Severe anaphylactic reaction due to a chlorhexidine-impregnated central venous catheter

Review of allergic reactions from use of chlorhexidine on medical products in clinical settings over 40 years: Risks and mitigations

Chlorhexidine is an antimicrobial agent widely used for infection prevention in medical settings. Nevertheless, allergic reactions ranging from mild to severe have been reported following its use. In this review, we analyzed all case reports published between the introduction of chlorhexidine and the end of 2019 for allergic responses associated with the use of medical devices and or other medical products containing chlorhexidine (CHX) to ascertain the prevalence of severe CHX allergic reactions and what practices might best mitigate those risks.In total, 77 publications containing 124 reported cases of allergic reactions were grouped into 3 product categories, catheters, semisolids, and fluid products. The country, type of reaction, route of sensitization, allergy confirmation, and intervention or mitigation was extracted for each case. Overall, 30 cases were associated with catheters, 46 cases were associated with semisolid products, and 48 cases were associated with the use of other medical products. Severe cases were managed with intravenous fluids, steroids, and epinephrine (adrenaline). None of the reported cases were fatal. The allergy risks can be mitigated by better warning and training clinicians and by recording and screening patient histories for CHX presensitization from prior exposure. For patients undergoing pre-use blood tests, IgE antibody screens can also be performed. Finally, as a precaution in the event a rare severe allergic reaction occurs, procedure carts and rooms can be prestocked with injectable epinephrine and other rapidly acting anti-inflammatory medications.

Practice Guidelines for Central Venous Access 2020

These practice guidelines update the Practice Guidelines for Central Venous Access: A Report by the American Society of Anesthesiologists Task Force on Central Venous Access, adopted by the American Society of Anesthesiologists in 2011 and published in 2012. These updated guidelines are intended for use by anesthesiologists and individuals under the supervision of an anesthesiologist and may also serve as a resource for other physicians, nurses, or healthcare providers who manage patients with central venous catheters.

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Comparative epidemiology of suspected perioperative hypersensitivity reactions

Suspected perioperative hypersensitivity reactions are rare but contribute significantly to the morbidity and mortality of surgical procedures. Recent publications have highlighted the differences between countries concerning the respective risk of different drugs, and changes in patterns of causal agents and the emergence of new allergens. This review summarises recent information on the epidemiology of perioperative hypersensitivity reactions, with specific consideration of differences between geographic areas for the most frequently involved offending agents.

Antimicrobially Impregnated Catheters: An Overview of Randomized Controlled Trials

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 randomized controlled trials (RCTs). The analysis end point was CRI; therefore, studies focussing only on catheter colonization were excluded. We did not consider abstracts 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.

Anti-Candida activity of antimicrobial impregnated central venous catheters

Background

Whenever the rate of central line-associated bloodstream infections (CLABSIs) remains high even after the implementation of preventive strategies, the use of chlorhexidine/silver sulfadiazine (CSS) or minocycline/rifampin (MR)-impregnated central venous catheters (CVCs) is currently recommended. Nevertheless, the efficacy of such CVCs against Candida albicans and other emerging non-albicans spp. has been insufficiently studied. This study aims to compare the activity of CSS and MR-impregnated CVCs against the yeasts most frequently isolated from CLABSIs.

Methods

For biofilm formation assays, type strains and clinical isolates of C. albicans, C. glabrata and C. parapsilosis sensu stricto were used. Segments of standard polyurethane, MR and second-generation CSS-CVCs were tested. The biofilm metabolic activity was measured by a semi-quantitative XTT reduction assay.

Results

CSS catheter segments significantly reduced the biofilm metabolic activity by all tested Candida spp., with inhibition ranging from 60% to 100%. The MR catheter segments promoted C. albicans and C. parapsilosis biofilm formation and exhibited an inconspicuous effect against C. glabrata.

Conclusions

Among the recommended antimicrobial CVCs, CSS-CVCs proved to be superior in the inhibition of biofilm formation by the most frequent yeasts causing CLABSIs. Data from this in vitro study may suggest that patients at high risk for invasive candidosis could benefit from the use of CSS-CVCs.

Chlorhexidine-silver sulfadiazine-impregnated venous catheters are efficient even at subclavian sites without tracheostomy

BACKGROUND

Chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters have been found to decrease the risk of catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, there are no published data about cost-effectiveness of the use of CHSS-impregnated catheters in subclavian venous access without the presence of tracheostomy (thus, with a very low risk of CRBSI). That was the objective of this study.

