Vascular-access infections in hospitalized patients

Large Bore Catheters with Surface Treatments versus Untreated Catheters for Blood Access

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood contacting catheters. Because these problems are usually related to surface properties of the base catheter material, surface treatment processes, such as ion implantation and ion beam assisted deposition (IBAD) (silver based coatings), can be used to mitigate such complications. Because these ion beam based processes affect only the near-surface region (approximately the outer 1 μm), there is little effect on bulk material properties. This study evaluated silver coated and implanted large bore catheters used for extracorporeal detoxification. In a 186 patient prospective study, 225 large bore catheters were inserted into the internal jugular or subclavian veins. 85 surface treated catheters (Spi-Argent, Spire Corporation, Bedford, MA-USA; n=39 acute catheters, n= 46 long-term catheters) and 28 catheters with surface treatment (Spi-Silicone, Spire Corporation, Bedford, MA-USA) were inserted in 90 patients. 112 untreated catheters placed in 96 patients served as controls (n = 62 acute catheters, n = 58 long-term catheters). After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using a scanning electron microscope (SEM). Bacterial colonization was observed in 8% of the treated catheters compared with 46.4% of untreated catheters. The SEM investigations showed all treated catheters to possess low thrombogenicity. Results of the study indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters.

Understanding biomaterial-tissue interface quality: combined in vitro evaluation

One of the greatest challenges in the development of new medical products and devices remains in providing maximal patient safety, efficacy and suitability for the purpose. A 'good quality' of the tissue-implant interface is one of the most critical factors for the success of the implant integration. In this paper this challenge is being discussed from the point of view of basic stimuli combination to experimental testing. The focus is in particular on bacterial effects on tissue-implant interaction (for different materials). The demonstration of the experimental evaluation of the tissue-implant interface is for dental abutment with mucosal contact. This shows that testing of the interface quality could be the most relevant in controlled conditions, which mimic as possible the clinical applications, but consider variables being under the control of the evaluator.

Antibiotic Releasing Urethane Polymers for Prevention of Catheter Related Infections

In order to improve the resistance of catheters to microbial infections (particularly Staphylococci), a cephalosporin type antibiotic (cefamandole, CEF), and a glycopeptidic antibiotic (vancomycin), were adsorbed onto functionalized polyurethane films. The polymers were characterized by chemical, FT-IR and 'H-NMR analysis. The amounts of antibiotic adsorbed were higher than the ones reported in the literature. The kinetics of release, under standard conditions, was evaluated by in vitro tests; both the adsorption yield and the antibiotic release from the polymer surface depended on the type of the surface-antibiotic interactions. In particular, matrix hydrophilicity, formation of strong ionic bonds, existence of "spacing arms" between antibiotic and matrix bonding site play a role. The antimicrobial activity of the treated films was evaluated by optical microscopy and the Kirby-Bauer test. When exhausted polymer films, previously treated with CEF were submitted to a second adsorption, a superior antibacterial activity was observed.

Risk Factors for Central line associated Bloodstream Infections

OBJECTIVE

To carry out surveillance of central line associated bloodstream infections in a Pediatric intensive care unit (PICU) and determine associated risk factors.

METHODS

This prospective study was conducted over 1.5 years in the PICU. CDC definitions for these infections were followed and associated risk factors were identified.

RESULTS

Of 265 enrolled children with central line, 13 developed blood stream infections (incidence density 5.03/1000 central line days). Significant risk factors included changing the central-line, especially triple lumen, and frequently accessing the central line.

CONCLUSION

Central line associated bloodstream infections are preventable primary bacteremias and intervention strategies for prevention should be based on evidence generated to devise future protocols.

Chylopericardium and chylothorax: unusual mechanical complications of central venous catheters

Obstruction and thrombosis of major systemic veins can occur due to indwelling central venous catheters. If obstruction of the innominate vein or superior vena cava occurs, lymphatic drainage can be impaired due to an increase in pressure in the thoracic duct and lymphatics. We describe a case where superior vena cava syndrome, chylopericardium and chylothorax occurred in a 16-year-old girl due to an indwelling central venous catheter. This was successfully treated with removal of the line, anticoagulation and angioplasty of the innominate vein and superior vena cava.

Surface-Treated versus Untreated Large-Bore Catheters as Vascular Access in Hemodialysis and Apheresis Treatments

Background. Catheter-related infections, thrombosis, and stenosis are among the most frequent complications associated with catheters, which are inserted in vessels. Surface treatment processes of the outer surface, such as ion-beam-assisted deposition, can be used to mitigate such complications. Methods. This retrospective study (1992-2007) evaluated silver-coated (54 patients) and noncoated (105 patients) implanted large-bore catheters used for extracorporeal detoxification. The catheters were inserted into the internal jugular or subclavian veins. After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using scanning electron microscope. Results. The silver coated catheters showed a tendency towards longer in situ time. The microbiologic examinations of the catheter tips were in both catheter types high positive, but not significant. Conclusion. The silver-coated catheters showed no significantly reduction in infection rate by evaluation of all collected data in this retrospective study. There was no association between both catheters in significantly reducing savings in treatment costs and in reducing patient discomfort. Other new developed catheter materials such as the microdomain-structured inner and outer surface are considered more biocompatible because they mimic the structure of natural biological surface.

Clinical characteristics of Stenotrophomonas maltophilia infection in hematopoietic stem cell transplantation recipients: a single center experience

Background

Recipients of hematopoietic stem-cell transplantation (HSCT) are at high risk for infections caused by Stenotrophomonas maltophilia.

Methods

We conducted a retrospective analysis of all infections caused by S. maltophilia in HSCT recipients in a single center in Israel during a 4 year period.

