Mini-CAT                                                         Name: Ruthie Schreiber

 

 

Clinical Question:

 

44 year old male POD 4, s/p bypass graft presents with a deep incisional surgical site infection along his left lower extremity. On physical exam you notice the wound has reopened and has also produced pus. Upon reviewing his chart you learn that no antimicrobial dressing had been placed, and wonder if this could have easily prevented the infection from occurring.

 

Search Question:

 

In post-operative patients, does using dressing with antimicrobial properties effectively reduce surgical site infections vs. using plain cotton/gauze dressings alone?

 

PICO Question:

 

P	I	C	O
Post-operative patients	Dressings with antimicrobial properties	Cotton dressing	Reduction in surgical site infection
Patients after surgery	Antimicrobial dressing	Gauze dressing	Shorter hospital stay
Adult patients			Morbidity/Mortality

 

 

 

Search tools and strategy used:

 

PubMed

            ~Surgical Site Infection Dressing–> 1154 results

                        *Filter: meta-analysis, systematic review –> 100 results

                                    *Filter: 10 years publication date–> 87 results

            ~Post-operative Patient Dressing–> 1,019 results

                        *Filter: meta-analysis, systematic review–> 19 results

                                    *Filter: 5 years publication date–> 9 results

                                               

Cochrane

            ~ Surgical Site Infection Dressing –> 435 results

                        *Filter: review –>10 results

~Post-operative Patient Dressing –> 342 results

            *Filter: review –> 4 results

 

Google Scholar

            ~Surgical Site Infection Dressing –> 128,000 results

                        *Filter: since 2016 –> 26,000 results

            ~ Post-operative Patient Dressing –> 58,5000 results

                        *Filter: since 2016 –> 18,400 results

 

 

In determining which articles to include for this miniCAT, it was important to find articles that were of the highest evidence available (i.e. systematic review or meta analysis) and to include studies that were conducted recently. I chose to include my specific articles due to their explicit relevance to both my PICO question and clinical scenario. Additionally, these articles feature both meta-analyses as well as systematic reviews, both of which are of high level evidence. Furthermore, these articles were recently published, two within the last 5 years and the last two within the past 10 years, making them pertinent and up to date.

                                   

 

Articles Chosen:

 

1. Dumville JC, Gray TA, Walter CJ, Sharp CA, Page T, Macefield R, Blencowe N, Milne TKG, Reeves BC, Blazeby J. Dressings for the prevention of surgical site infection. Cochrane Database of Systematic Reviews 2016, Issue 12. Art. No.: CD003091. DOI: 10.1002/14651858.CD003091.pub4.

https://www-cochranelibrary-com.york.ezproxy.cuny.edu/cdsr/doi/10.1002/14651858.CD003091.pub4/epdf/full

Background

Surgical wounds (incisions) heal by primary intention when the wound edges are brought together and secured, often with sutures, staples, or clips. Wound dressings applied after wound closure may provide physical support, protection and absorb exudate. There are many different types of wound dressings available and wounds can also be left uncovered (exposed). Surgical site infection (SSI) is a common complication of wounds and this may be associated with using (or not using) dressings, or different types of dressing.

Objectives

To assess the effects of wound dressings compared with no wound dressings, and the effects of alternative wound dressings, in preventing SSIs in surgical wounds healing by primary intention.

Search methods

We searched the following databases: the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In‐Process & Other Non‐Indexed Citations, MEDLINE Daily and Epub Ahead of Print; 1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); EBSCO CINAHL Plus (1937 to 19 September 2016).

There were no restrictions based on language, date of publication or study setting.

Selection criteria

Randomised controlled trials (RCTs) comparing wound dressings with wound exposure (no dressing) or alternative wound dressings for the postoperative management of surgical wounds healing by primary intention.

Data collection and analysis

Two review authors performed study selection, ‘Risk of bias’ assessment and data extraction independently.

