-diazeniumdiolate on polydopamine-coated substrates. NO release from the coating was observed over 2 days, and NO loading is tunable by the pDA film thickness. The antibacterial efficiency of the coatings was assessed using Gram-negative Pseudomonas aeruginosa (i.e., wild-type PAO1 and multidrug-resistant PA37) and Gram-positive Staphylococcus aureus (ATCC 29213). The NO-releasing PEGylated pDA film inhibited biofilm attachment by 96 and 70% after exposure to bacterial culture solution for 24 and 36 h, respectively. In contrast, films that do not contain NO failed to prevent biofilm formation on the surfaces at these time points. Furthermore, this coating also showed 99.9, 97, and 99% killing efficiencies against surface-attached PAO1, PA37, and S. aureus bacteria. Overall, the combination of low-fouling PEG and antibacterial activity of NO in pDA films makes this coating a potential therapeutic option to inhibit biofilm formation on medical devices.

The attributable cost of catheter-associated urinary tract infections in the United States: A systematic review

BACKGROUND

Catheter-associated urinary tract infections (CAUTIs) are the most common healthcare-acquired condition. The attributable cost of CAUTIs is frequently cited to be approximately $1,000. However, there is a paucity of recent literature that confirms this estimate. The purpose of this study was to perform a systematic review of the literature that estimates the attributable cost of CAUTIs in the United States.

METHODS

A systematic review was conducted using Pubmed. Studies conducted between the years 2000 and 2017, conducted at a facility within the United States, and that used novel patient-level cost data were included. Attributable cost estimates were adjusted for inflation to 2016 U.S. dollars using the medical care component of the Consumer Price Index.

RESULTS

Only 4 articles met our inclusion criteria. Adjusted to 2016 U.S. dollars, the attributable costs of a CAUTI as reported in these studies were: $876 (inpatient cost to the hospital for additional diagnostic tests and medications); $1,764 (inpatient cost to Medicare for non-intensive care unit [ICU] patients); $7,670 (inpatient and outpatient costs to Medicare); $8,398 (inpatient cost to the hospital for pediatric patients); and $10,197 (inpatient cost to Medicare for ICU patients).

CONCLUSIONS

The cost of a CAUTI ranges widely depending on population, patient acuity, and cost perspective. Attributable costs likely exceed $1,000. Additional research is needed to assess the full economic effect of CAUTIs.

Impermeable Robust Hydrogels via Hybrid Lamination

Hydrogels have been proposed for sensing, drug delivery, and soft robotics applications, yet most of these materials suffer from low mechanical robustness and high permeability to small molecules, limiting their widespread use. This study reports a general strategy and versatile method to fabricate robust, highly stretchable, and impermeable hydrogel laminates via hybrid lamination of an elastomer layer bonded between hydrogel layers. By controlling the layers' composition and thickness, it is possible to tune the stiffness of the impermeable hydrogels without sacrificing the stretchability. These hydrogel laminates exhibit ultralow surface coefficients of friction and, unlike common single-material hydrogels, do not allow diffusion of various molecules across the structure due to the presence of the elastomer layer. This feature is then used to release different model drugs and, in a subsequent experiment, to sense different pH conditions on the two sides of the hydrogel laminate. A potential healthcare application is shown using the presented method to coat medical devices (catheter, tubing, and condom) with hydrogel, to allow for drug release and sensing of environmental conditions for gastrointestinal or urinary tract.

The impact of using silver alloy urinary catheters in reducing the incidence of urinary tract infections in the critical care setting

prospective study was undertaken on three critical care units to establish the efficacy of using a silver alloy urinary catheter in reducing the incidence of nosocomial urinary tract infections.

Some 188 patients participated in the evaluation (94 in each group). A urine sample was obtained post insertion and every three days while on the critical care unit to detect bacteriuria. The infection rate was 12.65 in the standard group and 11.32 in the silver alloy group per 1000 catheter days respectively. The mean duration of catheterisation was 16 days (inter-quartile range 13). Gram positive cocci were responsible for 24.5% of the bacteriuria, Gram negatives 64.5% and yeasts accounted for 11%. Based on these results, routine use of silver alloy catheters cannot be justified for all patients, but may be suited to high-risk female patients.

Bactericidal effect on Foley catheters obtained by plasma and silver nitrate treatments

New medical, materials, and surgical procedures keep improving current health-care practices. Many of these innovations involve polymeric devices that must meet certain clinical and cost requirements. Novel antimicrobial technologies and nanotechnologies are being implemented in more applications such as implant interphases, coatings, and others to avoid postoperatory infections. Here we present a novel approach to create antimicrobial surfaces on Foley catheters widely used in hospitals in order to avoid a variety of harms including infection, pain, and trauma. The combination of plasma and silver nitrate wet treatments demonstrates to be a fast, easy, and convenient method for obtaining colonization-resistant catheter surfaces.