Results

Of 570 patients undergoing HSCT, 19 patients with an invasive S. maltophilia infection were identified. Sixteen had allogeneic HSCT and 3 had autologous HSCT. Seventeen patients (90%) had an indwelling central venous catheter (CVC) at the time of infection. S. maltophilia infections were detected in three clinical settings: as a complication of prolonged neutropenia (n = 9), as a CVC-related non-neutropenic infection occurring after CVC manipulation (n = 8) and as a respiratory tract infection (n = 2). Eleven patients (58%) had a polymicrobial infection. Ten patients (52.6%) received carbapenems during the previous month. The treatment for all patients included broad spectrum antibiotics, which were switched according to susceptibilities upon identification of the isolates. All isolates were susceptible in vitro to TMP-SMX. CVCs were removed in 12 patients (70%). Six patients, all after allogeneic HSCT, died. The CVC was removed in only two of the five patients with CVCs who died.

Conclusions

Stenotrophomonas maltophilia is an emerging nosocomial pathogen in HSCT recipients, both in the early neutropenic phase and in the non-neutropenic phase. It is commonly associated with the presence and manipulation of an indwelling CVC. Removal of the CVC in addition to appropriate antibiotic therapy (TMP-SMX) is crucial for infection control.

Hyphal content determines the compression strength of Candida albicans biofilms

Candida albicans is the most frequently isolated human fungal pathogen among species causing biofilm-related clinical infections. Mechanical properties of Candida biofilms have hitherto been given no attention, despite the fact that mechanical properties are important for selection of treatment or dispersal of biofilm organisms due to a bodily fluid flow. The aim of this study was to identify the factors that determine the compression strength of Candida biofilms. Biofilms of C. albicans wild-type parental strain Caf2-1, mutant strain Chk24 lacking Chk1p [known to be involved in regulation of morphogenesis (yeast-to-hyphae transition)] and gene-reconstructed strain Chk23 were evaluated for their resistance to compression, along with biofilms of Candida tropicalis GB 9/9 and Candida parapsilosis GB 2/8, derived from used voice prosthetic biofilms. Additionally, cell morphologies within the biofilm, cell-surface hydrophobicities and extracellular polymeric substance composition were determined. Our results suggest that the hyphae-to-yeast ratio influences the compression strength of C. albicans biofilms. Biofilms with a hyphal content >50 % possessed significantly higher compressive strength and were more difficult to destroy by vortexing and sonication than biofilms with a lower hyphal content. However, when the amount of extracellular DNA (eDNA) in biofilms of C. albicans Caf2-1 and Chk24 increased, biofilm strength declined, suggesting that eDNA may influence biofilm integrity adversely.

Empiric therapy for intravenous central line infections and nosocomially-acquired acute bacterial endocarditis

Intravascular catheters are essential devices in the intensive care unit, yet catheter-related bloodstream infections (CR-BSI) are associated with increased morbidity and mortality, prolonged hospitalization, and increased medical costs. Management of a CR-BSI requires antibiotics, with or without catheter removal, depending on patient and etiologic factors. Because of the high frequency of staphylococcal infections, it is wise to use a glycopeptide empirically. Extra coverage for Gram-negative bacilli should be administered in severely ill or immunocompromised patients. Once culture and sensitivity results are known, antibiotic therapy can be more selective.

Comparison between qualitative and semiquantitative catheter-tip cultures: laboratory diagnosis of catheter-related infection in newborns

This prospective study evaluated semiquantitative and qualitative catheter-culture methods for diagnosis of catheter-related infection (CRI) in newborns. Catheter tips from newborns admitted to the Neonatal Unit of the University Hospital of the Botucatu Medical School, UNESP were included in the study. Catheter cultures were performed with both semiquantitative and qualitative techniques. For CRI diagnosis, microorganisms isolated from catheter cultures and from peripheral blood cultures were identified and submitted to agent susceptibility test. The gold standard was the certain CRI diagnosis when same microorganism (specie and profile of susceptibility to agents) was isolated from both catheter tips and peripheral blood culture. A total of 85 catheters from 63 newborns were included in the study. The semiquantitative culture method, despite presenting lower sensitivity (90%), showed higher specificity (71%) when compared to 100% of sensitivity and 60% of specificity in the qualitative method. The identification of the microorganisms obtained from the catheter cultures showed a prevalence of coagulase-negative staphylococci (CNS) species. The specie Staphylococcus epidermidis (77.5%) was the prevalent in the catheters with positive semiquantitative cultures. Among 11 episodes with CRI diagnosis, 8 (72.7%) were associated with CNS species, of which 6 were S. epidermidis. Two episodes of CRI by S. aureus and one by Candida parapsilosis were also detected. The semiquantitative catheter-culture method showed advantages for CRI diagnosis in newborns when compared to the conservative qualitative method.

Comparative in vitro efficacies of various catheter lock solutions

MEDTA (minocycline-edetate calcium disodium), taurolidine (2%)-polyvinylpyrolidine (5%) (T/PVP), and ethanol as potential catheter lock solutions have a unique mechanism of action, broad-spectrum activity, and anticoagulant properties. Traditional lock solutions minocycline (M), rifampin (R), ciprofloxacin (C), and vancomycin, except pharmacologic concentrations of C and R and of M and R, were less effective than MEDTA and T/PVP.

Infection control issues in central venous catheter care

Central venous catheters (CVCs) are now a routine part of patient management in the intensive care unit (ICU). Over time, a vast amount of literature associated with the use and care of CVCs has accumulated. The purpose of this article is to discuss the literature associated with the care of these devices in a narrative format. Although particular attention is paid to infection control issues, other fundamental areas such as catheter design, dressings, line changing and post insertion management are also discussed. The article goes on to look at the future of CVC design and concludes with an analysis of future developments related to CVCs.