Main results

We included 29 trials (5718 participants). All studies except one were at an unclear or high risk of bias. Studies were small, reported low numbers of SSI events and were often not clearly reported. There were 16 trials that included people with wounds resulting from surgical procedures with a ‘clean’ classification, five trials that included people undergoing what was considered ‘clean/contaminated’ surgery, with the remaining studies including people undergoing a variety of surgical procedures with different contamination classifications. Four trials compared wound dressings with no wound dressing (wound exposure); the remaining 25 studies compared alternative dressing types, with the majority comparing a basic wound contact dressing with film dressings, silver dressings or hydrocolloid dressings. The review contains 11 comparisons in total.

Primary outcome: SSI

It is uncertain whether wound exposure or any dressing reduces or increases the risk of SSI compared with alternative options investigated: we assessed the certainty of evidence as very low for most comparisons (and low for others), with downgrading (according to GRADE criteria) largely due to risk of bias and imprecision. We summarise the results of comparisons with meta‐analysed data below:

‐ film dressings compared with basic wound contact dressings following clean surgery (RR 1.34, 95% CI 0.70 to 2.55), very low certainty evidence downgraded once for risk of bias and twice for imprecision.

‐ hydrocolloid dressings compared with basic wound contact dressings following clean surgery (RR 0.91, 95% CI 0.30 to 2.78), very low certainty evidence downgraded once for risk of bias and twice for imprecision.

‐ hydrocolloid dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.57, 95% CI 0.22 to 1.51), very low certainty evidence downgraded twice for risk of bias and twice for imprecision.

‐ silver‐containing dressings compared with basic wound contact dressings following clean surgery (RR 1.11, 95% CI 0.47 to 2.62), very low certainty evidence downgraded once for risk of bias and twice for imprecision.

‐ silver‐containing dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.83, 95% CI 0.51 to 1.37), very low certainty evidence downgraded twice for risk of bias and twice for imprecision.

Secondary outcomes

There was limited and low or very low certainty evidence on secondary outcomes such as scarring, acceptability of dressing and ease of removal, and uncertainty whether wound dressings influenced these outcomes.

Authors’ conclusions

It is uncertain whether covering surgical wounds healing by primary intention with wound dressings reduces the risk of SSI, or whether any particular wound dressing is more effective than others in reducing the risk of SSI, improving scarring, reducing pain, improving acceptability to patients, or is easier to remove. Most studies in this review were small and at a high or unclear risk of bias. Based on the current evidence, decision makers may wish to base decisions about how to dress a wound following surgery on dressing costs as well as patient preference.

 

 

1. In search of the optimal wound dressing material following total hip and knee arthroplasty: a systematic review and meta-analysis Gaurav Sharma1 & Sang Wook Lee & Oliver Atanacio & Javad Parvizi & Tae Kyun Kim

International Orthopaedics (SICOT) (2017) 41:1295–1305 DOI 10.1007/s00264-017-3484-4

https://link-springer-com.york.ezproxy.cuny.edu/content/pdf/10.1007/s00264-017-3484-4.pdf

 

Abstract

Background: Various types of dressing materials are available for wound care following hip and knee arthroplasty. However, it is unclear if one material is more beneficial than the others in terms of wound complications and fluid handling capacity.

Research questions: We performed a meta-analysis of randomized controlled trials comparing alternative wound dressing materials for the post-operative management of wounds following THA and TKA with respect to (1) incidence of wound complications including infection and (2) fluid handling capacity.

Methods: Randomized controlled trials comparing alternative dressing materials, for post-operative management of wounds following TKA and THA were included in the review

Databases searched included the MEDLINE and the EMBASE from inception to February 2017. Two authors performed study selection, risk of bias assessment and data extraction. Where levels of clinical and statistical heterogeneity permitted, data were pooled for meta-analysis.