Catheter-Associated Urinary Tract Infections in Intensive Care Units Can Be Reduced by Prompting Physicians to Remove Unnecessary Catheters

Objective:

Indwelling urinary catheters are the most common source of infections in intensive care units (ICUs). The aim of this study was to evaluate the efficacy of nurse-generated daily reminders to physicians to remove unnecessary urinary catheters 5 days after insertion.

Design:

A time-sequence nonrandomized intervention study.

Setting:

Adult ICUs (medical, surgical, cardiovascular surgical, neurosurgical, and coronary care) of a tertiary-care university medical center.

Patients:

All patients admitted to the adult ICUs during a 2-year period. The study consisted of a 12-month observational phase (15,960 patient-days) followed by a 12-month intervention phase (15,525 patient-days).

Intervention:

Daily reminders to physicians from the nursing staff to remove unnecessary urinary catheters 5 days after insertion.

Results:

The duration of urinary catheterization was significantly reduced during the intervention phase (from 7.0 ± 1.1 days to 4.6 ± 0.7 days; P < .001). The rate of catheter-associated urinary tract infection (CAUTI) was also significantly reduced (from 11.5 ± 3.1 to 8.3 ± 2.5 patients with CAUTI per 1,000 catheter-days; P = .009). There was a linear relationship between the monthly average duration of catheterization and the rate of CAUTI (r = 0.50; P = .01). The excess monthly cost of antibiotics for CAUTI was reduced by 69% (from $4,021 ± $1,800 to $1,220 ± $941; P = .004).

Conclusion:

This study demonstrated that a simple measure instituted as part of a continuous quality improvement program significantly reduced the duration of urinary catheterization, rate of CAUTI, and additional costs of antibiotics to manage CAUTI.

Estimating the Proportion of Healthcare-Associated Infections That Are Reasonably Preventable and the Related Mortality and Costs

Objective.

To estimate the proportion of healthcare-associated infections (HAIs) in US hospitals that are “reasonably preventable,” along with their related mortality and costs.

Methods.

To estimate preventability of catheter-associated bloodstream infections (CABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), and ventilator-associated pneumonia (VAP), we used a federally sponsored systematic review of interventions to reduce HAIs. Ranges of preventability included the lowest and highest risk reductions reported by US studies of “moderate” to “good” quality published in the last 10 years. We used the most recently published national data to determine the annual incidence of HAIs and associated mortality. To estimate incremental cost of HAIs, we performed a systematic review, which included costs from studies in general US patient populations. To calculate ranges for the annual number of preventable infections and deaths and annual costs, we multiplied our infection, mortality, and cost figures with our ranges of preventability for each HAI.

Results.

AS many as 65%–70% of cases of CABSI and CAUTI and 55% of cases of VAP and SSI may be preventable with current evidence-based strategies. CAUTI may be the most preventable HAI. CABSI has the highest number of preventable deaths, followed by VAP. CABSI also has the highest cost impact; costs due to preventable cases of VAP, CAUTI, and SSI are likely less.

Conclusions.

Our findings suggest that 100% prevention of HAIs may not be attainable with current evidence-based prevention strategies; however, comprehensive implementation of such strategies could prevent hundreds of thousands of HAIs and save tens of thousands of lives and billions of dollars.

Types of indwelling urethral catheters for short-term catheterisation in hospitalised adults

BACKGROUND

Urinary tract infection (UTI) is the most common hospital-acquired infection. The major associated cause is indwelling urethral catheters. Several measures have been introduced to reduce catheter-associated urinary tract infections (CAUTIs). One of these measures is the introduction of specialised urethral catheters that have been designed to reduce the risk of infection. These include antiseptic-coated and antimicrobial-impregnated catheters.

OBJECTIVES

The primary objective of this review was to compare the effectiveness of different types of indwelling urethral catheters in reducing the risk of UTI and to assess their impact on other outcomes in adults who require short-term urethral catheterisation in hospitals.

