Efficacy of antimicrobial-impregnated bladder catheters in reducing catheter-associated bacteriuria: a prospective, randomized, multicenter clinical trial

Objectives. To examine the efficacy of bladder catheters impregnated with minocycline and rifampin in reducing catheter-associated bacteriuria.Methods. 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 10⁴ colony-forming units per milliliter or greater.Results. 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.Conclusions. Bladder catheters impregnated with minocycline and rifampin significantly reduced the rate of gram-positive catheter-associated bacteriuria up to 2 weeks after catheter insertion.     

Long-term catheter-associated bacteriuria: species at low concentration

Polymicrobial bacteriuria in patients with long-term (greater than or equal to 30 days) indwelling urethral catheters is common and is associated with potentially serious acute and long-term complications. The dynamics of organisms at low concentration (less than 10(5) cfu/mL) in this setting has not been well-characterized; however, in patients with short-term catheters organisms initially present at low concentration (less than 10(5) cfu/mL) usually grow to high concentration (greater than or equal to 10(5) cfu/mL). At the time of catheter replacement for 7 long-term catheterized patients who were not receiving antibiotics, we identified all species at greater than or equal to 10(2) cfu/mL in fresh urine aspirated from the old indwelling catheter and the new sterile replacement catheter and then determined which of these species were present at high concentration two weeks later. A total of thirty-seven species, nineteen at high and eighteen at low concentration were detected in either the old or the new catheters. Eighteen of the nineteen initially detected at high concentration but only one of the eighteen initially detected at low concentration (p less than 0.001) were present at high concentration two weeks later. In patients with long-term indwelling urethral catheters, the number and multiplicity of species causing bacteriuria at low concentration rival that of species at high concentration; however, species at low concentration usually do not grow to high concentration in the presence of other species at high concentration.     

Refinements in the coating of urethral catheters reduces the incidence of catheter-associated bacteriuria. An experimental and clinical study

The tendency to develop bacteriuria during the use of various forms of indwelling catheters was evaluated in a randomized trial in 90 patients. A silver alloy and hydrogel-coated Foley catheter (SHC) was compared to a non-coated catheter (NC) and a catheter coated only with hydrogel (HC). Three patients (10%) with SHC catheters, 10 (33%) patients with HC catheters, and 15 (50%) patients with NC catheters developed bacteriuria (greater than 10(5) organisms/ml). The difference in the rate of bacteriuria after 5 days of catheterization was statistically significant between the SHC catheter and the NC catheter (p less than 0.002). There was no significant difference between the SHC catheter and the HC catheter, nor was there a significant difference between the HC catheter and the NC catheter. The toxic effects, as estimated by the IC50 value, of the urinary catheter material used was elucidated in an experimental fibroblast model. The IC50 value for the NC catheter was 33.9%, HC catheter 72.2% and for the SHC catheter 98.1%.     

Urethral meatal colonization in the pathogenesis of catheter-associated bacteriuria

Urethral meatal colonization with potential urinary tract pathogens was studied before bacteriuria in 31 consecutive acute spinal cord injury patients on an open ward (137 cultures) and 18 renal homotransplant patients in reverse isolation (80 cultures). All patients required indwelling urethral catheterization and no antimicrobials were given. Daily quantitative cultures of the urethral meatus, and bladder and drainage bag urine were obtained. The urethra was the source for 11 of 31 episodes of bacteriuria (35 per cent). Urethral meatal colonization with the organism responsible for bacteriuria, that is Escherichia coli (5 episodes), Staphylococcus aureus (2), Streptococcus faecalis (2) and Staphylococcus epidermidis (2), was persistent and present from 2 to 5 days before bacteriuria. In each ward 81 per cent or more of the cultures obtained on day 1 of catheterization showed no gram-negative colonization. Subsequently, the gram-negative colonization density increased in both groups but the increase was significant (p less than 0.001) only for patients on the open ward. Similar trends were observed for gram-positive colonization. The prevalence of potential pathogens was similar for patients whether or not they suffered bacteriuria. An increased density of bacterial colonization was associated with increased susceptibility to bacteriuria but the specific urethral meatal flora was not always predictive of the species responsible for bacteriuria.     

Central venous dialysis catheters: catheter-associated infection

Tunneled dialysis catheters (TDC) are extensively used for long-term venous hemodialysis access and their use is frequently associated with infectious complications. Catheter-related bacteremia (CRB) is the most common and important infection associated with TDC use and may be caused by a wide variety of Gram-positive or Gram-negative organisms. Prevention of CRB can be difficult despite use of rigorous infection-control techniques for catheter insertion and access. A number of antibacterial catheter-packing solutions hold promise for reduction of CRB. Treatment of CRB with antibiotics alone yields poor results and may increase the risk for other infectious complications, especially endocarditis. In selected cases where initial infection control can be achieved with antibiotics, guidewire exchange of the TDC results in cure rates equivalent to those of TDC removal and subsequent replacement. Dialysis programs should monitor TDC infections with attention to incidence, bacteriology, and outcomes.     