Results: Twelve randomized trials with data for the primary outcome were identified. Data were available for metaanalysis for two comparisons. Wounds managed with film dressings (odds ratio, 0.35; 95% confidence interval [CI], 0.21–0.57) or with hydrofiber dressings (odds ratio, 0.28; 95% confidence interval [CI], 0.20–0.40) were significantly less likely to have wound complications than those managed with passive dressings. There was no evidence that any dressing significantly reduced surgical-site infection rates compared with any other dressing. Hydrofibre dressings showed better fluid handling capacity than passive dressings in terms of mean number of dressing changes (mean difference 1.36; 95% confidence interval [CI], 0.15–2.57) and number of patients requiring early dressing change (odds ratio, 8.60; 95% confidence interval [CI], 4.68–15.83).

Conclusion: The evidence available in the current literature suggests that advanced dressings such as film and Hydrofibre dressings have fewer wound complications and better fluid handling capacity. However, insufficient evidence is available to determine whether the use of these advanced dressings reduce periprosthetic joint infection.

 

 

 

1. Lee, C. K., Chua, Y. P., & Saw, A. (2012). Antimicrobial gauze as a dressing reduces pin site infection: a randomized controlled trial. Clinical Orthopaedics And Related Research, 470(2), 610-615. doi:10.1007/s11999-011-1990-z

https://link.springer.com/content/pdf/10.1007/s11999-011-1990-z.pdf

 

Abstract

Background: Pin site infection is a common problem in external fixation. Plain gauze wetted with normal saline is commonly used for a pin site dressing owing to the simplicity and low cost. Evidence to support adding an antimicrobial agent in the dressing material is lacking.

Questions/purposes: We compared the rate of pin tract infection using plain gauze and gauze impregnated with polyhexamethylene biguanide in patients undergoing limb lengthening procedures.

Patients and Methods: We included 38 patients (40 limbs) undergoing limb lengthening or deformity correction using an external fixator between July 2009 and June 2010. There were 23 male patients and 15 female patients, with a mean age of 26.3 years (range, 5–68 years). The patients were randomized into two groups: a polyhexamethylene biguanide group (22 limbs) and a control group (18 limbs). The metal-skin interfaces were assessed by a researcher blinded to the type of gauze at 2, 4, 8, and 12 weeks after surgery for the pin site infection based on a predetermined grading system. There were a total of 483 metal-skin interfaces, with 1932 total observations. Infection rates were compared using the chi square test and relative risk with 95% confidence interval.

Results:  The infection rate was lower (v2 [1, n = 1932] = 23.00) and the risk for infection was lower (relative risk, 0.228; 95% confidence interval, 0.118, 0.443) for the polyhexamethylene biguanide group (n = 1068; 1.0%) than for the control group (n = 864; 4.5%).

Conclusions:  Use of polyhexamethylene biguanideimpregnated gauze can reduce the risk of pin tract infection in external fixation.

Level of Evidence Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence

 

 

1. Li HZ, Zhang L, Chen JX, Zheng Y, Zhu XN. Silver-containing dressing for surgical site infection in clean and clean-contaminated operations: a systematic review and meta-analysis of randomized controlled trials. J Surg Res. 2017;215:98–107. doi:10.1016/j.jss.2017.03.040

 

https://www-sciencedirect-com.york.ezproxy.cuny.edu/science/article/pii/S002248041730166X

 

Abstract

Background: Silver-containing dressings for the prevention of surgical site infections (SSIs) remained controversial, and accumulating evidence was lacking, so a meta-analysis was conducted to systematically assess the effectiveness and safety of silver-containing dressings for clean and clean-contaminated surgical incisions.

Methods: Pubmed, Embase, and the Cochrane Library were searched from the inception to February 2016 for randomized controlled trials (RCTs), which explored silver-containing dressings for the prevention of SSIs in clean and clean-contaminated operations. Relative risk (RR) with 95% confidence interval (CI) was pooled using random effects model. Predefined subgroup analyses, sensitivity analyses, and influence analyses were further undertaken.

