Comparison of silver sulphadiazine 1 per cent, silver sulphadiazine 1 per cent plus chlorhexidine digluconate 0.2 per cent and mafenide acetate 8.5 per cent for topical antibacterial effect in infected full skin thickness rat burn wounds

Review of History of Basic Principles of Burn Wound Management

Thermal energy is an essential and useful resource to humans in modern society. However, a consequence of using heat carelessly is burns. Burn injuries have various causes, such as exposure to flame, radiation, electrical, and chemical sources. In this study, we reviewed the history of burn wound care while focusing on the basic principles of burn management. Through this review, we highlight the need for careful monitoring and customization when treating burn victims at each step of wound care, as their individual needs may differ. We also propose that future research should focus on nanotechnology-based skin grafts, as this is a promising area for further improvement in wound care.

2.5% Mafenide Acetate: A Cost-Effective Alternative to the 5% Solution for Burn Wounds

Mafenide acetate is an antimicrobial agent used to decrease the bacterial load for burn wounds. The 5% solution is more commonly used yet double the cost of its 2.5% counterpart. This study aims to evaluate outcomes and cost associated with the use of 2.5 vs 5% mafenide acetate formulation in the adult burn population. Adult patients (≥18 years) receiving 2.5% mafenide acetate during an 11-month period between 2014 and 2015, corresponding to a policy change in favor of the use of 2.5% mafenide acetate, were queried. Historical controls, patients receiving 5% mafenide acetate, were also reviewed during an 11-month period between 2013 and 2014. A retrospective review was performed comparing wound infection rate, bacteremia, sepsis, pneumonia, duration of mafenide therapy, length of hospital stay, mortality, and cost. A total of 54 and 65 patients received 2.5 and 5% mafenide acetate, respectively. There was no difference in wound infection, bacteremia, sepsis, pneumonia, duration of treatment, and mortality between the two groups. No adverse events occurred in either group directly related to mafenide. Candida and Staph species were the two most common isolates in the 2.5% group, whereas Pseudomonas and Staph species were the most common in the 5% arm. The mean cost of 2.5% mafenide therapy was $1494.92 compared with $3741.39 for 5% mafenide acetate. The 2.5% concentration demonstrates to be an equally efficacious and cost-effective alternative to the 5% concentration. Burn centers should consider the use of the more dilute preparation for burn wound infection prophylaxis as it may reduce the cost without compromising patient safety.

Use of silver in the prevention and treatment of infections: silver review

BACKGROUND

The use of silver for the treatment of various maladies or to prevent the transmission of infection dates back to at least 4000 b.c.e. Medical applications are documented in the literature throughout the 17th and 18th centuries. The bactericidal activity of silver is well established. Silver nitrate was used topically throughout the 1800 s for the treatment of burns, ulcerations, and infected wounds, and although its use declined after World War II and the advent of antibiotics, Fox revitalized its use in the form of silver sulfadiazine in 1968.

METHOD

Review of the pertinent English-language literature.

RESULTS

Since Fox's work, the use of topical silver to reduce bacterial burden and promote healing has been investigated in the setting of chronic wounds and ulcers, post-operative incision dressings, blood and urinary catheter designs, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. The beneficial effects of silver in reducing or preventing infection have been seen in the topical treatment of burns and chronic wounds and in its use as a coating for many medical devices. However, silver has been unsuccessful in certain applications, such as the Silzone heart valve. In other settings, such as orthopedic hardware coatings, its benefit remains unproved.

CONCLUSION

Silver remains a reasonable addition to the armamentarium against infection and has relatively few side effects. However, one should weigh the benefits of silver-containing products against the known side effects and the other options available for the intended purpose when selecting the most appropriate therapy.

Intra-Abdominal Placement of Antimicrobial-Impregnated Mesh is Associated with Noninfectious Fever

The antimicrobial, silver/chlorhexidine, when impregnated on mesh has been demonstrated to resist mesh infection in in vitro and in vivo models. The clinical, human systemic response to intraperitoneal placement of silver/chlorhexidine-impregnated mesh has not been investigated to date. Between October 2002 and November 2004, all in-patients undergoing laparoscopic ventral hernia repair were retrospectively analyzed. All repairs used expanded polytetraflouroethylene (ePTFE) Dual Mesh (DM) or ePTFE impregnated with silver/chlorhexidine, Dual Mesh Plus (DM+). Patient demographics, hernia characteristics, mesh type, operative details, and hospital course data were collected. Noninfectious fevers were defined as a temperature greater than 100.4 F without an identified source. Standard statistical methods were used. During the 2-year study period, 120 patients underwent laparoscopic ventral hernia repair (DM = 55, DM+ = 65). The two groups were similarly matched in terms of age, body mass index, American Society of Anesthesiologists score, defect size, and mesh size. Postoperative fever without an identified source occurred in 10 (18.2%) patients with DM and in 25 (38.5%) patients using DM+ (P = 0.015). A multivariant analysis revealed that only mesh type and body mass index predicted postoperative fever. All fevers resolved within the first 72 hours in the DM patients; however, 16 per cent of the DM+ group had persistent fevers of unknown origin after 72 hours. Within the DM+ group, patients with postoperative fevers had significantly longer postoperative stays (4.8 days vs 3.0 days; P = 0.009). The use of antimicrobial-impregnated ePTFE mesh with silver/chlorhexidine in laparoscopic ventral hernia repair is associated with noninfectious postoperative fever. In our patients, the evaluation and management of these fevers resulted in a significantly longer hospital stay.