SEARCH METHODS

We searched the Cochrane Incontinence Group's Specialised Trials Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE in process, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings (searched 9 September 2014). We also examined the bibliographies of relevant articles and contacted catheter manufacturer representatives for trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs comparing types of indwelling urethral catheters for short-term catheterisation in hospitalised adults. 'Short-term' is defined as a duration of catheterisation which is intended to be less than or equal to 14 days.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened abstracts, extracted data and assessed risk of bias of the included trials. Any disagreement was resolved by discussion or consultation with a third party. We processed data as described in the Cochrane Handbook for Systematic Reviews of Interventions. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

Twenty-six trials met the inclusion criteria involving 12,422 hospitalised adults in 25 parallel group trials, and 27,878 adults in one large cluster-randomised cross-over trial. No trials compared one antiseptic catheter versus another, nor an antimicrobial catheter versus another. Antiseptic-coated indwelling urethral catheters versus standard indwelling urethral cathetersThe primary outcome, symptomatic CAUTI was reported in one large trial with a low risk of bias, comparing silver alloy hydrogel-coated latex catheter (antiseptic-coated) against a standard polytetrafluoroethylene (PTFE)-coated latex catheter (control). The trial used a pragmatic, US Centers for Disease Control and Prevention (CDC)-based definition for symptomatic CAUTI. For the comparison between silver alloy-coated catheter versus standard catheter, there was no significant difference in symptomatic CAUTI incidence (RR 0.99, 95% CI 0.85 to 1.16).For secondary outcomes, the included trials reported on two types of antiseptic catheters (coated with either silver oxide or silver alloy). For the outcome of bacteriuria, silver oxide catheters were not associated with any statistically significant reduction (RR 0.90, 95% CI 0.72 to 1.13). These catheters are no longer manufactured. Silver alloy catheters achieved a slight but statistically significant reduction in bacteriuria (RR 0.82, 95% CI 0.73 to 0.92). However, the one large trial with a low risk of bias did not support this finding (RR 0.99, 95% CI 0.85 to 1.16). The randomised cross-over trial of silver alloy catheters versus standard catheters was excluded from the pooled results because data were not available prior to crossover. The results of this trial showed less bacteriuria in the silver alloy catheter group.For the outcome of discomfort whilst the catheter was in-situ, fewer patients with silver alloy catheters complained of discomfort compared with standard catheters (RR 0.84, 95% CI 0.74 to 0.96). Antimicrobial-impregnated indwelling urethral catheters versus standard indwelling urethral cathetersThe primary outcome measure, symptomatic CAUTI was reported in one large trial with a low risk of bias, comparing nitrofurazone-impregnated silicone catheter (antimicrobial-impregnated) against a standard PTFE-coated latex catheter (control). The nitrofurazone catheter achieved a reduction in symptomatic CAUTI incidence which was of borderline statistical significance (RR 0.84, 95% CI 0.71 to 0.99).For secondary outcomes, the included trials reported on two types of antimicrobial catheters (impregnated with either nitrofurazone or minocycline/rifampicin). Antimicrobial-impregnated catheters, compared with standard catheters, were found to lower the rate of bacteriuria in the antimicrobial group for both minocycline and rifampicin (RR 0.36, 95% CI 0.18 to 0.73), and nitrofurazone (RR 0.73, 95% CI 0.64 to 0.85). The minocycline and rifampicin catheter is no longer manufactured.For the outcome of discomfort whilst the catheter was in-situ, more patients with nitrofurazone catheters complained of pain whilst the catheter was in-situ compared with standard catheters (RR 1.26, 95% CI 1.12 to 1.41). For the period after catheter removal, more patients with nitrofurazone catheters complained of pain than standard catheters (RR 1.43, 95% CI 1.30 to 1.57). Antimicrobial-impregnated indwelling urethral catheters versus antiseptic-coated indwelling urethral cathetersOne large trial compared antimicrobial-impregnated (nitrofurazone) catheters versus silver alloy-coated (antiseptic-coated) catheters. The results showed people were less likely to have a symptomatic CAUTI with nitrofurazone-impregnated catheters (228/2153, 10.6%) compared with silver alloy-coated catheters (263/2097, 12.5%), but this was of borderline statistical significance (RR 0.84, 95% CI 0.71 to 1.00). They did, however, have significantly less bacteriuria (RR 0.78, 95% CI 0.67 to 0.91),While the catheter was in-situ (RR 1.50, 95% CI 1.32 to 1.70), and on removal (RR 1.32, 95% CI 1.20 to 1.45), nitrofurazone catheters were associated with more discomfort compared with silver-coated catheters. One type of standard indwelling urethral catheter versus another type of standard indwelling urethral catheterNone of the trials comparing standard catheters versus other types of standard catheters measured symptomatic CAUTI. In terms of reducing bacteriuria, individual trials were too small to show whether one type of standard catheter was superior to another type. For the outcome of urethral reactions, fully siliconised catheters appeared to be superior to latex-based catheters. However, the trials involved small numbers of participants. There were no statistically significant differences between the different catheters for all other outcomes.