Complications in large-bore catheters for extracorporeal detoxification methods

Catheters for large vessels have become essential tools for the management of hospitalized or chronically ill patients requiring intensive medical treatments such as extracorporeal detoxification procedures. The increased use of such devices has been accompanied by a corresponding increase in complications, such as infection, sepsis, and thrombosis. In two retrospective studies, the first (1979-1990) with 1672 patients and 2626 large-bore catheters and the second (1996-2001) with 182 patients and 332 acute catheters, the frequency of infections, thrombosis, bleeding, and other side-effects were investigated. All complications and side-effects are presented. In total, the complication rate was in the first study 27.7% (internal jugular vein 23.8% in 2105 catheters, subclavian vein 43.5% in 521 catheters) and in the second study 32.2% (internal jugular vein 20% in 231 catheters, subclavian vein 60.6% in 94 catheters, femoral vein 57.1% in 7 catheters). The majority of complications were puncture not possible, puncture of the artery abscess, septicemia, bleeding, thrombosis, and faults in catheter material. To minimize these complication rates the handling of the inserted catheters before, during, and after the hemodialysis or apheresis treatment is minimized.

Predictive Value of Blood Cultures Positive for Coagulase-Negative Staphylococci: Implications for Patient Care and Health Care Quality Assurance

Interpretation of blood cultures that are positive for coagulase-negative staphylococci (CoNS) is often difficult. Predictive values for blood cultures positive for CoNS in patients with a central vascular line in place were calculated using the following rates: true bacteremia, 3%; blood culture contamination, 2%; detection of bacteremia, 80%; and catheter colonization, 2% (for blood samples obtained through a central vascular line). Positive predictive values were 55% for 1 positive culture result of 1 culture performed, 20% for 1 positive result of 2 performed, and only 5% for 1 positive result of 3 performed. For 2 positive culture results of 2 cultures performed, the positive predictive value was 98% if both samples were obtained through the vein, 96% if one sample was obtained through a catheter and the other was obtained by vein, and only 50% if both samples were obtained through a catheter. Use of this model with institution-specific values for input parameters would assist in clinical decision-making as well as hospital quality assurance.

Long-term catheters for apheresis and dialysis with surface treatment with infection resistance and low thrombogenicity

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood-contacting catheters. These problems are usually related to surface properties of the base catheter material. Surface treatment processes, such as ion implantation and ion beam assisted deposition (IBAD) and microdomain structured surfaces, can be used to mitigate such complications. This study evaluated silver coated and implanted large bore catheters used for extracorporeal detoxification. In a 186 patient prospective study, 225 large bore catheters were inserted into the internal jugular or subclavian veins. Eighty-five surface-treated catheters (Spi-Argent, Spire Corporation, Bedford, MA, USA) and 28 catheters with surface treatment (Spi-Silicone, Spire Corporation) were inserted in 90 patients. One hundred and twelve untreated catheters placed in 96 patients served as controls, After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using a scanning electron microscope (SEM). Bacterial colonization was observed in 8% of the treated catheter compared with 46.4% of untreated catheters. The SEM investigations showed all treated catheters to possess low thrombogenicity. Catheters with microdomain structured surfaces showed same results in preliminary observation. The surface treatments of the large bore catheters can be used to improve thrombus and infection resistance of blood contacting catheters.

Complications of invasive monitoring

Invasive monitoring in anesthesiology is relatively safe. Arterial catheterization in particular has an extremely low rate of serious complications. Radial, brachial, and femoral artery catheterization sites appear to have similar and low complication rates. CVP and PA catheters are more dangerous and entail potentially fatal complications. The most troublesome complication with CVP catheters is perforation of the heart or cava, which should be avoidable under most circumstances if care is taken to position the catheter properly, outside the heart. Chest radiography should be used to specifically ascertain that the catheter is not in a dangerous location. The most troublesome complication with PA catheters is perforation of the pulmonary artery. This is probably a sporadic problem, and it is not necessarily avoidable by adherence to particular techniques. It should be assumed that hemoptysis in a patient with a PA catheter is caused by perforation of the pulmonary artery until proven otherwise, and it should be treated aggressively.

Catheter-related bloodstream infections in HIV-infected patients

Bloodstream infections (BSI) constitute a significant public health problem and represent an important cause of morbidity and mortality in hospitalized patients, with an approximate incidence of one episode per hundred hospital admissions. Studies on BSI in HIV+ patients have identified central venous catheters (CVC) as a risk factor, with an attributable mortality rate of 10-20%. The long-term CVC-related infection risk appeared to be 5 to 10-fold higher with respect to the infection rates among HIV- patients. CVC associated infection rate ranges from 1.3 to 12 infections per 1,000 catheter-days. Staphylococcus aureus is the most common etiologic agent causative of CVC-related BSI, likely the result of the high skin and nasal carriage of this organism among HIV+ patients, mostly intravenous drug users. Coagulase-negative staphylococci are also frequently identified as cause of CVC-related BSI, likely the result of breaches in infection control measures and in antiseptic technique during CVC management. Treating bacteremia without catheter removal would be optimal, but the reported efficacy of systemic antibiotic therapy alone is only 25-32%. Conversely, recent studies have shown that, using an antibiotic-lock procedure, up to 90% of HIV-infected and uninfected patients achieved complete eradication of catheter-related BSIs without catheter removal. Clinical trials using new materials such as covalently linked heparin on the CVC surface, electrically charged CVC, novel topical agents that interfere with bacterial colonization, antiadhesin molecules and agents that block the gene expression involved in the biofilm formation, are all needed to reduce the high catheter-related infection risk among HIV+ patients.

Peripherally inserted central catheters with distal versus proximal valves: prospective randomized trial

PURPOSE

To evaluate whether peripherally inserted central catheters (PICCs) with a proximal valve have any advantage compared to those with a distal valve in regard to the incidence of occlusion, infection, or malfunction.

