Topical antibiotics for preventing surgical site infection in wounds healing by primary intention

BACKGROUND

Surgical site infections (SSI) can delay wound healing, impair cosmetic outcome and increase healthcare costs. Topical antibiotics are sometimes used to reduce microbial contaminant exposure following surgical procedures, with the aim of reducing SSIs.

OBJECTIVES

The primary objective of this review was to determine whether the application of topical antibiotics to surgical wounds that are healing by primary intention reduces the incidence of SSI and whether it increases the incidence of adverse outcomes (allergic contact dermatitis, infections with patterns of antibiotic resistance and anaphylaxis).

SEARCH METHODS

In May 2015 we searched: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL. We also searched clinical trial registries for ongoing studies, and bibliographies of relevant publications to identify further eligible trials. There was no restriction of language, date of study or setting. The search was repeated in May 2016 to ensure currency of included studies.

SELECTION CRITERIA

All randomized controlled trials (RCTs) and quasi-randomised trials that assessed the effects of topical antibiotics (any formulation, including impregnated dressings) in people with surgical wounds healing by primary intention were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and independently extracted data. Two authors then assessed the studies for risk of bias. Risk ratios were calculated for dichotomous variables, and when a sufficient number of comparable trials were available, trials were pooled in a meta-analysis.

MAIN RESULTS

A total of 10 RCTs and four quasi-randomised trials with 6466 participants met the inclusion criteria. Six studies involved minor procedures conducted in an outpatient or emergency department setting; eight studies involved major surgery conducted in theatre. Nine different topical antibiotics were included. We included two three-arm trials, two four-arm trials and 10 two-arm trials. The control groups comprised; an alternative topical antibiotic (two studies), topical antiseptic (six studies) and no topical antibiotic (10 studies), which comprised inert ointment (five studies) no treatment (four studies) and one study with one arm of each.The risk of bias of the 14 studies varied. Seven studies were at high risk of bias, five at unclear risk of bias and two at low risk of bias. Most risk of bias concerned risk of selection bias.Twelve of the studies (6259 participants) reported infection rates, although we could not extract the data for this outcome from one study. Four studies (3334 participants) measured allergic contact dermatitis as an outcome. Four studies measured positive wound swabs for patterns of antimicrobial resistance, for which there were no outcomes reported. No episodes of anaphylaxis were reported. Topical antibiotic versus no topical antibioticWe pooled the results of eight trials (5427 participants) for the outcome of SSI. Topical antibiotics probably reduce the risk of SSI in people with surgical wounds healing by primary intention compared with no topical antibiotic (RR 0.61, 95% CI 0.42 to 0.87; moderate-quality evidence downgraded once for risk of bias). This equates to 20 fewer SSIs per 1000 patients treated with topical antibiotics (95% CI 7 to 29) and a number needed to treat for one additional beneficial outcome (NNTB) (i.e. prevention of one SSI) of 50.We pooled the results of three trials (3012 participants) for the outcome of allergic contact dermatitis, however this comparison was underpowered, and it is unclear whether topical antibiotics affect the risk of allergic contact dermatitis (RR 3.94, 95% CI 0.46 to 34.00; very low-quality evidence, downgraded twice for risk of bias, once for imprecision). Topical antibiotic versus antiseptic We pooled the results of five trials (1299 participants) for the outcome of SSI. Topical antibiotics probably reduce the risk of SSI in people with surgical wounds healing by primary intention compared with using topical antiseptics (RR 0.49, 95% CI 0.30 to 0.80; moderate-quality evidence downgraded once for risk of bias). This equates to 43 fewer SSIs per 1000 patients treated with topical antibiotics instead of antiseptics (95% CI 17 to 59) and an NNTB of 24.We pooled the results of two trials (541 participants) for the outcome of allergic contact dermatitis; there was no clear difference in the risk of dermatitis between topical antibiotics and antiseptics, however this comparison was underpowered and a difference cannot be ruled out (RR 0.97, 95% CI 0.52 to 1.82; very low-quality evidence, downgraded twice for risk of bias and once for imprecision). Topical antibiotic versus topical antibioticOne study (99 participants) compared mupirocin ointment with a combination ointment of neomycin/polymyxin B/bacitracin zinc for the outcome of SSI. There was no clear difference in the risk of SSI, however this comparison was underpowered (very low-quality evidence downgraded twice for risk of bias, once for imprecision).A four-arm trial involved two antibiotic arms (neomycin sulfate/bacitracin zinc/polymyxin B sulphate combination ointment versus bacitracin zinc, 219 participants). There was no clear difference in risk of SSI between the combination ointment and the bacitracin zinc ointment. The quality of evidence for this outcome was low, downgraded once for risk of bias, and once for imprecision.

