Introduction

An ‘aseptic’ non-touch dressing technique is conventional and has been assumed to promote healing and prevent infection. As a consequence, it has been the gold standard for many years in the management of postoperative surgical wounds. This technique aims to prevent microorganisms on hands, surfaces and equipment from being introduced into the wound. When considering SSI incidence, it has to be asked whether there is a difference between the non-touch dressing technique and the less expensive clean dressing technique. The purpose of the review was to determine the clinical effectiveness of clean rather than non-touch dressing changing techniques for the prevention of SSI.

Overview of evidence

A single RCT was identified.

A small pilot RCT²¹¹ (n = 30 participants) compared clean with non-touch dressing change techniques in the management of post-surgical wounds healing by secondary intention. [EL = 1−] The primary outcome was wound healing defined as a reduction in the wound volume. Participants were patients who had undergone elective gastrointestinal operations and who presented wounds healing by secondary intention. The trial found no statistically significant difference between the two groups (weighted mean difference -3.80 cm³, 95% CI -9.96 to 2.36) (Figure 7.1). However, the follow-up was only 4 days.

Figure 7.1

Comparison of the effect on SSI incidence of clean versus non-touch dressing change techniques for management of wounds healing by secondary intention.

Evidence statement

There was insufficient evidence from a pilot study to show whether there is a significant difference in the rate of wound healing for a clean compared with an aseptic non-touch dressing change technique for healing by secondary intention. [EL = 1−]

GDG interpretation

There is no high-quality evidence available that supports a change to the current clinical practice of using an aseptic non-touch technique. However, the GDG agreed that aseptic non-touch techniques for removing or changing surgical wound dressings can minimise the risk of contaminating the site with additional microorganisms.

Introduction

The cleansing of surgical wounds with sterile saline solution is a common practice among healthcare practitioners (see Appendix I). As well as improving patient wellbeing, the practice is used to remove excess wound exudate or any mobile slough and wound debris. However, the impact this practice might have on SSIs needs more consideration. The purpose of the review was to examine the clinical and cost-effectiveness of using wound cleansing solutions for prevention of SSI in wounds healing by primary and secondary intention.

Overview of evidence

Health economics overview of evidence

One study from a Cochrane review was included.

An RCT²¹³ compared the effect of cleansing a wound with saline solution against cleansing a wound with tap water on the incidence of wound infection. Participants were patients with acute traumatic or chronic wounds. Since there was no difference in the incidence of wound infection between the two groups, a cost-minimisation analysis needed to be carried out showing that tap water was less expensive than normal saline.

Health economics evidence statement

The price in the British National Formulary (BNF)¹⁰⁷ for sodium chloride solution (0.9%) as a skin cleanser was 95p for 1 litre.

Evidence statements

There was no evidence available that examined the effects of wound cleansing solutions for the prevention of SSI.

Two quasi-randomised studies showed no evidence of a difference between showering or not showering to prevent SSI. [EL = 1+]

GDG interpretation

There appeared to be no obvious difference between showering and not showering in terms of the incidence of SSI.

The GDG consensus was that only sterile cleansing solutions should be applied in the immediate postoperative period. However, where a surgical incision has separated or has been surgically opened to drain pus, several days after surgery, then the use of tap water may be considered for wound cleansing.

There is no evidence to show that postoperative showering during the hospital stay affects the rate of SSI. Therefore, patients can choose to shower safely according to local protocols.

Introduction

The use of topical antibiotics in wound healing by secondary intention is questionable because of the risks of unknown absorption and toxicity, allergy and antimicrobial resistance. Antiseptics have an established important role in chronic wound care, for example chlorhexidine (and other related compounds) and povidone-iodine with other antiseptics such as silver and even honey.

Overview of evidence

One RCT was identified.

A single RCT²¹⁴ (n = 92 participants) examined the effect on the prevention of SSI when applying a topical antimicrobial to the surgical wound. [EL = 1+] Patients underwent orthopaedic surgical procedures following a fractured neck of the femur. The outcome considered was SSI. The antimicrobial used was a chloramphenicol ointment applied to the incisional site at the end of the procedure and at the third day postoperatively. The trial found no statistically significant difference between the two groups (OR 0.43, 95% CI 0.12 to 1.54) (Figure 7.2).

Figure 7.2

Comparison of the effect on SSI incidence of topical chloramphenicol ointment application to the surgical wound versus no application.