METHODS

This was a retrospective study of patients admitted to a mixed intensive care unit who underwent placement of subclavian venous catheters without the presence of tracheostomy.

RESULTS

Patients with standard catheters (n = 747) showed a higher CRBSI incidence density (0.95 vs 0/1,000 catheter-days; P = .02) and higher CVC-related cost per day ($3.78 ± $7.43 vs $3.31 ± $2.72; P < .001) than patients with a CHSS-impregnated catheter (n = 879). Exact logistic regression analysis showed that catheter duration (P = .02) and the type of catheter used (P = .01) were associated with the risk of CRBSI. Kaplan-Meier method showed that CHSS-impregnated catheters were associated with more prolonged CRBSI-free time than standard catheters (log-rank = 9.76; P = .002). Poisson regression analysis showed that CHSS-impregnated catheters were associated with a lower central venous catheter-related cost per day than standard catheters (odds ratio, 0.87; 95% confidence interval, 0.001-0.903; P < .001).

CONCLUSIONS

The use of CHSS-impregnated catheters is an effective and efficient measure for the prevention of CRBSI even at subclavian venous access sites without the presence of tracheostomy.

Chlorhexidine-silver sulfadiazine- or rifampicin-miconazole-impregnated venous catheters decrease the risk of catheter-related bloodstream infection similarly

BACKGROUND

The objective of this study was to compare the incidence of catheter-related bloodstream infection (CRBSI) with the use of second-generation chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters, rifampicin-miconazole (RM)-impregnated catheters, and standard catheters.

METHODS

Retrospective study of patients admitted to an intensive care unit who received CHSS, RM, or standard catheters in femoral venous access.

RESULTS

We diagnosed 18 CRBSIs in 245 patients with standard catheters in 2,061 days, zero CRBSI in 169 patients with CHSS-impregnated catheters in 1,489 days, and zero CRBSI in 227 patients with RM-impregnated catheters in 2,009 days. Patients with standard catheters compared with CHSS- and RM-impregnated catheters showed a higher rate of CRBSI (7.3%, 0%, and 0%, respectively; P < .001) and higher incidence density of CRBSI (8.7, 0, and 0 per 1,000 catheter days, respectively; P < .001). We found in the exact Poisson regression that standard catheters were associated with a higher CRBSI incidence than CHSS-impregnated catheters (P < .001) and RM-impregnated catheters (P < .001), controlling for catheter duration. We found in survival analysis that standard catheters were associated with a lower CRBSI-free time than CHSS-impregnated catheters (P < .001) and RM-impregnated catheters (P < .001).

CONCLUSION

We found that CHSS- and RM-impregnated catheters decreased similarly the risk of CRBSI.

Chlorhexidine-induced anaphylaxis in surgical patients: a review of the literature

BACKGROUND

Chlorhexidine (CHL) has antiseptic and disinfectant properties used to prevent hospital-acquired infections. CHL-induced anaphylaxis is poorly reported in surgical literature despite government warnings and growing recognition. The aim of this review is to increase awareness of CHL-induced anaphylaxis in the surgical population.

METHODS

Literature review of Embase, Medline, PubMed and the Cochrane library using 'anaphylaxis (and) chlorhexidine' search terms.

RESULTS

Thirty-six articles were published on surgical patients suffering anaphylaxis to CHL. Within these, seven patients had two proven separate anaphylactic reactions and one had three separate proven anaphylactic reactions. The most commonly affected speciality was urology. The majority occurred during elective procedures. A history of atopy was surprisingly uncommon as was bronchospasm. Six patients required active chest compressions and 39.71% of patients had their surgical procedure abandoned. Unplanned intensive care admissions occurred in 27.94%.

DISCUSSION

In order to reduce abandoned procedures, unplanned intensive care unit admissions, morbidity and mortality associated with CHL-induced anaphylaxis we recommend the following: rationalization of CHL-containing products, greater vigilance regarding subtle symptoms of CHL allergy, appropriate investigation of these symptoms and a greater awareness of CHL-containing products. Lastly, we outline the appropriate investigations and highlight the need for meticulous documentation in those who are CHL allergic.

Efficiency of chlorhexidine-silver sulfadiazine-impregnated venous catheters at subclavian sites

BACKGROUND

Cost-effectiveness analyses show that chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters reduce catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, no studies have reported the efficiency of CHSS-impregnated catheters for venous access when the risk of CRBSI is low; for example, at the subclavian site. This study determined the cost of a CVC, diagnosis of CRBSI, and antimicrobial agents to treat CRBSI; we did not consider the cost of increased hospital stay.