MATERIALS AND METHODS

One hundred patients (mean age, 46 y) were randomized to receive either a distal-valved Bard Groshong catheter (n = 48) or a proximal-valved Catheter Innovations Pressure Activated Safety Valve catheter (n = 52). All catheters were 4-F, single-lumen PICCs. Catheters were placed under fluoroscopic (n = 82) or sonographic (n = 18) guidance. Most (91%) were placed for the administration of antibiotics. The placement procedure, maintenance, and weekly follow-up were the same for both catheters.

RESULTS

Percutaneous placement with the catheter tip in the central veins was successful in all patients. Mean dwell time was 36 days. There were 12 (25%) occlusive or infectious complications in the distal valve catheter group and six (11.5%) in the proximal valve group (P = .08). There were 25 fractures in 17 distal valve catheters (35.4%) and three (5.8%) proximal valve catheter fractures (P < .01).

CONCLUSION

There was a marked difference in durability between the valved catheters, in favor of the catheter with a proximal valve. There was also a trend for fewer occlusive and infectious complications with the proximal valve catheter.

Sleeve-related thrombosis: a new form of catheter-related thrombosis

In a detailed study of central venous catheter-related sleeve and thrombosis in experimental animals, a new form of thrombosis was detected and termed sleeve-related thrombosis. A silastic catheter was placed in the jugular vein and the anterior vena cava of 22 rabbits and 54 rats. After intervals of 1, 3, 7 days, 2, 3, 4 weeks and 1, 2, 4, 6 months the veins were examined by light microscopy and by transmission electron microscopy. In about 50% of the rats a thrombus was observed at the end of the catheter sleeve. Consecutive cutting allowed the visualization of a transition from a sleeve via part of sleeve and part of thrombus to a pure thrombus. This thrombus was separated from the vein wall and could not be considered a mural thrombus. As the thrombus was only attached to the terminal part of the organized catheter sleeve we propose the name sleeve-related thrombosis.

Surface treated catheters with ion beam based process for blood access

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood contacting catheters. Because these problems are usually related to surface properties of the base catheter material, surface treatment processes such as ion implantation and ion beam assisted deposition (IBAD) (silver based coatings) can be used to mitigate such complications. Because these ion beam based processes affect only the near-surface region (approximately the outer 1 microm), there is little effect on bulk material properties. This study evaluated silver coated large bore catheters used for extracorporeal detoxification. In a 135 patient prospective study, 170 large bore catheters were inserted into the internal jugular or subclavian veins. Seventy-eight surface treated catheters (Spi-Argent, Spire Corporation, Bedford, MA, U.S.A.; n = 32 acute catheters, n = 46 long-term catheters) were inserted in 55 patients. Ninety-two untreated catheters placed in 80 patients served as controls (n = 40 acute catheters, n = 52 long-term catheters). After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using a scanning electron microscope (SEM). Bacterial colonization was observed in 7% of the treated catheters compared with 35.3% of untreated catheters. The SEM investigations showed all treated catheters to possess low thrombogenicity. Results of the study indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters.

Bacteremia associated with central venous catheter infection is not an independent predictor of outcomes

BACKGROUND

Infection is the leading complication of central venous catheters. In the setting of suspected line infection, the CDC recognizes only catheter-related bloodstream infection but not catheter infection without bacteremia, which is designated "colonization." To evaluate the hypothesis that catheter-related bloodstream infection has worse outcomes than catheter infection without bacteremia, we compared demographics, clinical data, and outcomes.

STUDY DESIGN

Analysis of catheter infections was performed on data collected prospectively for all episodes of infection occurring from December 1996 to September 1999 on the surgical services at a university hospital. Catheter tips were cultured only when infection was suspected. Catheter infection without bacteremia was defined as systemic evidence of infection, the presence of at least 15 colony-forming units on the catheter tip by a semiquantitative technique, and absence of bloodstream infection with the same organism as the catheter. Catheter-related bloodstream infection required the presence of bacteremia with the same organism as the catheter tip.

RESULTS

The 59 patients with catheter-related bloodstream infection had more coexistent infections than the 91 patients with catheter infection without bacteremia (2.9+/-0.1 versus 1.7+/-0.1; p=0.0001), most commonly pneumonia (37.3% versus 16.5%, p = 0.004) and urinary tract infections (28.8% versus 8.8%, p = 0.001). Catheter-related bloodstream infection was associated with an increased proportion of gram-negative organisms compared with catheter infections without bacteremia (29.5% versus 16.9%, p = 0.04) and a trend toward fewer gram-positive organisms (61.5% versus 73.7%, p = 0.07). There were no differences in APACHE II score, WBC, length of hospital stay, time from admission to fever, time from fever to treatment, normalization of WBC, days of antibiotics, defervescence, gender, presence of comorbidities, occurrence of colonization while in an ICU, or mortality rate (18.6% with bacteremia, 24.2% without; p = 0.42).

CONCLUSIONS

The presence of bloodstream infection in addition to catheter infection does not appear to alter outcomes. The definition of catheter infection perhaps should be extended to include catheter infections without bloodstream infection in the presence of systemic illness without another source.

The clinical and economic consequences of nosocomial central venous catheter-related infection: are antimicrobial catheters useful?

