This assignment is a critical systematic review of three research articles whereby the aim is to determine whether silver dressings are actually effective in the treatment of Methicillin Resistant Staphylococcus Aureus (MRSA). The aim is also for health care professionals and nurses to enhance and develop an increased knowledge about the effectiveness of silver dressings in the management and treatment of MRSA. The results and findings of the research papers were reviewed, conclusions were drawn and recommendations for future practice were made.

Findings

All three research papers showed clear evidence that silver dressings do have a beneficial effect on the treatment and management of MRSA in practice. The dressing acticoat silver was regarded highly by all the authors of the three reports.

Conclusion

By carrying out this critical systematic review, it is clear that the selection of the appropriate dressing is of great importance in the successful management and treatment of MRSA in wounds. Clinical factors that should be taken into consideration when deciding on the choice of antibacterial dressing are the condition of the wound, the type of wound, the healing and exudate handling effects. It is important to be aware of the of the characteristics and the ways in which silver acts physically as well as chemically, especially when trying to understand the statements made by companies that market silver containing dressings.

Introduction

This critical systematic review is related to a specific aspect of practice and aims to provide research based evidence to answer the following question; how effective is the use of silver dressings in the treatment of Methicillin Resistant Staphylococcus Aureus (MRSA) in wounds?

The increased rate of mortalities relating to health care associated infections (HCAI’s) with MRSA has put increased financial pressure on hospitals (Johnson, 2007). Throughout clinical practice there are alarming concerns of the spread and emergence of MRSA, which is antibiotic resistant. Dow (2001) highlights the fact that within the clinical environment the potential sources of infection are chronic and acute wounds when they become colonised with bacteria (White, 2001). Therefore, can silver dressings really have an impact on MRSA, the so called super bug that is wreaking havoc?

As a result, a systematic review of the relevant published articles will be critiqued using the Santy and Neal (1998) tool, thus confirming the validity, reliability and the ethical implication of the three papers along with the recommendations for future practice.

The three papers critiqued in this systematic review are shown in the table below:

Paper One (Appendix A)

Antimicrobial and barrier effects of silver against MRSA.

Edward-Jones, V (2006).

Paper Two (Appendix B)

Antimicrobial activities of silver dressings, an in vitro comparison.

Maragaret, I, P, Sau, L, L, Vincent, K, Poon , M, Iven, L & Burd, A (2006).

Paper Three (Appendix C)

Silver antimicrobial dressings in wound management, a comparison of antibacterial, physical andchemical characteristics.

Parsons, D, Philip, G, Bowler, M, Myles, V & Jones, S (2005).

Polit et al (2001) has placed emphasis on the fact that data used to solve problems or answer questions is of great importance to the nursing profession and the need for nursing research is beneficial not only to the patients within the clinical environment but to the health professionals also. As nurses are accountable under the Nursing and Midwifery Code of Professional Conduct (NMC, 2008) for the care they provide it is essential for it to be evidence based, so that no harm is inflicted upon the patient (Crow, 1982).

The rationale for this chosen topic is based on treating patients who often find that their chronic wounds have become infected (Dow, 2001). As ever, MRSA burdens the health care service with increasing financial costs and represents an increasing threat to the health and well being of vulnerable patients (Johnson, 2007). Therefore, finding ways through research to effectively treat MRSA can only have positive results and outcomes. MRSA is also a recurring topic under the attention of the media and emphasis is placed upon hospitals when it comes to blame.

As a result, this systematic review also aims to inform and enlighten health care professionals about the effectiveness of the silver dressings in the management and treatment of MRSA in wounds and how vital the selection of the correct dressing is. Another essential aspect is to encourage health care professionals to carry out their own research on the dressings they use and the treatment they provide. The use of silver dressings in wounds is increasingly used for the treatment of contaminated and infected wounds. However, there is a lack of clarity regarding the evidence behind its effectiveness (Vermeulen et al, 2007), hence the purpose of this critical systematic review.

Literature Review

The healing of wounds is a highly complex process as highlighted by Dealey (2005). All wounds are contaminated with bacteria, which Dealey (2005) suggests does not affect healing, however, colonisation occurs when the organisms multiply and progress to infection (Stotts and Whitney, 1999) which does impact upon wound healing. Therefore, this supports the need for healthcare professionals to manage the bacterial load to minimise the risk of infection. Infected wounds can cause prolonged needs for nursing treatment as well as unnecessary pain and in extreme cases can cause death of the patient (Vermeulen et al, 2007).

Staphylococcus aureus is a bacterium found on the skin and in the nose where it resides harmlessly in healthy people, known as colonisation. Although it is usually harmless at these sites, it may occasionally penetrate the body through breaks in the skin such as, abrasions, wounds, cuts, surgical incisions and even indwelling catheters, thus causing infection.