AUTHORS' CONCLUSIONS

Silver alloy-coated catheters were not associated with a statistically significant reduction in symptomatic CAUTI, and are considerably more expensive. Nitrofurazone-impregnated catheters reduced the risk of symptomatic CAUTI and bacteriuria, although the magnitude of reduction was low and hence may not be clinically important. However, they are more expensive than standard catheters. They are also more likely to cause discomfort than standard catheters.

Infection control in the intensive care unit

Nosocomial infections are common in many hospital departments, but particularly so on the intensive care unit, where they affect some 20 to 30% of patients. While early diagnosis and appropriate treatment are, of course, important, perhaps the greatest challenge is in the application of techniques to limit the development of such infections. This review will briefly discuss some of the background pathophysiology and epidemiology of nosocomial infection, and then focus on general and infection-specific preventative strategies individually and as part of broader infection-control programs with infection surveillance.

In vitro efficacy of a novel active-release antimicrobial coating to eradicate biofilms of Pseudomonas aeruginosa

Implant-related infections are becoming increasingly difficult to treat due to the formation of biofilms on implant surfaces. This study analyzed the in vitro efficacy of a novel antimicrobial coating against biofilms of Pseudomonas aeruginosa, using a flow cell system. Results indicated that P. aeruginosa biofilms were reduced by greater than 8 log10 units in less than 24 h. Data indicated that this active-release coating may be promising for preventing biofilm implant-related infections.

A scoping review of important urinary catheter induced complications

This study presents a scoping review of the literature on the morbidity and mortality associated with several common complications of urinary catheterization. Data gathered from the open literature were analyzed graphically to gain insights into the most important urinary catheter induced complications. The results reveal that the most significant catheter complications are severe mechanical trauma (perforation, partial urethral damage and urinary leakage), symptomatic bacterial infection, and anaphylaxis, catheter toxicity and hypersensitivity. The data analysis also revealed that the complications with the highest morbidity are all closely related to the mechanical interaction of the catheter with the urethra. This suggests that there is a strong need for urinary catheter design to be improved to minimize mechanical interaction, especially mechanical damage to the urinary tract, and to enhance patient comfort. Several urinary catheter design directions have been proposed based on tribological principles. Among the key recommendations is that catheter manufacturers develop catheter coatings which are both hydrophilic and antibacterial, and which maintain their antibacterial patency for at least 90 days.

Proteolytically activated anti-bacterial hydrogel microspheres

Hydrogels are finding increased clinical utility as advances continue to exploit their favorable material properties. Hydrogels can be adapted for many applications, including surface coatings and drug delivery. Anti-infectious surfaces and delivery systems that actively destroy invading organisms are alternative ways to exploit the favorable material properties offered by hydrogels. Sterilization techniques are commonly employed to ensure the materials are non-infectious upon placement, but sterilization is not absolute and infections are still expected. Natural, anti-bacterial proteins have been discovered which have the potential to act as anti-infectious agents; however, the proteins are toxic and need localized release to have therapeutic efficacy without toxicity. In these studies, we explore the use of the glutathione s-transferase (GST) to anchor the bactericidal peptide, melittin, to the surface of poly(ethylene glycol) diacrylate (PEGDA) hydrogel microspheres. We show that therapeutic levels of protein can be anchored to the surface of the microspheres using the GST anchor. We compared the therapeutic efficacy of recombinant melittin released from PEGDA microspheres to melittin. We found that, when released by an activating enzyme, thrombin, recombinant melittin efficiently inhibits growth of the pathogenic bacterium Streptococcus pyogenes as effectively as melittin created by solid phase peptide synthesis. We conclude that a GST protein anchor can be used to immobilize functional protein to PEGDA microspheres and the protein will remain immobilized under physiological conditions until the protein is enzymatically released.

Prevention and treatment of urinary catheter-associated infections

Catheter-associated urinary tract infections (CA-UTIs) are the most common nosocomial infection worldwide. Prolonged catheterization is the most important risk factor for CA-UTIs. As is the case with all device-related infections, the biofilm plays a central role in the pathogenesis of CA-UTIs. The diagnosis is often difficult, given the lack of good diagnostic tests. The most effective way to prevent infection is to limit catheter use and discontinue the catheter when no longer needed. Catheter removal or exchange is also useful in management. This review summarizes and analyzes the results of published studies of CA-UTIs and assesses the role of prevention approaches and management strategies.

Biocompatibility analysis of an electrically-activated silver-based antibacterial surface system for medical device applications

The costs associated with the treatment of medical device and surgical site infections are a major cause of concern in the global healthcare system. To prevent transmission of such infections, a prophylactic surface system that provides protracted release of antibacterial silver ions using low intensity direct electric current (LIDC; 28 μA system current at 6 V) activation has been recently developed. To ensure the safety for future in vivo studies and potential clinical applications, this study assessed the biocompatibility of the LIDC-activated interdigitated silver electrodes-based surface system; in vitro toxicity to human epidermal keratinocytes, human dermal fibroblasts, and normal human osteoblasts, and antibacterial efficacy against Staphylococcus aureus and Escherichia coli was evaluated. The study concluded that the technological applications of the surface system for medical devices and surgical tools, which contact human tissues for less than 1.5 h, are expected to be self-sterilizing without causing toxicity in vivo.