Evidence statement

There is evidence from a single RCT to suggest that there is no difference in the incidence of SSI when applying chloramphenicol to the incisional site in the postoperative period. [EL = 1+]

GDG interpretation

There is insufficient evidence from one underpowered study to show any benefit of using topically applied chloramphenicol to prevent SSI.

Introduction

This section updates recommendations within the NICE Technology Appraisal 24: ‘Guidance on the use of debriding agents and specialist wound care clinics for difficult to heal surgical wounds’.

There are many types of antimicrobials and antimicrobial-impregnated dressings available for the management of surgical wounds healing by secondary intention. The efficacy of these dressings and topical agents has been considered in this review.

Overview of the evidence

Four RCTs were identified.

Four trials^215–218 (n = 226 participants) investigated the effect on wound healing when using various types of dressing, with or without topical solutions, in post-surgical wounds healing by secondary intention. [EL = 1−] Participants were patients with surgical wounds left open to heal by secondary intention. The outcome of interest reported in the studies was wound healing expressed as time to complete healing, time to a clean wound, proportion of wounds healed during follow-up or wound size reduction. Definitions used varied among the studies.

Sodium hypochlorite-soaked gauze plus combine dressing pad compared with combine dressing pad compared with alginate dressing

One RCT²¹⁵ (n = 36) compared the use of a gauze soaked with sodium hypochlorite plus a combine dressing pad with the use of a combine dressing pad alone and with the use of an alginate dressing. [EL = 1−] The study included post-surgical abdominal wounds that had presented with a breakdown and followed size reduction of the wounds (surface and volume) for the three different groups. The trial found no statistically significant difference in the wound size reduction between the sodium hypochlorite gauze group and the alginate dressing group (Figures 7.3 and 7.4). It found, however, that the wound size reduction appeared to be significantly greater when using the combine dressing pad against the use of the sodium hypochlorite-soaked gauze or alginate dressing (Figures 7.5 and 7.6).

Figure 7.3

Comparison of the reduction of the wound area using sodium hypochlorite-soaked gauze and a combine dressing pad versus alginate dressing for management of wounds healing by secondary intention.

Figure 7.4

Comparison of the reduction of the wound volume using sodium hypochlorite-soaked gauze and a combine dressing pad versus alginate dressing for management of wounds healing by secondary intention.

Figure 7.5

Comparison of the reduction of the wound area using sodium hypochlorite-soaked gauze and a combine dressing pad versus combine dressing pad for management of wounds healing by secondary intention.

Figure 7.6

Comparison of the reduction of the wound volume using sodium hypochlorite-soaked gauze and a combine dressing pad versus combine dressing pad for management of wounds healing by secondary intention.

Gauze packing soaked with saline compared with calcium alginate cavity pack

One RCT²¹⁸ (n = 34 participants) explored the use of alginate dressings for incised abscess cavities compared with saline-soaked gauze packs. [EL = 1−] Wound healing was expressed as the proportion of patients with a completely healed wound after 2 weeks. It was found that the proportion of wounds healed was higher among the patients that received the saline-soaked gauze dressing but the result was not statistically significant (Figure 7.7).

Figure 7.7

Comparison of wound healing rates using alginate dressings for incised abscess cavities versus saline-soaked gauze packs.

Evidence statements

There is insufficient high quality evidence to suggest any difference in the wound size reduction of surgical wounds healing by secondary intention when comparing the use of gauze with sodium hypochlorite with the use of a combine dressing pad or with the use of alginate dressing. [EL = 1−]

There is insufficient high quality evidence to suggest any difference in healing rates when comparing the use of silicone foam dressings with the use of ribbon gauze soaked in mercuric antiseptic solution in the healing process of open surgical wounds. [EL = 1−]

There is insufficient evidence to determine whether there is any difference in the healing process of post-surgical open wounds in patients presenting with abscesses when comparing the use of moist cotton gauze with polyurethane foam with the use of hydroactive particles dressings or when comparing the use of gauze packing with saline with the use of alginate cavity packs. [EL = 1−]

GDG interpretation

Many of the trials identified are old and most of the materials used do not reflect the underlying principles of current wound management and may have a detrimental effect on the patient’s experience (for example, pain).

A number of new dressings containing antimicrobials, such as honey, silver and cadexomer iodine, are now available and may be clinically appropriate. However, to date, there is no evidence to prove their efficacy in prophylaxis of SSI and further studies to prove their worth in treatment are needed (see Appendix C).

Introduction

Not all SSIs require antibiotic treatment: minor infections may respond to drainage of pus (for example, by removal of sutures) and topical antisepsis. Antibiotic therapy carries with it the risk of adverse drug reactions and the development of resistant bacteria with the associated risk of C. difficile diarrhoea.

