Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds.

BACKGROUND

Non surgical wounds include chronic ulcers (pressure or decubitus ulcers, venous ulcers, diabetic ulcers, ischaemic ulcers), burns and traumatic wounds. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation (i.e. presence of MRSA in the absence of clinical features of infection such as redness or pus discharge) or infection in chronic ulcers varies between 7% and 30%. MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia (infection of the blood) which is associated with a 30-day mortality of about 28% to 38% and a one-year mortality of about 55%. People with non surgical wounds colonised or infected with MRSA may be reservoirs of MRSA, so it is important to treat them, however, we do not know the optimal antibiotic regimen to use in these cases.

OBJECTIVES

To compare the benefits (such as decreased mortality and improved quality of life) and harms (such as adverse events related to antibiotic use) of all antibiotic treatments in people with non surgical wounds with established colonisation or infection caused by MRSA.

SEARCH METHODS

We searched the following databases: The Cochrane Wounds Group Specialised Register (searched 13 March 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2); Database of Abstracts of Reviews of Effects (2013, Issue 2); NHS Economic Evaluation Database (2013, Issue 2); Ovid MEDLINE (1946 to February Week 4 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, March 12, 2013); Ovid EMBASE (1974 to 2013 Week 10); EBSCO CINAHL (1982 to 8 March 2013).

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) comparing antibiotic treatment with no antibiotic treatment or with another antibiotic regimen for the treatment of MRSA-infected non surgical wounds. We included all relevant RCTs in the analysis, irrespective of language, publication status, publication year, or sample size.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials, and extracted data from the trial reports. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing the binary outcomes between the groups and planned to calculate the mean difference (MD) with 95% CI for comparing the continuous outcomes. We planned to perform the meta-analysis using both fixed-effect and random-effects models. We performed intention-to-treat analysis whenever possible.

MAIN RESULTS

We identified three trials that met the inclusion criteria for this review. In these, a total of 47 people with MRSA-positive diabetic foot infections were randomised to six different antibiotic regimens. While these trials included 925 people with multiple pathogens, they reported the information on outcomes for people with MRSA infections separately (MRSA prevalence: 5.1%). The only outcome reported for people with MRSA infection in these trials was the eradication of MRSA. The three trials did not report the review's primary outcomes (death and quality of life) and secondary outcomes (length of hospital stay, use of healthcare resources and time to complete wound healing). Two trials reported serious adverse events in people with infection due to any type of bacteria (i.e. not just MRSA infections), so the proportion of patients with serious adverse events was not available for MRSA-infected wounds. Overall, MRSA was eradicated in 31/47 (66%) of the people included in the three trials, but there were no significant differences in the proportion of people in whom MRSA was eradicated in any of the comparisons, as shown below.1. Daptomycin compared with vancomycin or semisynthetic penicillin: RR of MRSA eradication 1.13; 95% CI 0.56 to 2.25 (14 people).2. Ertapenem compared with piperacillin/tazobactam: RR of MRSA eradication 0.71; 95% CI 0.06 to 9.10 (10 people).3. Moxifloxacin compared with piperacillin/tazobactam followed by amoxycillin/clavulanate: RR of MRSA eradication 0.87; 95% CI 0.56 to 1.36 (23 people).

AUTHORS' CONCLUSIONS: We found no trials comparing the use of antibiotics with no antibiotic for treating MRSA-colonised non-surgical wounds and therefore can draw no conclusions for this population. In the trials that compared different antibiotics for treating MRSA-infected non surgical wounds, there was no evidence that any one antibiotic was better than the others. Further well-designed RCTs are necessary.