METHODS

This retrospective study included patients admitted to the intensive care unit at Hospital Universitario de Canarias (Tenerife, Spain) who had a subclavian venous catheter.

RESULTS

Patients with CHSS catheters (n = 353) had a lower incidence density of CRBSI (2.12 vs 0 out of 1,000 catheter-days; P = .02) and lower CVC-related cost per catheter-day (3.35 ± 3.75 vs 3.94 ± 9.95; P = .002) than those with standard catheters (n = 518). CHSS-impregnated catheters were associated with a lower risk of CRBSI (exact logistic regression) (odds ratio, 0.10; 95% confidence interval, -∞ to 0.667; P = .008) than standard catheters when controlling for catheter duration. CHSS-impregnated catheters were also associated with a lower CVC-related cost per catheter day than standard catheters (Poisson regression) (odds ratio, 0.85; 95% confidence interval, 0.001-0.873; P < .001).

CONCLUSIONS

CHSS-impregnated catheters may be efficient in preventing CRBSI in patients with subclavian venous access.

Chlorhexidine: an unrecognised cause of anaphylaxis

Chlorhexidine is a highly effective antiseptic and disinfectant. In the past 20 years there has been a substantial increase in the number of chlorhexidine containing products used in healthcare. Anaphylaxis to chlorhexidine was first reported in 1984 and was almost always seen in men. However, in the last 4 years we have observed a surge in confirmed cases of anaphylaxis to chlorhexidine, with increasing numbers of female patients recently diagnosed. Yet, awareness of chlorhexidine as a cause of anaphylaxis is low because it is not a drug but a 'hidden' allergen, for example as a coating on medical devices such as central lines and urinary catheters. Patients will often have more than one allergic/anaphylactic reaction before the diagnosis is suspected. We have observed that there is poor recognition of an initial allergic reaction to chlorhexidine, which is well described. This, alongside poor labelling of chlorhexidine containing products, has resulted in further inadvertent exposure resulting in severe anaphylaxis. Prompt referral to a specialist allergy centre ensures appropriate investigations, diagnosis and management. Increasing awareness of the potential risk of life-threatening anaphylaxis associated with chlorhexidine use is vital, particularly in perioperative procedures. Healthcare workers are fundamental in avoiding and preventing further reactions to chlorhexidine containing products in patients diagnosed with anaphylaxis to chlorhexidine.

Cost/benefit analysis of chlorhexidine-silver sulfadiazine-impregnated venous catheters for femoral access

Sixty-four patients with chlorhexidine-silver sulfadiazine-impregnated catheters had a lower rate of catheter-related bloodstream infection and lower central venous catheter-related costs per catheter day than 190 patients with a standard catheter.

Chlorhexidine-silver sulfadiazine-impregnated venous catheters save costs

BACKGROUND

Previous cost-effectiveness analyses have found that the use of chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters is associated with decreased catheter-related bloodstream infections (CRBSI) and central venous catheter (CVC)-related costs. However, in these analyses, the CVC-related cost included the increase of hospital stay.

OBJECTIVE

Our aim was to determine the immediate CVC-related cost (including only the cost of CVC, diagnosis of CRBSI, and antimicrobials for the treatment of CRBSI) of using a CHSS or a standard catheter in internal jugular venous access.

METHODS

We performed a prospective, observational, cohort study of patients admitted to the intensive care unit (ICU), Hospital Universitario de Canarias (Tenerife, Spain), who received 1 or more internal jugular venous catheters.

RESULTS

The study included 245 CHSS-impregnated catheters and 391 standard catheters. Exact logistic regression analysis showed that CHSS-impregnated catheters were associated with a lower incidence of CRBSI, controlling for catheter duration, than standard catheters (0 vs 5.04 CRBSI per 1,000 catheter-days, respectively; odds ratio, 0.80; 95% confidence interval: 0.712-0.898; P < .001). Poisson regression showed that CHSS-impregnated catheters were associated with lower CVC-related cost per day than standard catheters (€3.78 ± €4.45 vs €7.28 ± €16.71, respectively; odds ratio, 0.52; 95% confidence interval: 0.504-0.535; P < .001). Survival analysis showed that CHSS-impregnated catheters were associated with increased CRBSI-free time compared with standard catheters (χ(2) = 14.9; P < .001).

CONCLUSION

The use of CHSS-impregnated catheters reduced the incidence of CRBSI and immediate CVC-related costs in the internal jugular venous access.