Use of silver in the prevention and treatment of infections: silver review

BACKGROUND

The use of silver for the treatment of various maladies or to prevent the transmission of infection dates back to at least 4000 b.c.e. Medical applications are documented in the literature throughout the 17th and 18th centuries. The bactericidal activity of silver is well established. Silver nitrate was used topically throughout the 1800 s for the treatment of burns, ulcerations, and infected wounds, and although its use declined after World War II and the advent of antibiotics, Fox revitalized its use in the form of silver sulfadiazine in 1968.

METHOD

Review of the pertinent English-language literature.

RESULTS

Since Fox's work, the use of topical silver to reduce bacterial burden and promote healing has been investigated in the setting of chronic wounds and ulcers, post-operative incision dressings, blood and urinary catheter designs, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. The beneficial effects of silver in reducing or preventing infection have been seen in the topical treatment of burns and chronic wounds and in its use as a coating for many medical devices. However, silver has been unsuccessful in certain applications, such as the Silzone heart valve. In other settings, such as orthopedic hardware coatings, its benefit remains unproved.

CONCLUSION

Silver remains a reasonable addition to the armamentarium against infection and has relatively few side effects. However, one should weigh the benefits of silver-containing products against the known side effects and the other options available for the intended purpose when selecting the most appropriate therapy.

Technologic advances in endotracheal tubes for prevention of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is associated with high morbidity, mortality, and costs. Interventions to prevent VAP are a high priority in the care of critically ill patients requiring mechanical ventilation (MV). Multiple interventions are recommended by evidence-based practice guidelines to prevent VAP, but there is a growing interest in those related to the endotracheal tube (ETT) as the main target linked to VAP. Microaspiration and biofilm formation are the two most important mechanisms implicated in the colonization of the tracheal bronchial tree and the development of VAP. Microaspiration occurs when there is distal migration of microorganisms present in the secretions accumulated above the ETT cuff. Biofilm formation has been described as the development of a network of secretions and attached microorganisms that migrate along the ETT cuff polymer and inside the lumen, facilitating the transfer to the sterile bronchial tree. Therefore, our objective was to review the literature related to recent advances in ETT technologies regarding their impact on the control of microaspiration and biofilm formation in patients on MV, and the subsequent impact on VAP.

Types of indwelling urinary catheters for long-term bladder drainage in adults

BACKGROUND

Prolonged urinary catheterization is common amongst people in long-term care settings and this carries a high risk of developing a catheter-related urinary tract infection and associated complications. A variety of different kinds of urethral catheters are available. Some have been developed specifically to lower the risk of catheter-associated infection, for example antiseptic or antibiotic impregnated catheters. Ease of use, comfort and handling for the caregivers and patients, and cost-effectiveness are also important factors influencing choice.

OBJECTIVES

The primary objective was to determine which type of indwelling urinary catheter is best to use for long-term bladder drainage in adults.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Register (last searched 31 March 2011), which includes searches of CENTRAL, MEDLINE and handsearching of journals and conference proceedings, and the reference lists of relevant articles.

SELECTION CRITERIA

All randomised trials comparing types of indwelling urinary catheters for long-term catheterization in adults. Long-term catheterization was defined as more than 30 days.

DATA COLLECTION AND ANALYSIS

Data extraction has been undertaken by two review authors working independently and simultaneously. Any disagreement has been resolved by a third review author. The included trial data were handled according to the methods of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Three trials were included, involving 102 adults in various settings. Two trials had a parallel group design and one was a randomised cross-over trial.Only two of the six targeted comparisons were assessed by these trials: antiseptic impregnated catheters versus standard catheters (one trial) and one type of standard catheter versus another standard catheter (two trials).The single small cross-over trial was inadequate to assess the value of silver alloy (antiseptic) impregnated catheters. In the two trials comparing different types of standard catheters, estimates of differences were all imprecise because the trials also had small sample sizes; confidence intervals (CI) were too wide to rule out clinically important differences. One trial did suggest, however, that the use of a hydrogel coated latex catheter rather than a silicone catheter may be better tolerated (risk ratio (RR) for need for early removal 0.41, 95% CI 0.22 to 0.77).