Microbial biofilm formation and catheter-associated bacteriuria in patients with suprapubic catheterisation

Purpose

Catheter-associated bacteriuria (CAB) with transurethral catheters is almost inevitable. Suprapubic catheters (SPCs) are widely considered to decrease the risk of CAB. However, SPCs are implants similarly prone to microbial biofilm formation. The spectrum of colonising pathogens has not been investigated. The aim of this prospective study was: (1) to assess the diversity of microbial suprapubic catheter colonisation (MSPCC), (2) to identify risk factors and (3) to investigate its association with CAB and catheter-associated urinary tract infection (CA-UTI).

Methods

A total of 218 SPCs from 112 patients were studied. Urine specimens were obtained after device replacement or removal. Sonication was performed to dislodge adherent microorganisms. Data of patient sex, age, indwelling time, and underlying disease were recorded.

Results

Sonicate-fluid culture (SFC) detected MSPCC in 95 %. Increasing indwelling time correlated with MSPCC (p < 0.05). Negative SFC was more frequent when antibiotic prophylaxis was applied at time of catheter placement (15 vs. 2 %, p < 0.05). Most commonly isolated were Enterobacteriaceae (45.8 %), followed by Enterococcus spp. (25.7 %) and Pseudomonas aeruginosa (10.3 %). CAB and CA-UTI were observed in 95 and 11 %, respectively.

Conclusions

This study provides the first analysis of MSPCC. Indwelling time increases, whereas antibiotic prophylaxis decreases the risk of MSPCC. The spectrum of pathogens is comparable to the one obtained from urethral catheter biofilms. Urine specimens could not demonstrate the microbial diversity of MSPCC. SPCs are not preferable to urethral catheters to reduce CAB. Whether the risk of CA-UTI could be minimised by SPCs remains to be clarified.     

Effect of silver oxide/trichloroisocyanuric acid antimicrobial urinary drainage system on catheter-associated bacteriuria

We assessed the efficacy of silver oxide coating of the indwelling urethral catheter and catheter adapter, and instillation of trichloroisocyanuric acid into the urinary drainage bag in the prevention of catheter-associated bacteriuria in a prospective and randomized study of 74 patients. Bacteriuria was documented in 29 of the 74 patients (39 per cent). There was a significant difference between the attack rates, with 11 of 41 patients (27 per cent) in the test group and 18 of 33 (55 per cent) in the control group having bacteriuria (p equals 0.02) after a median time to bacteriuria of 36 and 8 days, respectively (p equals 0.01). Urethral meatal colonization was implicated as the source of bladder bacteriuria in 12 of 18 patients (67 per cent) in the control group and 5 of 11 (45 per cent) in the test group. Trichloroisocyanuric acid significantly reduced drainage bag contamination but bag contamination with the same microorganism responsible for bacteriuria preceded infection in only 2 of the 29 patients (7 per cent), 1 in each group. Patients who received systemic antimicrobial agents acquired bacteriuria less frequently than those who did not. The apparent protective effect of systemic antimicrobials was strongest during the first 4 days of catheterization. The data indicate that episodes of bacteriuria arising from the urethral meatus are common among catheterized patients and that the antimicrobial catheter is effective in reducing the incidence of catheter-associated bacteriuria.     

Central venous line sepsis in the intensive care unit A study comparing antibiotic coated catheters with plain catheters

A randomised controlled clinical trial was undertaken to evaluate the efficacy of antibiotic bonded lines in the reduction of central venous catheter infection. One hundred and seventy-six plain and bonded catheters were inserted into one hundred and ten patients in an intensive care unit, many of whom were admitted with evidence of sepsis. The catheters used in the study group, which had been pre-treated by the manufacturers with the cationic surfactant tridodecylmethylammonium chloride, were bonded with vancomycin 1 g made up in 10 ml of water immediately prior to insertion. The catheters used in the control group were neither pre-treated nor bonded with vancomycin. Eighty percent of control group catheters were infected compared with 62% of study catheters (p = 0.01). The most common organism isolated was coagulase negative staphylococcus. We conclude that antibiotic bonding can reduce central venous catheter infection even in a patient population with a high incidence of sepsis.     

Silver coating of urinary catheters prevents adherence and growth of Pseudomonas aeruginosa

Summary Discs of urinary catheter material were exposed to the flow of artificial urine containing cells of Pseudomonas aeruginosa. Within 10 h an adherent biofilm composed of the bacteria and of their exopolysaccharide products had developed on the uncoated catheter material. On the silver-coated catheter material no biofilm of Pseudomonas aeruginosa had developed.     