Preparation of carboxylated Ag nanoparticles as a coating material for medical devices and control of antibacterial activity

Carboxyl group-donated silver (Ag) nanoparticles for coating on medical devices were prepared by a two-phase reduction system in situ. AgNO3 was the Ag ion source, tetraoctylammonium bromide [N(C8H17)4Br] the phase-transfer agent, sodium tetrahydroborate (NaBH4) the reducing agent and 10-carboxy-1-decanthiol (C11H22O2S, CDT) the capping agent. The characterizations of the Ag nanoparticles were conducted by diffuse reflectance Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric differential thermal analysis (TG/DTA) and transmission electron microscope. With CDT capped on Ag nanoparticles, we found that the band around 3,100 cm(-1) was attributed to COO-H stretching vibration, two adsorptions at 2,928 and 2,856 cm(-1) to C-H symmetric/anti-symmetric stretching vibration, and at 1,718 cm(-1) to C=O stretching vibration in the FT-IR spectra. The organic components of the carboxylated Ag nanoparticles were 5.8-25.9 wt%, determined by TG/DTA. The particle sizes of the carboxylated Ag nanoparticles were well controlled by the addition of the capping agent, CDT, into the reaction system. The antimicrobial activity of the Ag nanoparticles covered with different contents of CDT against E. coli was evaluated. Smaller-size Ag nanoparticles showed higher antibacterial activity, which depended on a surface area that attached easily to a microorganism cell membrane.

Anaphylaxis to chlorhexidine-coated central venous catheters: a case series and review of the literature

BACKGROUND

Anaphylactic reactions to chlorhexidine are rare but are being reported increasingly in association with a variety of products.

METHODS

We report three cases of anaphylaxis to chlorhexidine in patients presenting for cardiac surgery.

RESULTS

In each case, anaphylaxis was precipitated by the insertion of a central venous catheter impregnated with chlorhexidine acetate. Subsequent investigations confirmed chlorhexidine as the causal agent.

CONCLUSION

Extensive use of chlorhexidine to reduce hospital-acquired infections has the potential to sensitize a small proportion of patients, leading to life-threatening anaphylaxis on subsequent exposure.

Chlorhexidine impregnated central venous catheter inducing an anaphylatic shock in the intensive care unit

Chlorhexidine, a bisbiguanide, is widely used as an antiseptic agent in medical practice as it has the greatest residual antimicrobial activity. Central venous catheters coated extraluminally with chlorhexidine have been made to reduce extraluminal contamination. By using both the chlorhexidine-alchohol skin preparation and antimicrobial-coated catheters during vascular cannulation, it can reduce catheter related bloodstream significantly [1]. The reduction in infection rate is especially vital in critically ill patients who require long-term vascular access. Adverse reactions to chlorhexidine are rare and uncommon, and have been under-recognised as a cause of anaphylaxis. There are several reports of allergic reactions following exposure to chlorhexidine. We report of a case of anaphylaxis shock requiring cardiopulmonary resuscitation during the placement of a chlorhexidine impregnated central venous catheters.

Nisin adsorption to hydrophobic surfaces coated with the PEO-PPO-PEO triblock surfactant Pluronic F108

The adsorption and elution of the antimicrobial peptide nisin at hydrophobic, silanized silica surfaces coated with the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactant Pluronic F108 were measured in situ, with ellipsometry. While such layers are known to inhibit protein adsorption, nisin was observed to adsorb in multilayer quantities, to an extent similar to its adsorption at uncoated, hydrophobic surfaces. The rates of nisin adsorption and elution were generally slower at F108-coated surfaces. And, the sequential adsorption of nisin, including two adsorption-elution cycles at each surface, showed greater differences in adsorption rates between the first and second adsorption cycles, when evaluated at identical mass density, for uncoated relative to F108-coated surfaces. These results indicate that nisin adsorption occurs via "entrapment" within the PEO brush layer at F108-coated surfaces, in this way slowing adsorption and spontaneous elution, and inhibiting post-adsorptive molecular rearrangements by reducing the lateral mobility of nisin. While F108-coated layers rejected adsorption of serum albumin, sequential adsorption experiments carried out with nisin and albumin showed a low level of albumin adsorption when nisin was present at the interface.

An update on antimicrobial central venous catheters

Antimicrobial central venous catheters make use of a variety of antimicrobial mechanisms. Although they are currently infrequently used and their role in preventing infection is still being defined, they have a clear application in certain situations.