AUTHORS' CONCLUSIONS

The updated search could not reveal any additional evidence. Very few trials have compared different types of catheter for long-term bladder drainage. All trials were small and showed methodological weaknesses. Therefore, the evidence was not sufficient as a reliable basis for practical conclusions. Further, better quality trials are needed to address the current lack of evidence in this clinically important area.

In vivo efficacy of a silicone‒cationic steroid antimicrobial coating to prevent implant-related infection

Active release antimicrobial coatings for medical devices have been developed to prevent and treat biofilm implant-related infections. To date, only a handful of coatings have been put into clinical use, with limited success. In this study, a novel antimicrobial compound was incorporated into a silicone (polydimethylsiloxane or PDMS) polymer to develop a novel active release coating that addressed several limitations of current device coatings. The efficacy of this coating was optimized using an in vitro flow cells system, then translated to an animal model of a simulated Type IIIB open fracture wherein well-established biofilms were used as initial inocula. Results indicated that the novel coating was able to prevent infection in 100% (9/9) of animals that were treated with biofilms and the novel coating (treatment group). In contrast, 100% (9/9) of animals that were inoculated with biofilms and not treated with the coating (positive control), did develop infection. Nine animals were used as negative controls, i.e., those that were not treated with biofilms, and showed a rate of infection of 11% (1/9). Eight animals were treated with the novel coating only to determine its effect on host tissue. Results indicated that the novel active release coating may have significant promise for future application to prevent biofilm implant-related infections in patients.

[Urinary tract colonization and infection in critically ill patients]

Urinary tract infections (UTIs) account for 20-50% of all hospital-acquired infections occurring in the intensive care unit (ICU). In some reports UTI was found to be more frequent than hospital-acquired pneumonia and intravascular device bacteremia, with a greater incidence in developing countries. The risk factors associated with the appearance of UTI include the severity of illness at the time of admission to the ICU, female status, prolonged urinary catheterization or a longer ICU stay and poor urinary catheter management - mainly disconnection of the closed system. about the present study offers data on the epidemiology of UTI in the ICU, the identified risk factors, etiology, diagnosis, impact upon morbidity and mortality, and the measures to prevent its appearance.

Silver nanoparticle studded porous polyethylene scaffolds: bacteria struggle to grow on them while mammalian cells thrive

Silver nanoparticle studded scaffolds were prepared by exploiting the Ag(+) ion reducing activity of sophorolipids--a class of 'glycolipids' that cap the ensuing nanoparticles as well. To achieve this, the porous polyethylene scaffolds are subjected to N(2) + H(2) plasma treatment, in the first step. Subsequently the sophorolipids are covalently attached to the amine groups on the polymer surface through simple amide chemistry to yield sophorolipid grafted polymer scaffolds. These are then exposed to Ag(+) ions under appropriate conditions leading to the formation of silver nanoparticles immobilized on the polymer scaffolds. It has been found that while bacteria do not survive on these silver studded scaffolds, CHO-K1 cells thrive on them making them good candidates for tissue engineering and bio-implant applications.

Clinical and cost effectiveness of urethral catheterisation: a review

Reducing the number of catheter-associated urinary tract infections (CAUTI) in the National Health Service (NHS) has the potential for large cost savings. This review identifies factors which affect the incidence rate of CAUTI, as well as the need for further studies investigating cost-effectiveness, particularly in the areas of silver alloy catheters and education.

The role of surfaces in catheter-associated infections

In this critical review the biocidal efficacies of a variety of antimicrobial coatings currently in use for catheter surfaces are discussed to formulate the best strategy for decreasing the risk of catheter-associated infections. The development of new coatings containing antimicrobial chemicals and light-activated antimicrobial agents, and their applicability for use in catheters are summarised (132 references).

The pathogenesis of catheter-associated urinary tract infection

Catheter-associated urinary tract infection (CAUTI) remains one of the most common types of hospital-acquired infections. Further progress in the prevention of CAUTI requires a better understanding of its pathogenesis. Bacteria may enter the bladder through contamination of the tip during insertion with the flora of the distal urethra or from bacteria ascending the outside or the inside of the catheter. Residual urine in the bladder of catheterised patients increases the risk of bacteriuria. During the process of infection, bacteria need first to adhere to the epithelial cells of the urinary tract and/or the surface of the catheter. They will then develop into biofilms on the catheter surface and are resistant to the immune system and antibiotics. Catheters by themselves may cause immediate physical damage to the bladder epithelium; they may be toxic and also cause inflammation. Bacteria can also damage the epithelium and cause inflammation and the combination of both may be synergistic in producing symptoms in the patient. Most episodes of catheter-associated bacteriuria are asymptomatic but it is not known why some patients are symptomatic and others are not. Further research into the pathogenesis of CAUTI needs to be carried out. A suggestion for the prevention of CAUTI is the use of catheters with an additional eye-hole beneath the balloon to prevent residual urine in the bladder or to remove the tip and balloon altogether, with the additional benefit of having no tip to cause damage or inflammation to the bladder epithelium.