Use of a chlorhexidine dressing to reduce microbial colonization of epidural catheters

We performed a prospective randomized controlled trial to assess the efficacy of a chlorhexidine dressing in reducing the microbial flora at the insertion site of epidural catheters. These catheters were used for acute pain management and were dressed either by a standardized method or with a CHX/urethane sponge composite. Microbial colonization of the catheter developed in 9 of 31 controls (29.0%) and 1 of 26 (3.8%) catheters with the CHX dressing (P less than 0.05%). The CHX dressing caused no adverse effects. The data suggest that delivery of antiseptic to the catheter wound site reduces catheter colonization with a possible reduction in the risk of epidural catheter-related infection.     

Routine replacement of tunneled,cuffed, hemodialysis catheters eliminates paraspinal/vertebral infections in patients with catheter-associated bacteremia

BACKGROUND: Management of tunneled, cuffed, central venous catheters in hemodialysis (HD) patients with bacteremia remains a challenge. Attempts to salvage the catheter with systemic antibiotics alone have been associated with increased risk of metastatic infectious complications. METHODS: Retrospective case series of patients with infectious complications in a chronic dialysis unit, affiliated with a tertiary care university hospital. RESULTS: Between 1996 and 1999, when we treated HD catheter-associated bacteremia with systemic antibiotics alone, we encountered a clustering of 8 cases of paraspinal/vertebral infections in a population of 162 patients. After changing our protocol, i.e., routine catheter exchange over a guide wire at approximately 48 h, while on systemic antibiotic therapy, we did not encounter any new cases of paraspinal/vertebral infections over a 15-month period. CONCLUSION: Our experience suggests that routine exchange of tunneled, cuffed catheters over a guide wire in HD patients presenting with bacteremia may significantly reduce serious infectious complications, e.g., epidural abscess/vertebral osteomyelitis.     

Resistance of catheters coated with a modified hydrogel to encrustation during an in vitro test

Summary Mid-shaft specimens were cut from latex catheters coated with a modified hydrogel, latex catheters coated with silicone elastomer, and 100% silicone catheters. These specimens were subjected to controlled in vitro encrustation conditions. During a test period of 11 weeks, there was no significant difference in the quantities of encrusting deposits formed on the three materials.     

Hydrophilic-coated catheters for intermittent catheterisation reduce urethral micro trauma: a prospective, randomised, participant-blinded, crossover study of three different types of catheters

OBJECTIVE: To compare two hydrophilic-coated (SpeediCath and LoFric and one uncoated gel-lubricated catheter (InCare Advance Plus) concerning withdrawal friction force and urethral micro trauma. METHODS: 49 healthy male volunteers participated in this prospective, randomised, blinded, crossover study of three different bladder catheters. The withdrawal friction force was measured, and urine analysis of blood, nitrite and leucocytes, microbiological analysis of urine cultures and subjective evaluation of the catheters were performed. RESULTS: 40 participants completed the study and were included in the analysis. SpeediCath exerted a significantly lower mean withdrawal friction force and work than the gel-lubricated uncoated catheter, whereas LoFric exerted a significantly higher mean friction force than both of the other catheters. The hydrophilic catheters caused less microscopic haematuria and less pain than the gel-lubricated uncoated catheter. Furthermore, 93% of the participants preferred the hydrophilic catheters. CONCLUSION: Hydrophilic-coated catheters perform better than uncoated catheters with regard to haematuria and preference. SpeediCath, but not LoFric, exerts less withdrawal friction force than InCare Advance Plus.     

Do anticoagulation with heparin and protamine reversal alter thrombogenicity of coated and noncoated pulmonary artery catheters?

