***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In order to acquire an overview of the effectiveness of  antimicrobially impregnated catheters  on the prevention of  catheter related bloodstream infections ( CRI )  , we conducted a systematic review concentrating on r and omized controlled trials ( RCTs ) . The analysis end point was CRI ; therefore , studies focussing only on catheter colonization were excluded . We did not consider abstract s for analysis . We identified 24 RCTs investigating the effectiveness of  antimicrobially impregnated catheters .  In addition , we discovered five meta-analyses and four studies investigating cost effectiveness . For the majority of antimicrobially impregnated catheter types only a few studies were available , and not enough to draw conclusions . Therefore , despite a relatively large number of RCTs available , the routine use of antimicrobially impregnated catheters as a measure for CRI prevention remains controversial , with a need for more high quality studies Central venous catheterization represents a significant medical advancement , particularly in the treatment of critical ill . However , there is a high risk of central venous catheters-related infection . A novel antiseptic central venous catheter , made of polyurethane and impregnated with chlorhexidine and silver sulfadiazine , was developed to reduce the risk of catheters-related infection . In this study , we did a r and omized clinical study to determine the efficacy by using antiseptic catheters for the prevention of central venous catheters-related infection in the intensive care units . A total of 204 patients with 235 central venous catheters were studied at the surgical intensive care units at National Taiwan University Hospital between November 1998 and June 1999 . Participants received either a st and ard triple-lumen polyurethane catheter or an antiseptic catheter ( Arrow International , Reading , Pennsylvania , USA ) . Both were indistinguishable from each other . Compared to st and ard polyurethane catheters , antiseptic catheters were less likely to be colonized by microorganisms when they were cultured at the removal ( 8.0 versus 20.0 colonized catheters per 100 catheters ; relative risk 0.34 [ 95 % CI , 0.15 to 0.74 ] ; p<0.01 ) . There was no significant differences between both groups in catheter-related infections ( 0.9 versus 4.9 infections per 100 catheters ; relative risk 0.17 [ 95 % CI , 0.03 to 1.15 ] ; p = 0.07 ) . Gram-positive cocci and fungi were more likely to colonize in the st and ard polyurethane catheters ( p = 0.06 and 0.04 , compared to antiseptic catheters respectively ) . Two of our cases in the control group died directly due to catheter-related c and idemia . No adverse reactions such as hypersensitivity or leukopenia were found in the antiseptic catheter group . Our study showed that central venous catheters with antiseptic coating were safe and had less risk of colonization of bacteria and fungi than st and ard catheters in the critically ill patients PURPOSE To determine whether silver-coated tunneled hemodialysis catheters reduce infection and to determine the frequency of central venous thrombosis and  stenosis  with percutaneous placement of right internal jugular vein dialysis catheters by interventional radiologists . MATERIAL S AND METHODS Ninety-one patients were r and omly assigned to a treatment ( silver-coated catheter ; n = 47 ) or control  ( identical catheter without silver coating ; n = 44 ) arm . Baseline venography was performed . Catheter tips were cultured and venography was repeated at catheter removal . RESULTS Mean duration of catheter placement was 92 days . Infection occurred in 11 patients ( five in the treatment group , six in the control group ) . Tip cultures in 15 patients ( eight treatment , seven control ) were positive without clinical infection . Infection and colonization rates were slightly but not significantly higher in the treatment group than in the control group . Silver-coated catheters in two ( 4 % ) patients were removed due to reaction to the coating . Completion venograms ( n = 72 ) showed new minor abnormalities in four ( 6 % ) patients and major abnormalities ( stenosis , thrombosis ) in three ( 4 % ) patients . Permanent venous abnormalities occurred in two ( 3 % ) patients . CONCLUSION Silver coating does not confer a benefit against clinical infection or colonization . Interventional radiologic placement of tunneled dialysis catheters yields a low frequency of permanent central venous thrombosis and