Central venous catheters (CVCs) are essential for many hospitalized patients, but they are associated with important infectious complications. Recent studies have indicated that CVCs coated with antimicrobial agents reduce the incidence of catheter-related bloodstream infection (CR BSI). To estimate the clinical and economic consequences of short-term central venous catheter-related infection and the potential usefulness of antimicrobial-coated catheters, we reviewed and synthesized the available relevant literature. Statistical pooling was used to estimate the incidence of both catheter colonization and CR BSI. The attributable mortality of CR BSI was also evaluated. In addition, the economic consequences of both local and systemic catheter-related infection was estimated from literature reports that used micro-costing and other techniques. Among patients in whom standard, noncoated CVCs are in place for an average of 8 days, 24.7% are expected to develop catheter colonization (95% confidence interval [CI(95)], 22.0%-27.5%). Approximately 5.2% (CI(95), 3.9%-6.5%) will develop CR BSI. The attributable mortality of CR BSI remains unclear, but recent studies are consistent with a range from 4% to 20%. An episode of local catheter-related infection leads to an additional cost of approximately $400, whereas the additional cost of CR BSI ranges from approximately $6,005 to $9,738. Formal economic analyses indicate that CVCs coated with antibacterial agents (such as chlorhexidine-silver sulfadiazine or minocycline-rifampin) likely reduce infectious complications, yielding economic advantages. In light of the substantial clinical and economic burden of catheter-related infection, hospital personnel should adopt proven cost-effective methods to reduce this common and important nosocomial complication.

Diagnostic tests: distinguishing good tests from bad and even ugly ones

This article focuses on the selection and interpretation of diagnostic tests, emphasizing the importance of understanding how their mathematical parameters affect the information they provide in various settings. The utility and limitations of sensitivity, specificity, predictive value, and receiver operating characteristic (ROC) curves are discussed using catheter-related bloodstream infections as an example. ROC curves have been used for selecting optimal cutoff values for a positive result and for selecting among several alternative diagnostic tests. For example, 16 different tests have been proposed for diagnosis of catheter-related bloodstream infection; ROC analysis provides an effective way to determine which test offers the best overall performance.

[Effect of topical and oral diclofenac on superficial thrombophlebitis caused by intravenous infusion]

BACKGROUND

Until present time, suggested treatments for superficial thrombophlebitis induced by intravenous infusion (TFSI), are of uncertain effectiveness and most of them or empirical and not fully researched. The aim of this report is to study the effectiveness and safety of the topical and oral administration of diclofenac in the treatment of TFSI.

PATIENTS AND METHODS

In this prospective study 120 patients both female and male were included. All of them developed TFSI during hospitalization and at the same time they were assigned at random to one of the following groups: G-control (n = 40), without treatment; G-topical (n = 40), diclofenac emulsion gel used in a topical way on the concerned area every 8 hours during 48 hours; G-oral (n = 40), diclofenac 75 mg p.o. every 12 hours during 48 hours. The measurements were done at the moment of diagnosis of TFSI (T0) and 48 hours later (T2). Registries of intensity of TFSI were done by quantifying flushing, tumor, heatness and pain. These data were compared considering the averages of differences registered in T2 with respect to T0. A decrease of intensity of TFSI > or = 30% was considered a positive answer to this treatment. The quantitative variables were studied with ANOVA, Kruskal-Wallis test or general linear model and the qualitative with the chi 2 test with Yates correction. The level of significance used was alpha = 0.05.

RESULTS

The averages of differences in the intensity of TFSI that were registered in the groups G-control, G-topical and G-oral in T2 compared to T0 are: -0.12 (4.89), -5.70 (3.13), -4.82 (3.14) (p = 0.000). The favorable answers in G-control, G-topical and G-oral were: 20, 60 and 60%, respectively (p = 0.0001). The adverse reactions in G-topical and G-oral were: headache 9-5 (p = 0.2), epigastric pain 4-17 (p = 0.0009), nausea 6-16 (p = 0.01) and local pruritus 5-2 (p = 0.2). The treatment did not report serious adverse reactions in either of the groups.

CONCLUSION

The topical treatment of diclofenac can be recommended as an alternative simple, effective and safe therapy for patients who develop TFSI.

Efficacy of silver-coating central venous catheters in reducing bacterial colonization

OBJECTIVE

To compare silver-coated and uncoated central venous catheters regarding bacterial colonization. To assess the relative contribution of catheter hub and skin colonization to catheter tip colonization.

DESIGN

Prospective, randomized clinical trial.

SETTING

Intensive care unit in a university hospital.

PATIENTS

Patients after cardiac surgery who required a central venous double-lumen catheter (DLC).

INTERVENTIONS

Sixty-seven adult patients were prospectively randomized to receive either a silver-coated (S group, n = 34) or an uncoated control (C group, n = 33) DLC. Blood cultures were drawn at catheter removal, and removed catheters were analyzed with quantitative cultures. Typing of microorganisms included DNA fingerprinting.

MEASUREMENTS AND MAIN RESULTS

Catheters were removed if no longer necessary and aseptically divided into three segments: segment A, the catheter tip; segment B, an intermediate section; and segment C, the subcutaneous portion. Bacterial catheter colonization was quantitatively measured using sonication to detach adherent bacteria from the catheter segments in the broth and subsequent culture of an aliquot. Selected isolates of coagulase-negative staphylococci and other bacteria from catheter segments were examined by means of pulsed-field gel electrophoresis (PFGE) after macrorestriction digestion of bacterial DNA to study colonization pathogenesis. Quantitatively lower bacterial colonization could be demonstrated on the silver-coated catheters (200 +/- 550 colony forming units [CFUs]/cm catheter segment; mean +/- SD). The difference in the control catheters (1120 +/- 5350 CFUs/cm catheter segment; mean +/- SD) was not, however, significant (p = .25). The frequency of colonization of at least one catheter segment was 52.9% for the silver-coated catheters and 57.6% for the control catheters (p= .44), without any significant differences in the colonization of corresponding catheter segments. The rate of significant catheter colonization (i.e., > or = 10(3) CFUs/cm catheter by quantitative catheter culture or > or = 10(3) CFUs/mL by luminal flush) was nine in the silver group and seven in the control group, a difference that failed to reach significance (p = .41). Two patients in both groups developed catheter-related bacteremia. Pattern analysis after PFGE demonstrated that about 70% of the isolates found on the catheter tip were identical with those on the skin at the insertion site, whereas about 75% were identical with those recovered from the hub. In 29% of colonized catheters, identical bacteria were found on the hub and the skin at the insertion site.