Results: Nine RCTs totaling 2196 patients (1141 in silver-containing group and 1055 in control group) were included. Silver-containing dressings did not effectively prevent the incidence of SSIs (9 RCTs; RR: 0.92; 95% CI: 0.66-1.29; I² = 40%), superficial SSIs (5 RCTs; RR: 0.67; 95% CI: 0.36-1.24; I² = 36%), and deep SSIs (5 RCTs; RR: 0.78; 95% CI: 0.41-1.49; I² = 0). Subgroup analyses, sensitivity analyses, and influence analyses confirmed the robustness of the pooled estimate.

Conclusions: The current available evidence indicated that silver-containing dressing as compared with silver-free dressing was not associated with lower incidence of SSIs. Considering the quality of evidence ranking very low, further studies with higher quality should be warranted.

 

Summary of the Evidence:

Author (Date)	Level of Evidence	Sample/Setting (# of subjects/ studies, cohort definition etc. )	Outcome(s) studied	Key Findings	Limitations and Biases
Dumville JC, Gray TA, Walter CJ, Sharp CA, Page T, Macefield R, Blencowe N, Milne TKG, Reeves BC, Blazeby J. (2016)	Systematic Review	-The following databases were searched for this study: the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations, MEDLINE Daily and Epub Ahead of Print; 1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); EBSCO CINAHL Plus (1937 to 19 September 2016). -29 randomized controlled studies were included that investigated the use of dressings in both surgeries with low and high risk of surgical site infections. -These studies compared wound dressings with wound exposure (i.e. no dressing) or alternative wound dressings for post-operative management of surgical wounds to heal by primary intention	-The goal of this review was to determine which type of wound dressing had the best impact on reducing post-surgical site infections, less pain/scarring, and generalized overall outcome.	-Ultimately 29 trials of 5718 participants were included, resulting in 11 comparisons total. The following evidence was obtained regarding the primary outcome of surgical site infection: – Film dressings compared with basic wound contact dressings following clean surgery (RR 1.34, 95% CI 0.70 to 2.55), very low certainty evidence downgraded once for risk of bias and twice for imprecision. -Hydrocolloid dressings compared with basic wound contact dressings following clean surgery (RR 0.91, 95% CI 0.30 to 2.78), very low certainty evidence downgraded once for risk of bias and twice for imprecision. -Hydrocolloid dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.57, 95% CI 0.22 to 1.51), very low certainty evidence downgraded twice for risk of bias and twice for imprecision. -Silver-containing dressings compared with basic wound contact dressings following clean surgery (RR 1.11, 95% CI 0.47 to 2.62), very low certainty evidence downgraded once for risk of bias and twice for imprecision. -Silver-containing dressings compared with basic wound contact dressings following potentially contaminated surgery (RR 0.83, 95% CI 0.51 to 1.37), very low certainty evidence downgraded twice for risk of bias and twice for imprecision.	-The authors recognized the limitations in their study and the high risk of potential bias. Their main results indicate that the certainty of their evidence was very low, and that there was a large risk of bias and imprecision -In their conclusion this point is highlighted once again, reiterating to the reader that most studies included in the review were small and that there was either a high or unclear risk of bias
Gaurav Sharma & Sang Wook Lee & Oliver Atanacio & Javad Parvizi & Tae Kyun Kim (2017)	Systematic Review & Meta Analysis	-PubMed and EMBASE databases were searched in February 2017 using the following search terms: (dressing or post-operative dressing or wound dressing) and (knee arthroplasty or hip arthroplasty or knee replacement or hip replacement or lower limb arthroplasty)   -12 randomized controlled trials were included in this review which met the inclusion criteria that all investigated whether or not choice of dressing material affects wound complication rate following total hip/ total knee arthroplasty	-The goal of review was to determine which wound dressing material would be best for management of post-operative wounds specifically following total hip and knee arthroplasty.   -The primary outcome measures were composite wound complication (i.e. blister, erythema, maceration, leakage) and surgical site infection.   -The secondary outcome measure was fluid handling capacity (wear time in days, or mean number of dressing changes, or % of patients requiring early dressing change)	-Wounds managed with film dressings (odds ratio, 0.35; 95% confidence interval [CI], 0.21–0.57) or with hydrofiber dressings (odds ratio, 0.28; 95% confidence interval [CI], 0.20–0.40) were significantly less likely to have wound complications than those managed with passive dressings. -There was no evidence that any dressing significantly reduced surgical-site infection rates compared with any other dressing. -Hydrofiber dressings showed better fluid handling capacity than passive dressings in terms of mean number of dressing changes (mean difference 1.36; 95% confidence interval [CI], 0.15–2.57) and number of patients requiring early dressing change (odds ratio, 8.60; 95% confidence interval [CI], 4.68–15.83).	-Even though all included studies were randomized controlled trials, concealment of allocation was unclear in six of those trials   -Additionally no study was double blind, and the outcome assessors were only blind in 1 study   -Attrition bias was low in all studies (due to small duration of follow up)
Lee, C. K., Chua, Y. P., & Saw, A. (2012).	Randomized Controlled Trial	-38 patients were included in this RCT who were undergoing either limb lengthening or deformity correction using an external fixator (all between July 2009-June 2010)   -23 male patients and 15 female patients with a mean age of 26.3 years were included for a total of 40 limbs being investigated.   -Patients were randomized into either polyhemaxethylene biguanide group (22 limbs) or a control group (18 limbs)   –There was a total of 483 metal-skin interfaces, with 1932 observations	-The goal of this study was to compare the rate of pin tract infection using plain gauze vs. gauze impregnate with polyhemaxethylene biguanide in patients underoing limb procedures	-Infection rates were compared using chi square test and relative risk with 95% confidence interval -The infection rate was lower (v2 [1, n = 1932] = 23.00) and the risk for infection was lower (relative risk, 0.228; 95% confidence interval, 0.118, 0.443) for the polyhexamethylene biguanide group (n = 1068; 1.0%) than for the control group (n = 864; 4.5%).	-The authors recognize that their study was designed to look for infection rate per number of observations rather than per number of pin sites or per patient.
Li HZ, Zhang L, Chen JX, Zheng Y, Zhu XN (2017)	Systematic Review & Meta Analysis	-PubMED, EMBASE, & Cochrane Library were searched for randomized controlled trials exploring silver-containing dressings for prevention of surgical site infections in both clean and clean-contaminated operations.   -Relative risk (RR) with 95% confidence interval (CI) was pooled using random effects model.   -9 randomized controlled trials totaling 2196 patients were included (1141 in the silver-containing group and 1055 in the control group).	-The goal of this review was to assess the effectiveness and safety of silver-containing dressings for clean as well as clean-contaminated surgical incisions	-Silver-containing dressings did not effectively prevent the incidence of SSIs (9 RCTs; RR: 0.92; 95% CI: 0.66-1.29; I2 1⁄4 40%), superficial SSIs (5 RCTs; RR: 0.67; 95% CI: 0.36-1.24; I2 1⁄4 36%), and deep SSIs (5 RCTs; RR: 0.78; 95% CI: 0.41-1.49; I2 1⁄4 0).	-All included studies had inherent clinical differences in demographic characteristics, silver-containing products, pathogens adhered to surgical incisions, etc. -Quality of evidence for surgical site infections was deemed as very low (medium-level heterogeneity (I2 1⁄4 40%). -Limited data available on post-surgical wound healing, patient satisfaction, hospital costs, and quality of life associated with silver-containing dressings

 

Conclusion(s):

 

Article #1:  Dumville JC et al concluded that no concrete evidence was found that suggests the preference of one type of dressing over the other. Additionally, there was limited and low evidence on scarring, acceptability of dressing, as well as ease of removal. However, the research is still beneficial as it sets the foundation for future studies to determine how to best dress a wound for a post-surgical patient.