Antimicrobial impregnated catheters in the prevention of catheter-related bloodstream infection in hospitalized patients

Catheter-related bloodstream infections have a significant impact on increasing health care costs and morbidity and mortality in hospitalized patients. Many technologies have been created in an attempt to decrease the incidence of catheter-related bloodstream infection. One of these is the impregnation of central venous catheters with antiseptics (e.g., chlorhexidine and silver sulfadiazine) or antibiotics (e.g., minocycline and rifampin). While studies evaluating the efficacy of impregnated catheters have been conducted, the data are limited and their use remains variable across institutions. This paper will discuss catheter-related factors that predispose patients to catheter-related bloodstream infection, the types of antimicrobial-impregnated catheters in use today, studies evaluating their efficacy, and common concerns associated with the use of these catheters. Issues related to the cost-effectiveness of impregnated catheters and future directions for the prevention of catheter-related bloodstream infection will also be presented.

Chlorhexidine anaphylaxis: case report and review of the literature

Chlorhexidine is a widely used antiseptic and disinfectant. Compared to its ubiquitous use in medical and non-medical environments, the sensitization rate seems to be low. Multivarious hypersensitivity reactions to the agent have been reported, including delayed hypersensitivity reactions such as contact dermatitis, fixed drug eruptions and photosensitivity reactions. An increasing number of immediate-type allergies such as contact urticaria, occupational asthma and anaphylactic shock have been reported. In the case report, we describe anaphylaxis due to topical skin application of chlorhexidine, confirmed by skin testing and sulfidoleukotriene stimulation test (CAST(R): cellular antigen stimulation test). The potential risk of anaphylactic reactions due to the application of chlorhexidine is well known, especially that application to mucous membranes can cause anaphylactic reactions and was therefore discouraged. The use of chlorhexidine at a 0.05% concentration on wounds and intact skin was so far thought to be safe. Besides our patient, only one other case of severe anaphylactic reaction due to application of chlorhexidine on skin has been reported. Hypersensitivity to chlorhexidine is rare, but its potential to cause anaphylactic shock is probably underestimated. This review should remind all clinicians of an important potential risk of this widely used antiseptic.

Is there a risk of sensitization and allergy to chlorhexidine in health care workers?

BACKGROUND

In Denmark, chlorhexidine is the standard disinfectant in most hospitals and health care workers are repeatedly exposed to it. The aim of this study was to establish whether there is a risk of sensitization and allergy to chlorhexidine from this type of exposure.

METHODS

Two hundred and forty-eight doctors, nurses and auxiliary staff were invited to participate in the study. One hundred and four individuals took part in the full study including skin tests and a questionnaire and a further 74 individuals filled in the questionnaire giving a total of 178 questionnaires (72%). Patch tests with chlorhexidine gluconate 1% and chlorhexidine acetate 1% were performed looking for type IV (delayed type) allergy. A prick test with chlorhexidine gluconate 0.5% and an intradermal test with chlorhexidine 0.0002% were performed looking for type I (immediate type) allergy.

RESULTS

There were no positive tests in any of the 104 individuals tested (99% confidence interval 0-4.9%). There was a predominance of females in both groups and the overall median age was 42 years (28-63). No one in the group not tested reported to have a verified or suspected allergy to chlorhexidine.

CONCLUSION

In this first study to examine the risk of type I and type IV allergy to chlorhexidine in health care workers with daily exposure to chlorhexidine, we did not identify allergies to chlorhexidine in any of the 104 individuals tested or in the additional 74 individuals who completed the questionnaire. We conclude that an allergy to chlorhexidine in health care workers is likely to be rare.

Effect of central venous catheter type on infections: a prospective clinical trial

This study reports on a block clinical trial of two types of central venous catheters (CVCS): antiseptic-impregnated catheters (AIC) and non-impregnated catheters (non-AIC), on catheter tip colonization and bacteraemia. In total, 500 catheters were inserted in 390 patients over the 18 month study period, 260 (52.0%) AIC and 240 (48.0%) non-AIC. Of these, 460 (92.0%) tips (237 AIC and 223 non-AIC) were collected. While significantly fewer AIC, 14 (5.9%), than non-AIC, 30 (13.5%), catheters were colonized (P<0.01), there was no difference in the rates of bacteraemias in the two groups (0.8% vs. 2.7%, respectively, P=0.16). There were 6.87 (95% CI 3.38-14.26) and 16.92 (95% CI 10.61-27.12) colonized AIC and non-AIC catheters, respectively, per 1000 catheter days, a difference that was significant (P<0.01). However, no difference emerged between bacteraemias in AIC and non-AIC catheters per 1000 catheter days measured at 0.98 (95% CI 0.24-5.54) and 3.38 (95% CI 1.29-9.34), respectively (P=0.10). Of the 444 CVCs that were sited in the subclavian or jugular veins and had tips collected, significantly more catheters were colonized in the jugular group, 19 (20%), compared with the subclavian group, 24 (6.9%; P< or =0.01). Overall, the low rates of colonization and bacteraemia may be explained by the population studied, the policies used and the employment of a clinical nurse dedicated to CVC management.

