Infection control related to central venous catheter impregnated with antiseptics : an integrative review

Infection control related to central venous catheter impregnated with antiseptics: an integrative review Ferreira MVF, Andrade D, Ferreira AM Rev Esc Enferm USP 2011; 45(4):993-7 www.ee.usp.br/reeusp/ Infection control related to central venous catheter impregnated with antiseptics: an integrative review* C r it iC a l r e v ie w CONTROLE DE INFECÇÃO RELACIONADA A CATETER VENOSO CENTRAL IMPREGNADO COM ANTISSÉPTICOS: REVISÃO INTEGRATIVA


ABSTRACT
The use of central venous catheter is pointed out as a risk factor to blood stream infection. The objective of this study was to reach scientific evidence on infection control related to central venous catheter impregnated with antiseptics, used in hospitalized adult patients. Studies were selected from the LILACS, CINAHL and MEDLINE databases. Nine articles were selected by means of integrative literature review. The publications on the use of catheters impregnated with antiseptics showed statistically significant differences regarding the reduction of microbial colonization; however, only one study showed reduction in the occurrence of infection. The analysis of the studies revealed there is a need for further research in different patient populations in order to obtain general conclusions.

INTRODUCTION
Infections associated to health care are a serious problem posing a global challenge, especially considering the variability of diagnoses and therapeutic procedures.
More specifically, vascular catheter (VC)-related infections are worrisome due to the severity and lethality involved (1)(2). VC etiology is complex and multifactorial. Studies have highlighted that aspects calling for greater attention include: the clinical conditions of the patients, catheter type, composition, insertion technique, location, the frequency of handling the system, and the duration.
The use of antiseptics has been investigated as one of the possibilities of changing properties of the surface of the device and reducing catheter microbe colonization. Acknowledging this possibility has, over the last decades, implemented the use of antiseptic-impregnated catheters (1)(2)(3) .
This study was performed using evidence based practice (EBP), as its approach allows for a systematic use of the best available evidence to evaluate options and make decisions when providing comprehensive patient care (4) .
In this sense, the main objective established for this study was to search evidence on the association between the use of antiseptic-impregnated central venous catheter (CVC) and the reduction of bloodstream infection (BSI).

METHOD
This is an integrative literature review that permits to summarize previous studies and establish conclusions based on a thorough analysis of the methodological outline and results regarding the investigated theme (5)(6) .
The following question was used to guide this study: The inclusion criteria were: articles available in full; use of central venous catheter without cuff, not tunneled, short permanence, antiseptic-impregnated in hospitalized adult patients; indexed in the abovementioned databases; published in English, Spanish, or Portuguese, between 1996 and 2006, with evidence levels I and II, according to Ganong (5) and with Stetler classification (6) .