 

Article #2: Gaurav Sharma et al concluded that advanced dressings (i.e. film dressings, hydrofiber dressings) are significantly less likely to develop complications (i.e. blisters, redness) than those managed with gauze based dressings. Additionally, these advanced dressings have better fluid handling capacity. There was insufficient evidence from this study to determine whether these advanced dressings reduce the incidence of post-surgical joint infection (periprosthetic joint infection in particular).

 

Article #3: Lee, C. K et al concluded that the use of polyhexamethylene biguanide impregnant gauze does in fact reduce the risk of infection in patients who are s/p external fixation.

 

Article #4: Chen JX et al concluded that silver-containing dressing was not associated with lower incidence of surgical site infections when compared to silver-free dressing. However, it should be noted that the quality of this evidence ranks low and warrants future studies with higher quality evidence.

 

My overall conclusion for this mini-CAT assignment is that dressings with antimicrobial properties are moderately more effective than use of simple (i.e. gauze/cotton) dressings in preventing surgical site complications. Silver dressings however were not proven to have lower rate of surgical site infections, and therefore can not be included in this overarching conclusion. It is acceptable to conclude from this research that there is clear benefit to using the other advanced dressings in post-operative patients. Having said that, future studies should still be conducted to include larger sample sizes, and feature the most common dressings used by surgeons to yield highly informative and evidence based results.

 

Clinical Bottom Line:

 

I weigh my studies in the following order:

1. Article #2: Gaurav Sharma et al
2. Article #4: Chen JX et al
3. Article #1: Dumville JC et al
4. Article #3: Lee, C. K et al

 

 

Gaurav Sharma et al was the highest level of evidence since it was a systematic review as well as a meta-analysis and it was published in 2017. It also included 12 randomized controlled trials and featured film dressings, hydrofiber dressings, as well as passive dressings. Another advantage of this article was that it assessed both incidence of wound complications (i.e. infection) as well as fluid handling capacity of the dressing itself.

 

Chen JX et al was also at the highest level of evidence since it was a systematic review as well as a meta-analysis, also published in 2017. This article focused on silver-containing dressings as prevention for surgical site infections which I appreciated due to its controversial nature. This article indicates how silver-containing dressing is not actually associated with lower incidence of surgical site infections, leading the reader to choose an alternative non-silver containing dressing when given the option.

 

Dumville JC et al was also at the highest level of evidence as it was a systematic review published in 2016. It received a lower ranking though since the authors explicitly acknowledged that the certainty of their evidence was very low, and that there was a large risk of bias and imprecision.

 

Lee, C. K et al was ranked lowest due to its level of evidence (randomized controlled trial) and its publication year of 2012. This article does show the benefit of using polyhexamethylene biguanide impregnant gauze. However, since this was an RCT featuring 38 patients undergoing either limb lengthening or deformity correction using an external fixator it is difficult to apply this evidence in a broader sense. Larger future studies would be warranted to better support using this specific dressing for post-surgical patients.

 

Magnitude of any effects:

I do believe that the effect of using antimicrobial dressings in post-surgical patients is moderately greater than the effect of using a simple cotton/gauze dressing by reducing risk of surgical site infection.

 

Clinical Significance:

Overall the research clearly indicates that use of advanced dressing is somewhat beneficial for post-operative patients. These results are significant because it would potentially reduce the number of surgical site infections seen in post-operative patients with the knowledge acquired from this assignment. It would certainly be a waste of resources to require post-surgical patients to have advanced dressings if there was no proven benefit to doing so. However, since there is evidence based research that does support the use of such advanced dressings, it justifies obtaining them despite extra cost.

 

Any other considerations important in weighing this evidence to guide practice:

 

Future studies are certainly warranted and should be conducted. Elements that should be addressed include: larger sample sizes as well as featuring the most common dressings used by surgeons. In doing so, the research can yield highly informative and evidence based information for the medical community. In the meantime, it is recommended that practitioners choose dressings based on other factors such as cost, clinician/patient preferences, while keeping in mind the clear benefit of anti-microbial properties.