The treatment of infections due to staphylococcus aureus was revolutionised in the 1940’s by the introduction of the antibiotic penicillin. However, most strains of staphylococcus aureus are now resistant to penicillin. This is because staphylococcus aureus can make a substance called B-lactamase, which degrades penicillin, destroying its antibacterial activity. In the early 1960’s, a new type of penicillin antibiotic called methicillin was developed. Methicillin was not degraded by B-lactamase and so could be used to treat infections due to b-lactamase producing strains of staphylococcus aureus. Subsequently, methicillin was replaces by never and better penicillin type antibiotics, such as, flucloxacillin, that were not affected by B-lactamase. Unfortunately, shortly after the introduction of methicillin, certain strains of staphylococcus aureus emerged that were resistant to methicillin (Johnson, 2007), referred to as MRSA.

It is a general agreement that the problem of resistance has been exacerbated by the overuse or misuse of antibiotics so, wherever possible, alternative methods are now required to manage topical infections caused by antibiotic resistant organisms (Thomas, 2004). The knowledge related to the dressings used is a key area of nursing especially in recent times as it is a general agreement that nurse prescribing is on the increase. The choice of dressings and topical agents are not always based on a firm rationale (Lewis et al, 2001).

Topical agents used with dressings to treat wound infection include antibiotics, antiseptics or disinfectants, as these destroy the invading micro organisms or limit their growth. Silver is one of the more popular topical agent added to dressings (Dowsett, 2004).

Nurses should be prepared to objectively evaluate the dressings they use, particularly if they are using new dressings (Dealey, 2005). Many silver dressings available for health care professionals are aquacel ag (Covatec), Acticoat (Smith and Nephew), Urgotul (Urgo) and Contreet (Coloplast). The most frequently observed used products within the authors trust is aquacel Ag and acticoat, therefore, these will be the main dressings that will be reviewed within this systematic review.

Convatec advertise aquacel Ag as the first antimicrobial activity to kill MRSA and other wound pathogens in the dressing.

Smith and Nephew advertise acticoat as a silver dressing, the silver is applied to the polythene mesh by a vapour deposition process, which results in the formation of microscopic nanocrystals of metallic silver. In this nanocrystalline form, metallic silver exhibits pronounced antibacterial activity against a wide range of gram positive and gram negative bacteria including strains resistant to many types of antibiotics. It is also effective against clinically important strains of yeasts and fungi.

Whilst these advertisements have enticed nurses to use the product the evidence to support them may be biased as each company will want their own product to be successful and profitable. As a result, this systematic review aims to demonstrate the efficacy of the product based on valid reliable published evidence.

Methodology

In order to carry out research for articles on silver dressings in the management of MRSA was undertaken using internet based search engines CINAHL (cumulative index to nursing and allied health literature), OVID, Cochrane Library (WILEY), MEDLINE (OVID) and pubmed. To be able to obtain the maximum evidence and consider new products the most up to date and recent evidence resources and materials were utilised even though there was no date limitation applied. In addition to search engines manual reviews of nursing journals and books was also carried out.

Once the appropriate search engine keywords were used such as, silver dressings and MRSA, separately these searches produced 1529 hits. The subjects were then combined to retrieve the appropriate and relevant articles and this resulted in on seven hits. These articles were then considered and reviewed in depth, the abstracts of the seven articles were read thus giving a concise overview of the content in each article. As a result, four of the seven articles did not meet the specifications for this systematic review.

Inclusion Criteria

Exclusion Criteria

The nature of the research is quantitative

The nature of the research being qualitative or comprising case studies.

In vitro comparisons.

Not including acticoat and aquacel Ag.

There were randomised controlled trials.

Papers from untrustworthy and non reputable sources.

MRSA was included along with acticoat and aqaucel Ag.

The use of other micro organisms as well as MRSA.

From a trustworthy and reputable source and written in English.

Findings

The most valuable piece of research evidence, in the opinion of the author is paper one. This is so because the findings from paper one showed that there was no observed growth of either strain of MRSA on the nanocrystalline silver dressings at any of the time phases, demonstrating that both actisorb and aqaucel Ag were acting as effective barriers by preventing the movement of the bacteria. Throughout this paper, data is analysed in depth and presented in the form of tables and images. The tables show the antimicrobial effect of the four different silver dressings at different time periods whereby the images show the growth of the two strains of MRSA (EMRSA-15 and EMRSA-16) on Columbia blood agar plates at one hour and twenty four hours. This was appropriate and necessary in the light of the study and the tables and images were clearly labelled, well organised and easy to understand.