AUTHORS' CONCLUSIONS

Topical antibiotics applied to surgical wounds healing by primary intention probably reduce the risk of SSI relative to no antibiotic, and relative to topical antiseptics (moderate quality evidence). We are unable to draw conclusions regarding the effects of topical antibiotics on adverse outcomes such as allergic contact dermatitis due to lack of statistical power (small sample sizes). We are also unable to draw conclusions regarding the impact of increasing topical antibiotic use on antibiotic resistance. The relative effects of different topical antibiotics are unclear.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentrations at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications for these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentrations at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications for these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.

Update on the Use of Antibiotics in Cutaneous Surgery

BACKGROUND

Antibiotics are often prescribed in perioperative settings, including dermatologic surgery. Given the continued evolution in the breadth and complexity of cutaneous procedures performed and inevitable localized or distant infections that occasionally occur, it seems prudent to periodically evaluate findings and recommendations from the literature regarding the use of antibiotics in cutaneous surgery.

MATERIALS AND METHODS

Literature review from English-language sources from the past 30 years, especially focusing on sources from the past 5 to 10 years. Data were examined for a variety of cutaneous surgical procedures, routes of antibiotic administration, and consideration of both cutaneous and distant infections.

RESULTS

The literature suggests that, for most routine skin procedures, antibiotic use is probably not warranted for the prevention of surgical wound infection, endocarditis, and late prosthetic joint infections. During prolonged Mohs procedures, delayed repairs, grafts, takedowns of interpolation flaps, or any procedure that breaches a mucosal surface, the evidence is less clear, and decisions should be made on a case-by-case basis. Topical antibiotics are probably overused, although silver sulfadiazine may have an undeserved negative reputation among dermatologists. Systemic prophylactic antibiotics for laser resurfacing and liposuction appear not to be routinely necessary, although patients with known prior herpes infection likely should receive antiviral prophylaxis. The overall reported infection rates and infectious complications remain low in dermatologic surgery, and antibiotic therapy may be prescribed excessively or inappropriately as a result. CONCLUSION.: Antibiotics continue to be widely used, and through varying routes of administration, in the setting of dermatologic surgery. Prudent use of these agents is indicated in high-risk patients, certain anatomic locations, and the presence of overt infection. Additional studies may help clarify the most appropriate indications, and in which patient populations, in the future.

Topical antibacterial agents

Decreased systemic toxicity, ease of application, and increased concentration at the target site are some of the important advantages topical antibacterial agents offer. This article reviews the literature on selected indications of these agents and provides in-depth examination of specific agents for the prophylaxis and treatment of skin and wound infections.

Topical antibacterial agents

Topical antibacterial agents occupy an important niche of antimicrobial therapy for both inpatients and outpatients. These agents, including antiseptic and antibiotic preparations, are used for prophylaxis and treatment of infection. Prophylactic uses include application for traumatic and surgical wounds, burns, intravascular catheters, and eradication of S. aureus nasal carriage. Topical antibacterial agents are also used for treatment of primary and secondary pyodermas. Individual antibacterial agents have been reviewed. Of note, despite the widespread use of topical antibacterial agents, further data on which to guide therapy are needed in many instances.