CONCLUSIONS

Silver-coating of DLCs did not significantly reduce bacterial catheter colonization compared with the control catheters. PFGE analysis of coagulase-negative staphylococci and other bacteria demonstrated various pathogenic routes of catheter-related colonization, whereby the microorganisms of the skin flora around the insertion site must be regarded as the main source of catheter-related infections.

Infusion therapy team and dressing changes of central venous catheters

OBJECTIVE

To determine whether central venous catheter (CVC) dressing changes could be performed by ward nurses rather than by the infusion therapy team (ITT) nurses without increasing the risk of catheter-related infection.

DESIGN

Retrospective cohort study using prospectively collected data. The study extended from January 1995 to June 1996.

SETTING

The University of Texas M.D. Anderson Cancer Center, a referral cancer center.

PATIENTS

The study group was a random sample of 483 patients who received CVC dressing changes by ward nurses during the study period. A random sample of 483 patients who received CVC dressing changes by the ITT constituted the control group.

RESULTS

The risks of catheter-related septicemia were 1.7% among cases and 1.4% among controls (risk ratio, 1.14; 95% confidence interval [CI95], 0.26-6.42; P=.70). There also were no significant differences between the two groups in the risks of catheter-related site infection (risk ratio, 0.50; CI95, 0.02-4.12; P=.25) or any catheter-related infection (risk ratio=1.00; CI95, 0.27-3.64; P=.59).

CONCLUSIONS

Provided that aseptic techniques (including maximal barrier precautions during insertion) are maintained, the responsibility of CVC dressing changes could be delegated to the ward nurses without increasing the low risk of CVC-related infection, resulting in an estimated cost saving in excess of $90,000 per year.

In vitro antimicrobial activity of a new antiseptic central venous catheter

A central venous catheter coated with a new antiseptic combination, silver chloride (AgCl) and benzalkonium chloride (BKC) in a polymer matrix, was developed. The antimicrobial efficacy and the ability to prevent surface colonization, after elution in both serum and saline, were evaluated and compared to catheters coated with silver sulfadiazine/chlorhexidine. The results of in vitro assays demonstrated that the AgCl-BKC coated catheters had a broad spectrum of activity against bacteria and C. albicans and prolonged antimicrobial activity for extraction periods of up to 30 days. These data suggest that AgCl-BKC coated catheters may provide another solution for reduction of catheter-related infections.

Risk reduction in the intensive care unit

Many potentially preventable complications occur in patients who receive intensive care. We have reviewed the epidemiology of three important complications (venous thromboembolism, stress-related upper gastrointestinal bleeding, and vascular catheter-related infection) and evaluated common preventive treatments to provide evidence-based recommendations for prevention. We used English language articles located by MEDLINE or cross-citation, giving preference to articles published in the last 10 years, meta-analyses, and clinical trials that were randomized, double-blinded, and used intention-to-treat analysis. We recommend prophylaxis against venous thromboembolism in most patients, whereas those without respiratory failure or coagulopathy may not require prophylaxis against stress-related upper gastrointestinal hemorrhage. Chlorhexidine gluconate is the preferred antiseptic for disinfecting the skin prior to and during intravascular catheterization. Central venous catheters impregnated with antibacterial or antiseptic agents should be considered in patients at high risk for vascular catheter-related infection. Finally, central venous, pulmonary arterial, and systemic arterial catheters should be changed only when clinically indicated.

Infection control and outpatient parenteral antibiotic therapy

Outpatient procedures have become more complex, requiring outpatient providers to offer technical procedures in the home, office, and clinic. This shift in health care has brought about the need for staff members to become proficient in a variety of technical procedures that were once done only in the hospital setting. Outpatient i.v. therapy has caused home health care agencies, physicians' offices, and clinics to seek education and training regarding i.v. therapy and to develop basic infection-control guidelines and guidelines related to the insertion and maintenance of i.v. devices. The goals of the outpatient provider are to prevent i.v.-related complications and to provide quality patient care. These can be accomplished by strict adherence to sound infection-control guidelines and routine monitoring of procedure techniques and complications of care. Outpatient providers may wish to seek expertise and guidance from hospital infection-control personnel, infectious diseases specialists, or other infection-control consultants to meet the demands of the complexity of outpatient care.

I.v.-related phlebitis, complications and length of hospital stay: 1

This article, the first of two-parts, addresses the growing problem of intravenous-related phlebitis in hospitalized patients, and the resultant personal and financial costs to both patient and hospital. Literature on the various types of phlebitis, the factors that increase the patient's risk of developing phlebitis, clinical indicators and severity grading scales, and the complications of phlebitis are examined. Awareness of such factors is considered instrumental in minimizing the incidence of intravenous-related phlebitis. The second article in this series will present a study of 90 patients from a large teaching hospital, which was conducted to determine the incidence and severity of intravenous-related phlebitis, risk factors, associated complications, and the related length of hospital stay. The implications of the results for current and future nursing care of patients receiving i.v. therapy will be discussed, and recommendations for safe practice will be made.

Chylothorax and chylopericardium: a complication of a central venous catheter

This article describes a rare and severe complication of central venous catheterization, namely extensive thrombosis within the venous system of the chest resulting in bilateral chylothorax and chylopericardium. The complication resolved with drainage, catheter removal, and low molecular weight heparin therapy.