Paper two, on the other hand, found that all the silver dressings that were tested and analysed on nine different bacterial strains including MRSA were effective, especially contreet and acticoat. The nine different strains comprised: (1) staphylococcus aureus, (2) MRSA, (3) enterococcus faecalis, (4) pseudomonas aeruginosa, (5) Escherichia coli, (6) enterobacter cloacae, (7) proteus vulgaris, (8) acinetobacter and (9) baumannii strain (multi drug efflux positive). A measure of each organism was prepared on blood agar plates and kept overnight. Bacteria, was added to each vial containing the silver dressings which was then incubated.

These were shown as exerting maximum bactericidal activity in the reduction of the growth of bacteria at twenty four hours. Interestingly, contreet had the maximal killing effect of MRSA and this was achieved in four hours. The dressings that were tested were aquacel Ag (ConvaTec), aquacel (ConvaTec), acticoat (Smith and Nephew), urgotul (Urgo), Polymem Silver (Ferris) and contreet (Coloplast). These were then transferred into table format and easily understood but the graph representing the bactericidal activities of silver impregnated dressings appears to be somewhat mind boggling and difficult to read and interpret. As there was no clearly identified conclusion nor further recommendations for future practice in this paper, this was another negative aspect of the article.

Paper three also showed each silver dressing that was examined had a degree of antibacterial activity against the wound pathogens that were tested. The favourite of the dressings being aquacel Ag and acticoat. In this study, seven silver containing dressings were assessed against two common wound pathogens which were staphylococcus aureus and pseudomaonas aeruginosa. The seven dressings were (1) aquacel Ag (ConvaTec – referred to as non woven A), (2) acticoat (Smith and Nephew – referred to as non woven B), (3) silvercel (Johnson and Johnson – referred to as non woven C), (4) Contreet (Coloplast – referred to as foam A), (5) polymem silver (Ferris – referred to as foam B), (6) urgotul (Urgo – referred to as gauze and (7) silvasorb (referred to as hydrogel).

The findings of this paper were then presented using numerous graphs and tables which more than supported the design and the hypotheses of the study. However, two of the charts which incorporated a table and a graph were a drawback and unnecessary. They were difficult to follow as a lot of information was cramped in which would have been easily interpreted in the format of a basic graph showing a correlation between the number of surviving bacteria and the time span over seven days. That aside, this paper was thorough and in depth and the analysis of the tests being carried out were understood easily.

Discussion

The three research papers used in this systematic review and have been critiqued are all quantitative research papers. The papers were also in vitro studies and tested the same variable in a similar type of setting, enabling the comparison of the papers as well as any dissimilarities.

The author of paper one has made it clear that a grant for a small amount was given by Smith and Nephew, the manufacturer of one of the dressings that was tested when this study was being carried out. It can be argued that this is sheer bias on the part of the author but the manner in which this study has been conducted makes you believe otherwise.

In order to determine the facts and the truth, quantitative studies are carried out whereby the researchers remove sources of bias in their study or attempt to control the effects of bias once they have been recognised (Burns and Grove, 2001). Many aspects of the research can be biased, for instance, the data collection process, the researcher, the individual subjects, the sample, the measurement tools, the components of the environment in which the study is performed, the data and the statistics and as in the case of paper one, the manufacturer of the silver dressing acticoat has provided a grant for the funding of the study.

Conclusion

By conducting this systematic review, it has become evident that silver is a broad spectrum agent effective against a large number of gram positive and gram negative micro organisms, many aerobes and anaerobes, and several antibiotic resistant strains such as MRSA. Within the last decade, the field of wound care has been inundated with active dressings, especially those that deliver biologically active substances to the wound site.

More than ten different silver containing dressings, including hydrogels, hydrofibers, and alginates, are currently available worldwide. Although all are assumed to be safe and effective, evidence of their efficacy is limited; few clinical trials have been performed with them. Moreover, claims about how the dressings work, how effective the silver in a specific dressing is, and why one dressing is better than the other are based on sometimes scientifically complex methods of testing and results that yield contradictory or inconclusive statements. It is important for health care professionals to be aware of the ways in which silver acts physically and chemically, especially when trying to understand the statements made by companies that market silver containing dressings.

According to the manufacturers of dressings currently available, each enhances wound healing through the antimicrobial activity of silver. However, with many of these dressings, such claims are not based on clinical trials, but rather on case histories and in vitro studies. The use of silver dressings is still in its relative infancy, and as yet the most appropriate use of these materials is not well understood. Although the rapid release of silver may be desirable from a bacteriological point of view, according to Jorgensen (2005), it is important that the silver present in a dressing is not released into the wound in a short period but slowly over a number of days.

Having critiqued the three research articles, the aim is to utilise these findings by making other health care professionals more aware of the benefits of using such silver dressings and encouraging the use of these dressings in future practice. The indications for the use of silver dressings and the choice of specific products depend upon many factors, but the evidence available to date suggests that they have an important role to play in the treatment of infected exuding wounds, including those containing antibiotic resistant strains of bacteria, MRSA. However, further work is required to determine how and where each should be used in order to gain maximum benefit.