OBJECTIVE: To clarify the role of anticoagulation with heparin and protamine reversal on the effectiveness of heparin bonding or coating of pulmonary artery catheters in preventing thrombus formation in the Rhesus monkey. DESIGN: A controlled, unblinded, open-labeled study. SETTING: A research laboratory at Tulane School of Medicine (New Orleans, LA). PARTICIPANTS: Twenty-four anesthetized Rhesus monkeys. INTERVENTIONS: The monkeys were assigned to one of four groups. In the first group (group A), non-heparin-coated catheters were inserted into a femoral vein through an incision, advanced proximally for a distance of 30 cm, and left in place for 1 hour. In the second group (group B), heparin-coated catheters were placed and evaluated in the same manner as in group A. In the third group (group C), the primates received 3 mg/kg of heparin intravenously (i.v.) before insertion of a non-heparin-coated pulmonary artery catheter. After the catheter had been in place for 1 hour, protamine, 3 mg/kg i.v., was administered, and the catheter was left in place for an additional hour. In the final group (group D), the primates received 3 mg/kg of heparin i.v. before insertion of a heparin-coated pulmonary artery catheter. After the catheter had been in place for 1 hour, protamine, 3 mg/kg i.v., was administered, and the catheter was left in place for an additional hour. In each group, the catheter was withdrawn with the balloon inflated to minimize any stripping of thrombus from the surface of the catheter. Thrombus was removed from the catheter through a femoral vein cutdown and weighed. Laboratory values were determined for each animal, and clot formation was evaluated in each group. After completion of the study, the animals were returned to the primate breeding colony. MEASUREMENTS AND MAIN RESULTS: There were no significant differences in hematocrit, prothrombin time, partial thromboplastin time, or platelet levels among the four groups; therefore, the data were pooled. Clots were observed on five of six catheters in both groups A and C; however, clot formation was seen in one of six catheters in group B and three of six catheters in group D. There was a statistically significant difference (p < 0.01) in mean clot weight in group A (265 +/- 68 mg; range, 0 to 447 mg) compared with 13 +/- 13 mg in group B (range, 0 to 80 mg). There was no significant difference in mean clot weight in group C (104 +/- 35 mg; range, 0 to 202 mg) compared with group D (24 +/- 16 mg, range, 0 to 98 mg). Additionally, in group C, the mean clot weight was significantly less than in group A. CONCLUSION: Anticoagulation of primates with heparin before catheter insertion imparts some protection to non-coated catheters, and protamine reversal of anticoagulation with heparin may partially negate the protective effect seen with heparin-coated pulmonary artery catheters.     

Use of catheters with the AgION antimicrobial system in kidney transplant recipients to reduce infection risk

Microbial blood infection represents a high risk for immuno-suppressed patients. Of all catheter-related infections in the bloodstream, 90% result from the use of central venous catheters, the main cause being microbial colonization at the catheter's insertion point or the catheter hub. Between January 2003 and December 2004, 102 patients received a renal transplant including 57 who received a triple-lumen central venous catheter (CVC) during the procedure. Two catheters were used: a standard polyurethane catheter placed in the jugular veina or the subclavian veina for group I, and polyurethane catheters with the AgION antimicrobial system always placed in the subclavian veina for group II. Care and maintenance of the CVCs was standardized in both groups. After catheter removal, the tips were analyzed microbiologically. Of 57 (43.9%) CVCs, 25 were found to be contaminated. In the first group 24 out of 41 CVCs (58.5%) showed bacterial growth, whereas in group II only one catheter (6.6%) had a biofilm. The most common contaminant (18 out of 25, 72%) was Staphylococcus epidermidis. In group II, two patients had positive blood cultures yet a microbiologically sterile CVC. None of the catheters with the AgION antimicrobial system had to be removed owing to local infection or intolerance. The continuous release of silver ions increases the protection against bacteria and fungi during the entire time of catheterization. Use of catheters with the AgION antimicrobial system lead to a marked reduction in catheter-associated infections of the bloodstream.     

Silver ion doped ceramic nano-powder coated nails prevent infection in open fractures: In vivo study

BackgroundDespite improvement in operative techniques and antibiotic therapy, septic complications still occur in open fractures. We developed silver ion containing ceramic nano powder for implant coating to provide not only biocompatibility but also antibacterial activity to the orthopaedic implants.Questions/purposesWe hypothesised silver ion doped calcium phosphate based ceramic nano-powder coated titanium nails may prevents bacterial colonisation and infection in open fractures as compared with uncoated nails.Methods33 rabbits divided into three groups. In the first group uncoated, in the second group hydroxyapatite coated, and in the third group silver doped hydroxyapatite coated titanium nails were inserted left femurs of animals from knee regions with retrograde fashion. Before implantation of nails 50 μl solution containing 10⁶ CFU/ml methicillin resistance Staphylococcus aureus (MRSA) injected intramedullary canal. Rabbits were monitored for 10 weeks. Blood was taken from rabbits before surgery and on 2nd, 6th and 10th weeks. Blood was analysed for biochemical parameters, blood count, C-reactive protein and silver levels. At the end of the 10 weeks animals were sacrificed and rods were extracted in a sterile fashion. Swab cultures were taken from intramedullary canal. Bacteria on titanium rods were counted. Liver, heart, spleen, kidney and central nervous tissues samples were taken for determining silver levels. Histopathological evaluation of bone surrounding implants was also performed.ResultsNo significant difference was detected between the groups from hematologic, biochemical, and toxicological aspect. Microbiological results showed that less bacterial growth was detected with the use of silver doped ceramic coated implants compared to the other two groups (p = 0.003). Accumulation of silver was not detected. No cellular inflammation was observed around the silver coated prostheses. No toxic effect of silver on bone cells was seen.ConclusionSilver ion doped calcium phosphate based ceramic nano powder coating to orthopaedic implants may prevents bacterial colonisation and infection in open fractures compared with those for implants without any coating.