stenosis PURPOSE Percutaneously inserted central venous catheters are widely used . Catheter-related bacteremia or fungemia is the most frequent serious complication of these catheters . In an attempt to reduce the frequency of such infections , a subcutaneous cuff constructed of a biodegradable collagen matrix impregnated with bactericidal silver was developed . Our goal was to assess , in a multicenter clinical trial , the effectiveness of this cuff in preventing catheter-related infection . MATERIAL S AND METHODS Central venous catheters needed for fluid or drug therapy , hemodynamic monitoring , or hyperalimentation in patients in three centers were r and omly assigned to be inserted with or without the cuff .  Patients and catheters in the two groups were comparable in terms of risk factors predisposing to infection , including colonization of skin about the insertion site . RESULTS The results with 234 catheters inserted into a new site showed that catheters inserted with the cuff were threefold less likely to be colonized on removal ( more than 15 colony-forming units ) than were control catheters ( 28.9 percent versus 9.1 percent , p = 0.002 ) and were nearly fourfold less likely to produce bacteremia ( 3.7 percent versus 1.0 percent ) . Adverse effects from the cuff were not seen . The cuff did not confer protection , however against infection with catheters inserted over a guidewire into old sites . Most of the catheter-related infections identified in this study , including four of the six bacteremias , appear to have been caused by microorganisms colonizing skin about the insertion site , affirming the pathogenetic basis for benefit seen with the cuff in this clinical trial ; two may have derived from contamination of the catheter hub . CONCLUSION This novel , silver-impregnated , attachable cuff can substantially reduce the incidence of catheter-related infection with most percutaneously inserted central venous catheters , can extend the time catheters can be left in place safely , and can prove cost-beneficial OBJECTIVE To evaluate the efficacy of triple-lumen central venous catheters coated with a combination product of chlorhexidine and silver sulfadiazine ( CSS ) in reducing the incidence of local catheter infection and catheter-related bacteremia . DESIGN R and omized , controlled trial . SETTING The surgical intensive care units in a university hospital . PATIENTS All patients who needed central venous catheterization were r and omized to receive either an uncoated triple-lumen catheter ( n = 157 ) or a catheter coated with CSS ( n = 151 ) . MAIN OUTCOME MEASURE Catheters were removed when no longer needed or suspected as a cause of infection . The tip and a 5-cm segment of the intradermal portion of the catheter were cultured semiquantitatively . Blood cultures were obtained when clinical ly indicated . The remaining segment of catheters coated with CSS were cut and incubated on an agar plate with strains of Staphylococcus aureus and Enterococcus . Zone of inhibition was determined 24 hours later . Data were analyzed by survival and logistic multivariate regression methods . RESULTS Catheters coated with CSS were effective in reducing the rate of significant bacterial growth on either the tip or intradermal segment ( 40 % ) compared with control catheters ( 52 % ; P = .04 ) . However , there was no difference in the incidence of catheter-related bacteremia ( 3.8 % [ uncoated ] vs 3.3 % [ coated ] ; P = .81 ) . In vitro activity of catheters with CSS against S aureus was evident up to 25 days but activity against Enterococcus dissipated more quickly over time and was absent by day 4 . The most common colonizing organisms were coagulase-negative staphylococcus and enterococcus . Variables that were associated with a significant amount of growth on the tip or intradermal segment were a duration of catheterization of longer than 7 days , jugular insertion site , and the absence of a CSS coating . The use of a guidewire when the catheter was removed was associated with a lower risk of significant bacterial growth . CONCLUSIONS The use of CSS reduces the incidence of significant bacterial growth on either the tip or intradermal segments of coated triple-lumen catheters but has no effect on the incidence of catheter-related bacteremia . In this patient population , catheters coated with CSS provide no additional benefit over uncoated catheters It has been suggested that central venous catheters impregnated with antiseptics such as chlohexidine and silver-sulfadiazine reduce the risk of catheter-related bacteraemia in intensive care patients . Patients suffering from haematologic malignancy treated by chemotherapy through a central venous catheter are at even greater risk of catheter-related bacteraemia . A prospect i ve double-blind r and omized controlled trial was performed in order to investigate the effectiveness of chlorhexidine and silver-sulfadiazine impregnated catheters ( CH-SS ) in these patients . A total of 680 catheters ( 13,826 catheter days ) were inserted , of which 338 were antiseptic impregnated .  