Dressing the part

Wound care after cutaneous surgery can play an integral role in wound healing. Wound care regimens have changed dramatically over the last 35 years as the physiology of wound healing has become better understood. Foremost is the improvement in wound healing achieved by keeping the wound occluded and moist. This observation has led to an explosion of a whole new category of occlusive dressings at the surgeon's disposal in healing postoperative wounds. These dressings have numerous applications as discussed previously. Generally, for acute surgical wounds, occlusive dressings are most useful for split-thickness wounds, such as graft donor sites and after dermabrasion, chemical peel, or laser treatment, and full-thickness wounds allowed to heal by secondary intention. Occlusive dressings may have greater benefit for the treatment of chronic ulcers of varying etiologies. The different categories of dressings share the common disadvantage of being relatively expensive. For routine sutured wounds, the authors prefer the readily available and inexpensive Telfa-type dressing combined with a topical antibiotic ointment. Topical antiseptics are useful for reducing bacterial counts on intact skin in preparation for surgery. Povidone-iodine (Betadine) and chlorhexidine gluconate (Hibiclens) have emerged as the two agents of choice. However, antiseptics have been shown to be toxic to healing tissue, and should not be used on open wounds. In contrast, topical antibiotic ointments are safe to use on open wounds, effective in preventing wound infections, and promote wound healing by maintaining a moist wound environment. The authors prefer the combination antibiotic ointment Polysporin for routine postoperative wound care. Antibiotic prophylaxis in dermatologic surgery to prevent wound infection is appropriate in certain cases. Surgery performed on grossly contaminated or infected skin requires a full 7 to 10 day course of antibiotics. Procedures in anatomic areas considered contaminated as well as in clean areas with significant environmental or patient risk factors may benefit from antibiotic prophylaxis. The choice of antibiotics should be based on the organism most likely to cause wound infection at the particular surgical site. Evidence supports giving a single preoperative dose 1 hour before surgery with a second dose possible 6 hours later if the procedure is prolonged or delayed. The risk of bacterial endocarditis after dermatologic surgery is not known. Antibiotics are indicated for any procedure on obviously infected skin, but are not routinely required for very minor procedures, such as small biopsies, on intact skin. Antibiotic prophylaxis may be prudent for those patients classified as high risk by the (AHA). The antibiotic chosen should again cover the organism most likely to cause infection. One dose can be given 1 hour before surgery and repeated 6 hours postoperatively. Finally, wound healing can be greatly impacted by what the patient does or does not do after leaving the office. Therefore, wound care instructions should be clear, detailed, and provided in both oral and written form. Information should also be provided about what to expect as the wound heals.

A trial of povidone-iodine in the prevention of infection in sutured lacerations

A prospective, randomized study of 500 consecutive emergency department patients with traumatic lacerations requiring sutures was performed comparing use of topical 1% povidone-iodine (Betadine) and scrubbing with wound management by irrigation with normal saline without scrubbing. A 60-second wound irrigation and scrub with a 1% povidone-iodine solution was the only difference in treatment between the two groups. Data relating to risk factors such as age; degree of contamination; type of closure; ethanol intoxication; mechanism of injury; and bone, joint, or tendon involvement were analyzed. Wounds were classified as clean, infected, or purulent at follow-up examination. One hundred five patients were lost to follow-up. Of the 395 remaining patients, 122 were contacted by phone and were classified based on their description of the wound; 273 were classified at reexamination in the ED. Of 201 povidone-iodine group wounds, 11 became infected; two of them (5.4%) were purulent. Of 194 control wounds, 30 became infected, of which 12 (15.46%) were purulent (P less than .01). These data suggest that use of a topical 1% povidone-iodine solution in traumatic lacerations prior to suturing reduces the incidence of wound infections.