RESULTS AND DISCUSSION
Nine articles on antiseptic-impregnated CVC were found, seven (77.8%) of which corresponded to randomized controlled trials (evidence level II), and two (22.2%) to meta-analyses (evidence level I). All articles were in English. Chart 1 shows a summary of the main aspects analyzed in the articles.
The researchers of the randomized clinical trials evaluated the effectiveness of using CVC impregnated on the external surface with chlorhexidine and silver sulfadiazine as to the reduction in catheter-related infections (7)(8)(9)(10)(11)(12) .
The studies demonstrated that most patients were under a high risk of catheter-related infection. As to the number of lumens, most corresponded to double-and triplelumen. In this context, a meta-analysis demonstrated that those with multiple lumens were most prone to infection compared to those with single lumen (13) .
As to the mean catheter permanence time, the period ranged between 7.8 to 8.4 days and 14.3 to 16.6 days. In this reference, some authors reported these catheters were effective only if used for approximately 10 days; and that, after this period, infection is mostly intraluminal. Furthermore, the bactericide effect of the devices was limited to the surface of catheters, not extending to the lumens (14)(15) .
Only one study made reference to using a guidewire to change catheters in the same insertion site. It should be highlighted that some researchers do not recommend changing the CVC periodically with the purpose of reducing infection, and accepted using the guidewire only in cases of bad functioning if there is there no evidence of infection (16)(17) .
Four studied recommended using the aseptic technique for CVC insertion, whereas two articles did not specify using individual protection equipment, but reported the rigor of asepsis when inserting the device. The preparation for CVC insertion (using overalls, gloves and sterile fields, caps and masks) is well documented in the study and supported by experts (18)(19)(20)(21)  As to the type of antiseptic solution used, it was observed there was a variability of products and their indication, i.e., iodine solutions at 10% with 1% free iodine, alcohol at 70% or 75%, and aqueous chlorhexidine at 2%. In this respect, researchers evaluated the use of chlorhexidine gluconate at 2% for CVC insertion compared to the iodine solution at 10%, and confirmed a reduction in CRBSI from 11.3 per 1000 CVC/day to 3.7 per 1000 CVC/day. There is vast literature addressing the evaluation of antimicrobial activity of antiseptics; and, has demonstrated the effectiveness of using chlorhexidine gluconate at 2% compared to iodine solutions at 10% or alcohol at 70% (20)(21)(22)(23) .
As to the CVC insertion site, it was observed that the most common site are the subclavian veins, and the least common are the jugular and femoral veins. Catheters inserted in the internal jugular veins have a higher risk for infection compared to insertions in the subclavian vein, considering its proximity to oropharyngeal secretions. In addition, it also implies greater difficulty to immobilize the catheter. Insertions in the femoral vein should be avoided, considering the high risk of complications such as deep venous thrombosis and infection, especially in incontinent adults (24)(25) . Jaeger, K. et al. (18) Ostendorf, T. et al. (19)

Authorship Study Objective Outline Results
To determine the effectiveness of antiseptic-impregnated and regular CVC on reducing insertion site infection and catheter-related sepsis.
To compare the bacteria colonization incidence of catheters impregnated with chlorhexidine and silver sulfadiazine and catheters without antiseptic coverage To evaluate the efficiency of CVC impregnated with chlorhexidine and silver sulfadiazine in preventing catheter colonization and catheterrelated bloodstream infection (CRBSI).
To compare the efficiency between CVC with and without antiseptics in preventing catheter-related infection (CRI) and colonization.
To establish the possible benefits silver-ion-impregnated CVC.
The analyze the methodological quality of individual controlled randomized clinical trials about catheters impregnated with chlorhexidine and silver sulfadiazine and their effects on CRI To establish the effectiveness of CVC impregnated with chlorhexidine and silver sulfadiazine.
To establish the efficiency of CVC impregnated with chlorhexidine and silver sulfadiazine To investigate catheters impregnated with chlorhexidine and silver sulfadiazine. The catheter-related sepsis rate was 02 (6%) in the experimental group, and 03 (8%) in the control group; and insertion-site infection was identified in 04 catheters (10%) of the experimental group, and in 04 (12%) of the control group. No statistically significant differences were found for catheter-related sepsis.