GDG consensus of good practice

Microbiological cultures (of swabs and/or samples of pus) should be sought from clinically serious infections, when patients are hypersensitive to first-line antibiotics and when antibiotic-resistant pathogens are suspected, for example in recent hospital inpatients or those returning from travel to countries with high rates of antimicrobial-resistant pathogens. The choice of second-line antibiotics is limited in such patients, and culture results can guide therapy should initial treatment fail.

First-line antibiotic therapy (‘empirical’ or ‘blind’ therapy) should cover the most likely infecting pathogens, the patient’s clinical status – including recent antibiotic history and microbiology – and local antibiotic resistance patterns. Empirical therapy should be broad-spectrum and cover S. aureus, which is the most common cause of SSI after all types of operation.

SSIs after clean-contaminated surgery that involves mucosal surfaces should be treated with an empirical antibiotic regimen that includes activity against anaerobic bacteria (for example, metronidazole, co-amoxiclav, piperacillin-tazobactam or meropenem).

SSIs in patients known to have, or be at risk of meticillin-resistant S. aureus (MRSA) carriage should be treated with an empirical antibiotic regimen that includes activity against locally prevalent strains of MRSA.

All antibiotic therapy should be reviewed in the light of their clinical progress after culture results have been reported.

Recommendations for first- and second-line antibiotic therapy of SSI should be included in local hospital and community antibiotic prescribing guidelines and be consistent with local antibiotic formularies. These guidelines should include advice about special patient groups (for example, patients who are at higher risk locally of being carriers of resistant bacteria such as MRSA) and about particular organisms associated with SSI after specific and common types of surgical operation.

Antibiotic treatment guidelines should be reviewed regularly by microbiologists and, where appropriate, infectious diseases specialists (IDS) in response to local antibiotic sensitivity prevalence data. Microbiologists and IDS should also be available to provide expert advice for individual patients if indicated.

In the event of treatment failure, the patient should be reviewed clinically for evidence of non-infective reasons for wound breakdown, such as poor nutrition or underlying surgical problems (for example, a collection of pus, an anastomotic leak or a foreign body). It is imperative that the results of samples sent for microbiology are reviewed as soon as they are available and further samples obtained if required.

If, based on the microbiology results, a change of antibiotic is considered, it should cover a different spectrum of pathogens from the antibiotic treatment used previously.

GDG interpretation

As no systematic searches were conducted for this section of the guideline, the GDG’s recommendations are based on its consensus view reflecting good practice in the antibiotic treatment of SSIs.

Introduction

This section updates recommendations within the NICE Technology Appraisal 24: ‘Guidance on the use of debriding agents and specialist wound care clinics for difficult to heal surgical wounds’.

The presence of dead (necrotic) or damaged (slough) tissue within a surgical wound healing by secondary intention almost certainly delays healing. Necrotic material or slough within the wound margin acts as a medium for bacterial proliferation and therefore should be removed (the process of debridement – see the Glossary of terms).

Most data from trials of dressings involve the management of chronic wounds, such as diabetic and venous leg and pressure ulcers healing by secondary intention. In general, data from chronic wound healing studies cannot be readily applied to surgical wounds healing by secondary intention (for example, where the wound edges have separated, owing to other confounding factors such as the patient’s comorbidity, the presence of infection, or when the incision has electively been left open to heal by secondary intention because of severe intraoperative contamination as described previously). In this review, the clinical effect of various debridement techniques for the prevention and management of SSI was investigated.

Overview of evidence

Four RCTs were identified.^219–222

Evidence statements

There is insufficient evidence to decide whether there is an effect on the healing of postoperative open and infected wounds when comparing dextranomer beads treatment with Eusol gauze dressing. [EL = 1−]

The evidence from a small RCT suggesting that foam dressings favour the healing of postoperative open wounds when compared with dextranomer dressings is insufficient. [EL = 1−]

There is insufficient evidence to decide whether there is an effect on the healing of postoperative infected wounds when comparing dextranomer paste with polyvinylpyrrolidone 10%. [EL = 1−]

The evidence from a small RCT suggesting that enzymatic dressings (streptodornase/streptokinase) favour the healing of postoperative wounds when compared with saline-soaked dressings is insufficient. [EL = 1−]

GDG interpretation

Many of the trials identified are old and the materials used do not reflect the underlying principles of modern wound management and debridement techniques, and are no longer routinely used.