SMART approaches for reducing nosocomial infections in the ICU

Nosocomial infections are problematic in the ICU because of their frequency, morbidity, and mortality. The most common ICU infections are pneumonia, bloodstream infection, and urinary tract infection, most of which are device related. Surgical site infection is common in surgical ICUs, and Clostridium difficile-associated diarrhea is occurring with increasing frequency. Prospective observational studies confirm that use of evidence-based guidelines can reduce the rate of these ICU infections, especially when simple tactics are bundled. To increase the likelihood of success, follow the specific, measurable, achievable, relevant, and time bound (SMART) approach. Choose specific objectives that precisely define and quantify desired outcomes, such as reducing the nosocomial ICU infection rate of an institution by 25%. To measure the objective, monitor staff adherence to tactics and infection rates, and provide feedback to ICU staff. Make objectives achievable and relevant by engaging stakeholders in the selection of specific tactics and steps for implementation. Nurses and other stakeholders can best identify the tactics that are achievable within their busy ICUs. Unburden the bedside provider by taking advantage of new technologies that reduce nosocomial infection rates. Objectives should also be relevant to the institution so that administrators provide adequate staffing and other resources. Appoint a team to champion the intervention and collaborate with administrators and ICU staff. Provide ongoing communication to reinforce educational tactics and fine-tune practices over time. Make objectives time bound; set dates for collecting baseline and periodic data, and a completion date for evaluating the success of the intervention.

Adhesion forces between Staphylococcus epidermidis and surfaces bearing self-assembled monolayers in the presence of model proteins

Self-assembled monolayers (SAMs) are being developed into coatings to reduce microbial biofilm formation on biomaterials. To test anti-adhesion properties, SAMs can be easily constructed on gold, and used to represent a coated biomaterial. However, coatings that prevent bacterial adhesion must also resist protein adsorption. We explored the competitive effects of bacteria and protein for adsorption to SAMs, choosing fetal bovine serum (FBS) to represent protein non-specific binding, and fibronectin (FN) to evaluate ligand/receptor binding. Staphylococcus epidermidis were immobilized on an atomic force microscope (AFM) tip and used as a force probe to detect the interaction forces between bacteria and gold-coated SAMs. The SAMs tested were alkanethiol molecules terminating in isophthalic acid (IPA) or isophthalic acid with silver (IAG). While S. epidermidis showed weak interactions with FBS, the bacteria showed strong adhesion with FN, due to ligand/receptor binding. Bacterial retention and viability experiments were correlated with the force measurements. S. epidermidis interacting with IAG SAMs showed a loss of viability, due to the mobility of silver ions. For most substrata, there was a link between high adhesion forces with bacteria and a high percentage of dead cells being retained on that substratum (even in the absence of a specific biocidal effect, such as silver). This may suggest that high adhesion forces can cause stress to the bacteria which contributed to their death. The relationship between highly adhesive SAMs and bacterial inactivation may be useful in future biomaterial design. When evaluating coatings for biomaterials, it is important to consider the interplay between bacteria, proteins, and the coating material.

Types of urethral catheters for management of short-term voiding problems in hospitalised adults

BACKGROUND

Urinary tract infection (UTI) is the most common hospital acquired infection. The major associated cause is indwelling urinary catheters. Currently there are many types of catheters available. A variety of specialised urethral catheters have been designed to reduce the risk of infection. These include antiseptic impregnated catheters and antibiotic impregnated catheters. Other issues that should be considered when choosing a catheter are ease of use, comfort and cost.

OBJECTIVES

The primary objective of this review was to determine the effect of type of indwelling urethral catheter on the risk of urinary tract infection in adults who undergo short-term urinary catheterisation.

SEARCH STRATEGY

We searched the Specialised Trials Register of the Cochrane Incontinence Group (searched 11 September 2007). We also examined the bibliographies of relevant articles and contacted catheter manufacturer representatives for trials.

SELECTION CRITERIA

All randomised and quasi randomised trials comparing types of indwelling urinary catheters for short-term catheterisation in hospitalised adults. Short-term catheterisation was defined as up to and including fourteen days, or other temporary short-term use as defined by the trialists (for example less than 21 days with data time points at 7 day intervals).

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and independently verified by a second reviewer. Disagreements were resolved by discussion. Data were processed as described in the Cochrane Handbook. Where data in trials were not fully reported, clarification was sought directly from the trialists (secondary sources were used to confirm results of one trial).