Randomized
The results from the catheter-tip cultures evinced positive results for 25 (71%) of the 35 patients from the control group, against only 10 (23%) of the 44 patients of the experimental group, p<0.002 versus p<0.05. The use of antiseptic-impregnated catheters reduced catheter tip colonization.
The summary odds ratio for colonization was 0.44 (P<.001), indicating a significant reduction in colonization associated to antiseptic-impregnated catheters. Studies that examined CRBSI showed a summary odds ratio of 0.56 (P=.005). The antisepticimpregnated CVC appear to be efficient in reducing the incidence of catheter colonization.
None of the patients showed hypersensitivity, local or systemic toxicity. The antisepticimpregnated catheter reduced infection incidence, but there were no statistically significant results. As to catheter colonization, 09 in the experimental group were colonized against 25 in the control group (p=0.006 to p<0.05). As to CRBSI, experimental group (01 catheter) and control group (2 catheters), p=0.53. Patients with antiseptic-impregnated catheters showed a smaller risk to bacteria colonization.
Contamination episodes occurred in 10 patients of the experimental group and 14 of the control. Six patients (12%) in the experimental group showed signs of infection, three of which were related to the catheter; against 10 patients of the control group (21%), with three relating to the catheter. There were no differences in the groups regarding catheter-related systemic infection rates. The study did not find statistically significant benefits for using silver-ion-impregnated catheters.
Summary odds ratio of the information from the 11 studies did not provide statistically significant results; however, there appears to be a tendency of benefits from impregnated catheters in the prevention of CRI. The quality of the studies did not affect the results; Information such as permanence time and use of antibiotics should be included in the studies, and methodological flaws should be avoided.
Colonization episodes occurred in 14 (5.9%) patients of the antiseptic-impregnated catheter group, and in 30 (13.5%) of the group using catheters without antiseptics (p<0.01 to p=0.05). However, regarding the bacteremia rate per 1000 catheters-day there were no differences between the groups (0.98 group with impregnated catheters and 3.38 for catheters without antiseptics). Catheter colonization was significantly smaller in the impregnated catheter group Colonization episodes occurred in 05 (9.8%) patients of the experimental group and 09 (16.4%) of the control group (p=0.035 to p=0.05). One patients of the experimental group has CRBSI against eight in the c control group (p=0.02). Antisepticimpregnated catheters reduce colonization.
The control group showed higher catheter colonization rates compared to the experimental group, i.e., 33 and 12%, respectively (p=0.1 to p=0.05). As to catheterrelated bacteremia, the rates found were 7% in the control group 7% and 3% in the experimental group (p=0.21). Antiseptic-impregnated catheters were effective in reducing bacterial growth and catheter colonization rates. Regarding the type of dressings, two studies point at the use of transparent coverings in CVC maintenance, and two dressings, sterile gaze and adhesive tape. It is important to stress that aspects related to dressings are complex and controversial. Furthermore, in cases that include drainage (blood or body fluids) and patients with sudoresis, the gaze dressing is the one preferred (26)(27) .

Rev Esc Enferm
As for the adverse events stated in the studies, it was observed that most did not include an evaluation. Although catheter use is an advance in medicine, some factors such as hypersensitivity or anaphylactic reactions, as well as the induction to bacterial resistance and costs, have limited their effective applicability (28)(29) .
Most studies evinced statistically significant differences regarding the reduction in colonization rates in antisepticimpregnated catheters; however, only one study found statistically significant differences for CRBSI rates. According to the authors of the meta-analysis (30) , catheters impregnated with chlorhexidine and silver sulfadiazine are effective in reducing colonization and CRBSI compared to devices without antiseptics, in groups of patients with a high risk for these infections, submitted to short permanence catheterization. Researchers, however, have stressed that the decision of using these devices should take into consideration the potential reduction in morbidity and mortality, lower costs and the risk of adverse effects.
The other meta-analysis (31) did not find any significant odds ratio in the individual evaluation; however, nine of the evaluated studies had a tendency for lower catheterrelated infection rates in the experimental group. They explained that the fact of being impregnated with antiseptic only on the external surface, and having been used for a short period of time could justify the results. Hence, they recommend the elaboration of additional studies to evaluate appropriate culture techniques, which are not influenceable by the action of antiseptics. And, although there were no ideal laboratory methods to diagnose catheter-related infection, there is a need for extra caution in overestimating the results, as well as in explaining the variables, and allocating and masking those involved.
It should be emphasized that in 2002 the CDC recommended using antimicrobial-impregnated CVC in adult patients that required catheterization for more than five days, or in institutions with high rates of infection complications (25) .
Furthermore, other authors have discussed on the potential effects of antiseptic substances used to prepared these catheters, roll plate or sonication techniques; stressing the possibility of inhibiting microbial growth, and recommending the use of neutralizing agents when performing the microbiological analysis, so as to avoid false results (32) .

CONCLUSION
By analyzing the studies, it was concluded that using antiseptic-impregnated central venous catheters reduced microbial colonization in six of the nine evaluated studies. Nevertheless, further studies are called for to investigate the effectiveness of using these catheters in other patient populations and compared to other types of catheters, considering that most of the studies analyzed in the present integrative review did not show statistically significant differences regarding CRBSI rates.