Candidaemia in an Australian teaching hospital: relationship to central line and TPN use

We performed a retrospective review of patient case records to identify risk factors for candidaemia and to assess incidence, management and outcome of candidaemia in an Australian teaching hospital. Between January 1994 and June 1996, 38 cases of candidaemia were identified. The incidence was 0.74 per 1000 admissions of 24 h duration, and 1.54 per 1000 admissions of 5 days or more. The mortality rate was 34%, with eight of 13 (62%) of these deaths attributable to candidaemia. Risk factors included underlying gastrointestinal disease (66%) and recent abdominal surgery (61%), while recent broad spectrum antibiotic use was a contributing factor in 95%. Twenty-nine patients (76%) had a vascular access device in situ at time of detection. This was the apparent source of candidaemia in 28 (97%). Twenty-six (90%) were being used for TPN administration. Of patients receiving TPN, 5.2% developed candidaemia. Standard central venous catheters (CVC) were present in 21 patients (55%), having been in situ for an average of 12.7 days. Eighteen (86%) had been in situ for 7 days or more. Management involved removal of any implicated intravascular device. Thirty of 33 early survivors received antifungal chemotherapy. Therapy with amphotericin B, fluconazole alone or amphotericin B followed by fluconazole was equally effective. Concurrent corticosteroid use and neutropaenia contributed to increased mortality. Candidaemia is not benign. Policies regarding regular changing of central lines, especially in the setting of TPN administration and control of broad spectrum antibiotic use are appropriate measures aimed to reduce incidence. Management involves removal of implicated lines and antifungal chemotherapy. Pre-emptive therapy for candida infection should be considered in selected patients with the likelihood of TPN-related central line sepsis. Fluconazole is an effective alternative to amphotericin B in non-neutropenic patients.

Diagnosis of vascular catheter-related bloodstream infection: a meta-analysis

Catheter-related bloodstream infections increased in incidence during the past decade, causing significant morbidity, mortality, and excess hospital costs. Absence of inflammation at the catheter site in most cases makes clinical diagnosis uncertain. The relative accuracy and cost-effectiveness of different microbiologic tests for confirming that bloodstream infection is catheter related have remained unclear. A meta-analysis of published studies was conducted regarding the accuracy of diagnostic test methods using pooled sensitivity and specificity and summary receiver operating characteristic (ROC) curve analysis. The cost for each test was estimated by methods published by the College of American Pathologists. Costs of catheter replacement and antibiotic therapy for false positive results were included in the cost per accurate test result. Twenty-two studies evaluating six test methods met inclusion criteria for the meta-analysis. Accuracy increased in ROC analysis for catheter segment cultures with increasing quantitation (P = 0.03) (i.e., quantitative > semiquantitative > qualitative) largely due to an increase in specificity. The highest Youden index (mean = 0.85) was observed with quantitative catheter segment culture, the only method with pooled sensitivity and specificity above 90%. For blood culture methods, there was no statistically significant trend toward increased accuracy. The unpaired quantitative catheter blood culture offered the lowest cost per accurate test result but was only 78% sensitive. In conclusion, quantitative culture was the most accurate method for catheter segment culture, and unpaired quantitative catheter blood culture was the single most cost-effective test, especially for long-term catheters.

Intravascular site care: are critical care nurses practicing according to written protocols?

OBJECTIVE

To observe and describe site care for intravascular devices, to identify internurse variations in site care, and to compare written protocols for site care with actual practice in one geographic area.

DESIGN

Observational, descriptive study.

SETTING

Adult critical care units in one community, and one university teaching hospital in the Washington, D.C., metropolitan area.

SAMPLE

Direct observation of 86 central and 30 peripheral site care episodes.

RESULTS

A total of 116 site care episodes were observed on five critical care units. There were wide variations between units from the same hospital in gloving practices and use of aseptic technique. Significant differences across both hospitals, as well as between individual units, were noted for a number of other practices including: time since last site care, use of ointment and skin adhesive, type of dressing used, and duration of care. In both hospitals, compliance with all steps of the written protocol was similar-23.2% and 23.3%. Compliance with documentation requirements ranged from 53.3% to 85.7%, and was significantly different between the two hospitals with regard to recording the dressing change and whether the dressing label and chart agreed.

CONCLUSIONS

Intravascular site care varies significantly among critical care units within the same institution, as well as between different hospitals, and varies from written protocol. Standardized, well-defined site care protocols and education of staff, along with quality improvement surveillance systems are needed to ensure consistent quality intravascular site care.

Infectious rates of central venous pressure catheters: comparison between newly placed catheters and those that have been changed

OBJECTIVE

To analyze the rate of infection of de novo, guidewire exchanged, and new site replacement catheters in a cohort of patients in whom catheters were changed on the basis of the clinical discretion of the attending physicians.

DESIGN

We conducted an observational cohort study in catheterized patients in the intensive-care unit (ICU).

MATERIAL AND METHODS

ICU patients admitted between Jan. 1, 1991, and Dec.31, 1992, were eligible for enrollment in the study. Catheter care, replacement, and duration were prospectively documented. Catheter-related infection was prospectively evaluated. Rates of catheter-related infection were determined for de novo, guidewire exchanged, and new site replacement catheters and analyzed relative to the duration of placement of individual catheters and the total duration of central venous catheterization for a specific patient.

RESULTS

Fifty catheter-related infections developed in 2,470 patients. When the rate of catheter-associated infection was determined for each type of catheterization, de novo catheters had a lower observed rate of infection than either replacement type (P < or = 0.0001). After controlling for the effect of time, we found that the rate of catheter-related infections associated with a de novo catheter was less than the rate in guidewire exchanged catheters (P = 0.035). Rates of infection were similar between guidewire exchanged catheters and catheters replaced to a new site.

CONCLUSION

In a population of ICU patients in whom catheter change was governed by clinical judgement, no differences were noted between the observed rates of infection of new site replacement catheters and guidewire exchange catheters.