Bloodstream infection was observed in 105 cases with an overall risk of 7.6 per 1000 catheter days . Thirty-two infections ( 30.5 % ) were catheter-related , corresponding to a risk of 2.3 per 1000 catheter days . There was no statistically significant different between the overall rates of bloodstream infection for impregnated and non-impregnated catheters ( 14.5 vs. 16.3 % ) . The incidence of catheter-related infection was also similar in both groups ( 5 vs. 4.4 % ) and there was no difference in the time of the onset of bacteraemia in the two groups . It is concluded that the use of CH-SS catheters in patients with haematologic malignancy reduces neither the overall risk of bloodstream infection , nor the catheter-related infection rate , nor the delay for the occurrence of infection OBJECTIVE To evaluate in vitro and in vivo the efficacy of covalent end point-attached heparin to single-lumen polyurethane central venous catheters in reducing microbial adherence and colonization . DESIGN In vitro study : A controlled bench study . In vivo study : A prospect i ve , r and omized , double-blind , clinical trial . SETTING Intensive care unit in a 1200-bed teaching hospital . INTERVENTIONS In vitro study : Adhesion of 17 radiolabeled clinical isolates of Staphylococci to catheters was examined in vitro . In vivo study : The outcome of  heparinized and control catheters was compared in vivo in patients receiving long-term parenteral nutrition . Fifty-five adult patients were prospect ively , blindly r and omized to heparinized or control central venous catheters . The catheters , removed on clinical grounds , were analyzed with semiquantitative and quantitative cultures . Blood cultures were done at catheter removal . MEASUREMENTS AND MAIN RESULTS In vitro study : Coagulase-negative Staphylococci adhered less in vitro to heparinized catheters than to control catheters ( p < .05 ) . In vivo study : Among 32 central venous catheters , or patients who completed the study , catheter-associated bacteremia or fungemia was observed in five patients in the control group ( n = 19 ) and in no patient with a heparinized catheter ( n = 13 ) ( p = .047 ) . Four of 13 catheters in the heparin group were colonized compared with 14 of 19 in the control group ( p = .03 ) . Coagulase-negative Staphylococci were the most frequent microorganisms in both groups . The numbers of organisms found on colonized catheters were larger in the control group than in the heparin group . CONCLUSIONS Covalent end point surface heparinization appears to have a great impact on both in vitro and in vivo bacterial colonization of central venous catheters . Such heparinization can be a practical and economical approach to the prevention of catheter-associated bacteremia or fungemia OBJECTIVE To determine the efficacy of antiseptic compared with st and ard triple lumen central venous catheters ( CVCs ) in reducing the incidence of catheter sepsis and catheter site infection in patients with CVCs for total parenteral nutrition . DESIGN A prospect i ve , r and omized , controlled trial . SETTING Truman Medical Center , the public teaching hospital for University of Missouri , Kansas City , School of Medicine . PATIENTS Seventy-two in patients on the Metabolic Support Service received a CVC for the infusion of total parenteral nutrition . Diagnoses included pancreatic disease , cancer , bowel obstruction , and intestinal surgery , among others . Patients who had a higher risk for contamination during insertion , such as those with a catheter placed through an introducer , inserted in the emergency department , or changed over a 
    Output:
    
Results subgrouped by the different types of anti-infective treatments generally demonstrated treatment effects favoring the treated catheters .
Sensitivity analyses investigating the effects of method ologic differences showed no differences to the overall conclusions of the primary analysis .
AI-CVCs appear to be effective in reducing CRBSI compared with st and ard CVCs .