Prevention of bloodstream infections with central venous catheters treated with anti-infective agents depends on catheter type and insertion time: evidence from a meta-analysis

OBJECTIVE

To test the evidence that the risk of infection related to central venous catheters (CVCs) is decreased by anti-infective coating or cuffing.

DESIGN

Systematic review of randomized, controlled trials comparing anti-infective with inactive (control) CVCs.

INTERVENTIONS

Average insertion times were taken as a measurement of the length of insertion. Dichotomous data were combined using a fixed effect model and expressed as odds ratio (OR) with 95% confidence interval (CI95).

RESULTS

Two trials on antibiotic coating (343 CVCs) had an average insertion time of 6 days; the risk of BSI decreased from 5.1% with control to 0% with anti-infective catheters. There were no trials with longer average insertion times. In three trials on silver collagen cuffs (422 CVCs), the average insertion time ranged from 5 to 8.2 days (median, 7 days); the risk of BSI was 5.6% with control and 3.2% with anti-infective catheters. In another trial on silver collagen cuffs (101 CVCs), the average insertion time was 38 days; the risk of BSI was 3.7% with control and 4.3% with anti-infective catheters. In five trials on chlorhexidine-silver sulfadiazine coating (1,269 CVCs), the average insertion time ranged from 5.2 to 7.5 days (median, 6 days); the risk of BSI decreased from 4.1% with control to 1.9% with anti-infective catheters. In five additional trials on chlorhexidine-silver sulfadiazine coating (1,544 CVCs), the average insertion time ranged from 7.8 to 20 days (median, 12 days); the risk of BSI was 4.5% with control and 4.2% with anti-infective catheters.

CONCLUSIONS

Antibiotic and chlorhexidine-silver sulfadiazine coatings are anti-infective for short (approximately 1 week) insertion times. For longer insertion times, there are no data on antibiotic coating, and there is evidence of lack of effect for chlorhexidine-silver sulfadiazine coating. For silver-impregnated collagen cuffs, there is evidence of lack of effect for both short- and long-term insertion.

Can we achieve consensus on central venous catheter-related infections?

Central venous catheter-related bacteraemia is a substantial and preventable source of iatrogenic morbidity and mortality. A single episode of catheter-related bacteraemia has an estimated cost of A$50,000, with an attributable mortality between 10 and 35%. Catheter colonization is diagnosed with standard culture techniques. Diagnostic criteria for catheter-related bacteraemia include the results of cultures from the catheter tip, the peripheral blood and other possible sites of infection. The presence of clinical symptoms and subsequent defervescence may assist in making the diagnosis. This review explores the existing definitions of catheter-related infections and proposes a new and more rigorous classification with criteria for definite, probable and possible catheter-related bacteraemia. The authors hope that this classification will enhance the interpretation of the literature and the planning of new investigations. Infection rates can be reduced by appropriate site selection, adequate skin preparation, sterile technique and appropriate dressings. Decreased manipulation of administration sets, with more careful technique and less frequent set replacement, may reduce hub contamination. Infection rates increase with the duration in situ of the catheter, however are not reduced by regular scheduled catheter replacement or guide-wire exchanges. A range of antimicrobial catheter materials and coatings are under investigation, some of which are effective in reducing the rate of catheter-related bacteraemia. Chorhexidine-silver sulphadiazine and rifampicin-minocycline are the best studied combinations to date. Further developments are expected, although none are likely to be as effective as not inserting or removing the central venous catheter when it is not required.

Evaluation of antiseptic-impregnated central venous catheters for prevention of catheter-related infection in intensive care unit patients

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 randomized 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 standard triple-lumen polyurethane catheter or an antiseptic catheter (Arrow International, Reading, Pennsylvania, USA). Both were indistinguishable from each other. Compared to standard 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 standard 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 candidemia. 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 standard catheters in the critically ill patients.