In vitro antimicrobial efficacy of silver iontophoretic catheter

A silver iontophoretic catheter was designed consisting of two silver wires connected to an electric power source and disposed in a parallel and helical manner around the proximal subcutaneous segment of a silicone catheter. In an in vitro tunnelled bridge model the silver iontophoretic catheter prevented the migration of Staphylococcus epidermidis from the highly contaminated hub to the sterile tip over a 40-d period. The silver impregnated cuff and electrically charged wires made of aluminium or iron delayed migration for only 72 h. A modified Kirby-Bauer technique, used to test the inhibitory activity of antimicrobial catheters, showed that the silver iontophoretic catheter has a broad spectrum inhibitory activity against Gram-positive bacteria, Gram-negative bacteria and Candida albicans. The silver iontophoretic catheter provides a long-term electrochemical barrier against the migration of organisms from the external contaminated environment into the sterile intravascular compartment.

Central venous catheter-related infections: a review

Catheter-associated bloodstream infections remain an important cause of nosocomial infection, with an estimated 50,000-100,000 cases occurring each year in the United States. Central venous catheters are believed to be responsible for 90% of such infections. The cumulative risk of acquiring a catheter-related bloodstream infection has ranged between 1 and 10% for central venous catheters in general and 6% for total parenteral nutrition catheters. The skin is the most common source of organisms causing catheter-related infections. Recent prospective studies have shown that the incidence density per catheter day does not increase with duration of catheterization and that routine changes, either over a guidewire or by new site puncture, do not appear to lower the risk of infection. Diagnosis of infection can be difficult in intensive care patients but is usually easier in less ill patients with a central venous catheter. Quantitative or semiquantitative laboratory techniques can be used to confirm the diagnosis in the appropriate clinical setting. A variety of preventive measures have been shown to minimize the risk of development of catheter-related bloodstream infection, including use of maximal aseptic technique for insertion, use of special teams for care of the catheter, limiting manipulation of the catheter, use of povidone-iodine ointment and cotton gauze dressings for recently inserted catheters, a silver-impregnated collagen cuff and antiseptic-impregnated catheters.

Endovascular stent infection

We report a case of iliac stent infection. Nine days after a 24-hour infusion of urokinase and right iliac artery stent deployment, the patient had fever, in addition to severe groin pain and petechiae isolated to the stented limb. The hospital course was complicated by sepsis, adult respiratory distress syndrome, liver dysfunction, and renal insufficiency. Stent removal and iliac/femoral artery resection, as well as an above-knee amputation, were life-saving. Arterial and stent cultures grew Staphylococcus aureus. Stent infection with arterial necrosis is a devastating, rare endovascular complication. Given its potential seriousness, we would recommend the use of prophylactic antibiotics before stent deployment.

Antibiotics and prevention of microbial colonization of catheters

Slime-producing staphylococci frequently colonize catheters, and when they are embedded in biofilm, they become resistant to various antibiotics. In the study that is described, the comparative efficacies of vancomycin, clindamycin, novobiocin, and minocycline, alone or in combination with rifampin, were tested in an in vitro model of colonization. The model consisted of the modified Robbins device with antibiotic-impregnated cement filling the lumen of catheter segments. The synergistic combination of minocycline and rifampin was the most efficacious in preventing bacterial colonization of slime-producing strains of Staphylococcus epidermidis and Staphylococcus aureus to catheter surfaces. A similar trend was observed when the inhibitory activities of polyurethane catheters coated with minocycline and rifampin were compared with the inhibitory activities of catheters coated with other antimicrobial agents. The inhibitory activities of catheters coated with minocycline and rifampin against S. epidermidis, S. aureus, and Enterococcus faecalis strains, for example, were significantly better than those of catheters coated with vancomycin (P < 0.05). The inhibitory activities of catheters coated with minocycline and rifampin against gram-negative bacilli and Candida albicans were comparable to those of catheters coated with ceftazidime and amphotericin B, respectively. We found that the combination of minocycline and rifampin is unique and highly effective in preventing the colonization of catheters with slime-producing staphylococci and that it also displays a broad-spectrum inhibitory activity against gram-negative bacteria and yeast cells.

Patient factors and central line infection

The purpose of this prospective study was to examine the relationship between patient-related factors and the development of central venous catheter infection. Fifty-three patients, representing 64 central lines, were followed from catheter insertion to removal. Information about the patient's age, sex, immunocompetence status, central line characteristics, medication regimen, and laboratory results was obtained. Results showed that, of these factors, only the medication regimen was a promising predictor of infection status. Patients who were receiving antibiotics during central line catheterization were at less risk of developing infection than patients who were not receiving them.

Biofilms in device-related infections

The use of various medical devices including indwelling vascular catheters, cardiac pacemakers, prosthetic heart valves, chronic ambulatory peritoneal dialysis catheters and prosthetic joints has greatly facilitated the management of serious medical and surgical illness. However, the successful development of synthetic materials and introduction of these artificial devices into various body systems has been accompanied by the ability of microorganism to adhere to these devices in the environment of biofilms that protect them from the activity of antimicrobial agents and from host defense mechanisms. A number of host, biomaterial and microbial factors are unique to the initiation, persistence and treatment failures of device-related infections. Intravascular catheters are the most common devices used in clinical practice and interactions associated with these devices are the leading cause of nosocomial bacteremias. The infections associated with these devices include insertion site infection, septic thrombophlebitis, septicemia, endocarditis and metastatic abscesses. Other important device-related infections include infections of vascular prostheses, intracardiac prostheses, total artificial hearts, indwelling urinary catheters, orthopedic prostheses, endotracheal tubes and extended wear lenses. The diagnosis and management of biofilm-associated infections remain difficult but critical issues. Appropriate antimicrobial therapy is often not effective in eradicating these infections and the removal of the device becomes necessary. Several improved diagnostic and therapeutic modalities have been reported in recent experimental studies. The clinical usefulness of these strategies remains to be determined.