MAIN RESULTS

Twenty three trials met the inclusion criteria involving 5236 hospitalised adults in 22 parallel group trials and 27,878 adults in one large cluster-randomised cross-over trial. The antiseptic catheters were either impregnated with silver oxide or silver alloy. Silver oxide catheters were not associated with a statistically significant reduction in bacteriuria in short-term catheterised hospitalised adults but the confidence intervals were wide (RR 0.89, 95% CI 0.68 to 1.15) and these catheters are no longer available. Silver alloy catheters were found to significantly reduce the incidence of asymptomatic bacteriuria (RR 0.54, 95% CI 0.43 to 0.67) in hospitalised adults catheterised for less than one week. At greater than one week of catheterisation the risk of asymptomatic bacteriuria was still reduced with the use of silver alloy catheters (RR 0.64, 95% CI 0.51 to 0.80). The randomised cross-over trial of silver alloy catheters versus standard catheters was excluded from the pooled results because data were not available prior to crossover. The results of this trial indicated benefit from the silver alloy catheters and included an economic analysis that indicated cost savings of between 3.3 per cent and 35.5 per cent. Antibiotic impregnated catheters were compared to standard catheters and found to lower the rate of asymptomatic bacteriuria in the antibiotic group at less than one week of catheterisation for both minocycline and rifampicin (RR 0.36, 95% CI 0.18 to 0.73), and nitrofurazone (RR 0.52, 95% CI 0.34 to 0.78). However, at greater than one week the results were not statistically significant. One of 56 men in the antibiotic impregnated group had a symptomatic UTI compared with 6 of 68 who had standard catheters (RR 0.20, 95% CI 0.03 to 1.63). Three trials compared two different types of standard catheters (defined as catheters that are not impregnated with antiseptics or antibiotics) to investigate infection. Individual trials were too small to show whether or not one type of standard catheter reduced the risk of catheter related urinary tract infection compared to another type of standard catheter.

AUTHORS' CONCLUSIONS

The results suggest that the use of silver alloy indwelling catheters for catheterising hospitalised adults short-term reduces the risk of catheter acquired urinary tract infection. Further economic evaluation is required to confirm that the reduction of infection compensates for 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 the data were too few to draw conclusions about those catheterised for longer. There was not enough evidence to suggest whether or not any standard catheter was better than another in terms of reducing the risk of urinary tract infection 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.

Types of indwelling urinary catheters for long-term bladder drainage in adults

BACKGROUND

Prolonged urinary catheterisation is common amongst people in long-term care settings and this carries a high risk of developing a catheter-related urinary tract infection and associated complications. A variety of different kinds of urethral catheters are available. Some have been developed specifically to lower the risk of catheter-associated infection, for example antiseptic or antibiotic impregnated catheters. Ease of use, comfort and handling for the caregivers and patients, and cost-effectiveness are also important factors influencing choice.

OBJECTIVES

The primary objective was to determine which type of in-dwelling urinary catheter is best to use for long-term bladder drainage in adults.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Trials Register (searched 15 December 2004), MEDLINE (January 1950 to February 2005) and CINAHL (January 1982 to February 2005). We also handsearched 28 relevant journals and conference proceedings. We examined the bibliographies of relevant articles and contacted catheter manufacturers, scientific societies and experts for trials.

SELECTION CRITERIA

All randomised trials comparing types of indwelling urinary catheters for long-term catheterisation in adults. Long-term catheterisation was defined as more than 30 days.

DATA COLLECTION AND ANALYSIS

Data extraction has been undertaken by two review authors independently and simultaneously. Any disagreement has been resolved by a third review author. The included trial data were handled according to the description of the Cochrane Collaboration Reviewers' Handbook.

MAIN RESULTS

Three trials were included involving 102 adults in various settings. Two trials had a parallel group design and one was a randomised cross-over trial. Only two of the six targeted comparisons were assessed by these trials: antiseptic impregnated catheters versus standard catheters (one trial) and one type of standard catheter versus another standard catheter (two trials). The single small cross-over trial was inadequate to assess the value of silver alloy (antiseptic) impregnated catheters. In the two trials comparing different types of standard catheters, estimates of differences were all imprecise because the trials also had small sample sizes: confidence intervals were too wide to rule out clinically important differences. One trial did suggest, however, that the use of a hydrogel coated latex catheter rather than a silicone catheter may be better tolerated (RR for need for early removal 0.41, 95% CI 0.22 to 0.77).

AUTHORS' CONCLUSIONS

Very few trials have compared types of catheter for long-term bladder drainage. All were small and showed methodically weaknesses. Therefore, the evidence was not sufficient as a reliable basis for practical conclusions. Further, better quality trials are needed to address the current lack of evidence in this clinically important area.