Prophylaxis of post-appendicectomy sepsis by metronidazole and ampicillin: a randomized, prospective and double-blind trial

Two hundred and eighty-three patients were admitted to a randomized, prospective and double-blind trial of the effect of the addition of ampicillin to metronidazole in the prophylaxis of post-appendicectomy wound sepsis. Nineteen out of 142 patients in the metronidazole and ampicillin group developed wound sepsis compared with 33 out of 141 patients in the metronidazole group. The difference is statistically significant. Early cases, including normal, acutely inflamed and gangrenous appendices, received 2 doses of antibiotics. In late cases with perforation and abscess formation, the antibiotics were continued for 1 week. The difference in wound infection in each of these 2 subgroups was also statistically significant. The commonest organisms isolated from the appendicular fossa and the infected wounds were Escherichia coli and Bacteroides fragilis.

A survey of clinical trials of antibiotic prophylaxis in colon surgery: evidence against further use of no-treatment controls

To evaluate the use of antibiotics given prophylactically of colon surgery, we examined 26 trials published from 1965 to 1980 in which patients given various antibiotic regiments were compared with controls given no antibiotic treatment. In 22 (85 per cent of these trials) antibiotics reduced postoperative wound infection (p less than 0.05 in 14). Combining the results of the trials published from 1965 to 1975 reveals a 95 per cent confidence interval from the true difference in infection rates of 14 +/- 6 per cent (36 per cent for control group vs. 22 per cent for treatment group) and the true difference in death rates of 6.7 +/- 4.4 per cent (11.2 per cent for control group vs 4.5 per cent for treatment group). Yet trials employing control groups given no treatment continue to be reported. Since the use of such controls is justified only when no effective alternative therapy exists, we believe that any further trials of antibiotic prophylaxis in colon surgery should employ a previously proved standard. However, steadily increasing efficacy of treatment means that comparisons of new therapies with standard therapies will become prohibitively expensive because of the large number of patients required.

Randomized, prospective trial of topical hydrogen peroxide in appendectomy wound infection. High risk factors

Two hundred seventeen patients were admitted to a randomized and prospective trial of the use of topical hydrogen peroxide prophylactically against wound infection after appendectomy through a gridiron incision. One hundred nine patients received topical hydrogen peroxide and 108 patients were in the control group. There was no statistically significant difference in the wound infection rates in the two groups. Risk factors found to be associated with a significantly higher wound infection rate were (1) age greater than 40 years, (2) duration of symptoms of over 36 hours, (3) generalized guarding, tenderness or rebound, (4) state of the appendix at operation, (5) serous or purulent peritoneal effusion, (6) subjective difficulty of operation as assessed by the surgeons, and (7) positive bacterial culture from the appendicular fossa.

Wound healing: a review. II. Environmental factors affecting wound healing

A variety of factors, both intrinsic and extrinsic, may influence the healing of wounds. Some of these influences are environmental in nature and subject to advantageous manipulation by the practitioner. In this article, the role of humidity, temperature, infection and oxygen tension on the process of wound healing will be discussed.

Prevention of wound sepsis in gastro-intestinal surgery

After gastro-intestinal operations wound infection is usually caused by the inoculation of bacteria present within the intestinal tract into the incision during the surgical procedure. In theory, wound sepsis may be minimized by the following methods: (a) avoiding intestinal contamination of the incision; (b) altering the normal flora of the intestinal tract by adding oral antimicrobials to bowel preparation; (c) using topical or systemic prophylactic antibiotic administration for certain high-risk patients. The relative importance of these methods of prophylaxis is described.

Controlled trial of prophylactic antibiotics in minor wounds requiring suture

Minor wounds presenting in the accident department requiring suture were randomly allocated to one of three treatment groups: an intramuscular injection of 1-25 megaunits of penicillin as a long-acting depot preparation, local wound irrigation with 100mg of tetracycline in solution, or no antibiotics. All wounds had a standard surgical toilet and were closed under aseptic conditions. Wound infections were noted five to seven days after suture, and in the two groups receiving antibiotics 23% of the wounds were infected whilst in the control group the frequency was 7%. The wisdom of using routine antibiotic prophylaxis in minor wounds is questioned.