Comparison of Battlefield-Expedient Topical Antimicrobial Agents for the Prevention of Burn Wound Sepsis in a Rat Model

Topical antimicrobial therapy has the potential to limit the mortality and morbidity of contaminated battlefield injuries. Many agents available are ill-suited for use on the battlefield; however, mafenide acetate solution (MAS) has known efficacy as a burn dressing adjunct, and previous work with mafenide as a direct chemotherapeutic has shown promise. A total of 71 male Sprague-Dawley rats underwent a 20% TBSA full-thickness scald. Wounds were inoculated with a solution containing 1 x 10 colony-forming units per milliliter of Pseudomonas aeruginosa 1244 (ATCC 27317). Treatments with 10% mafenide acetate cream (MAC), 5% MAS, 5% mafenide hydrochloride solution (MHS), and 4% chlorhexidine gluconate solution (CHG) were established. Agents were applied directly to the wound daily for 10 days. Animals were monitored for 21 days and euthanized if they manifested a moribund state as a result of sepsis. Survival to study completion in the negative control group (no treatment) was 25% (3/12). Survival in the positive control group (MAC) was 100%. None of the test agent groups demonstrated significant survival over the untreated controls; MAS resulted in 5/12 (42%) survival (P = .67), CHG in 4/12 (33%) survival (P = 1.0), and MHS resulted in 2/12 (17%) survival (P = 1.0). There were no significant differences in group weights on day 1. By day 6, all test agent groups were significantly underweight compared with the MAC group. This trend resolved as underweight animals died. We did not demonstrate significant prevention of wound sepsis with these agents as we used them. These techniques should not be substituted for established burn care. Aqueous direct topical antimicrobial agents have logistical advantages over creams and dressing soaks for field use, and the search for a battlefield-expedient agent for use at or near the point of wounding should continue.

Cytotoxicity of topical antimicrobial agents used in burn wounds in Australasia

BACKGROUND

Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical antimicrobial agents has helped improve the survival of these patients. Silvazine (Sigma Pharmaceuticals, Melbourne, Australia) (1% silver sulphadiazine and 0.2% chlorhexidine digluconate) is used exclusively in Australasia, and there is no published study on its cytotoxicity. This study compared the relative cytotoxicity of Silvazine with 1% silver sulphadiazine (Flamazine (Smith & Nephew Healthcare, Hull, UK)) and a silver-based dressing (Acticoat (Smith & Nephew Healthcare, Hull, UK)).

METHODS

Dressings were applied to the centre of culture plates that were then seeded with keratinocytes at an estimated 25% confluence. The plates were incubated for 72 h and culture medium and dressings then removed. Toluidine blue was added to stain the remaining keratinocytes. Following removal of the dye, the plates were photographed under standard conditions and these digital images were analysed using image analysis software. Data was analysed using Student's t-test.

RESULTS

In the present study, Silvazine is the most cytotoxic agent. Seventy-two hour exposure to Silvazine in the present study results in almost no keratinocyte survival at all and a highly statistically significant reduction in cell survival relative to control, Acticoat and Flamazine (P<0.001, P<0.01, P<0.01, respectively). Flamazine is associated with a statistically significant reduction in cell numbers relative to control (P<0.05), but is much less cytotoxic than Silvazine (P<0.005).

CONCLUSION

In this in-vitro study comparing Acticoat, Silvazine and Flamazine, Silvazine shows an increased cytotoxic effect, relative to control, Flamazine and Acticoat. An in-vivo study is required to determine whether this effect is carried into the clinical setting.

An in vitro study of the anti-microbial efficacy of a 1% silver sulphadiazine and 0.2% chlorhexidine digluconate cream, 1% silver sulphadiazine cream and a silver coated dressing

Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical anti-microbial agents has helped improve the survival in these patients. There are a number of anti-microbials available, one of which, Silvazine (1% silver sulphadiazine (SSD) and 0.2% chlorhexidine digluconate), is used only in Australasia. No study, in vitro or clinical, had compared Silvazine with the new dressing Acticoat. This study compared the anti-microbial activity of Silvazine, Acticoat and 1% silver sulphadiazine (Flamazine) against eight common burn wound pathogens.

METHODS

Each organism was prepared as a suspension. A 10 microl inoculum of the chosen bacterial isolate (representing approximately between 10(4) and 10(5) total bacteria) was added to each of four vials, followed by samples of each dressing and a control. The broths were then incubated and 10 microl loops removed at specified intervals and transferred onto Horse Blood Agar. These plates were then incubated for 18 hours and a colony count was performed.

RESULTS

The data demonstrates that the combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine) results in the most effective killing of all bacteria. SSD and Acticoat had similar efficacies against a number of isolates, but Acticoat seemed only bacteriostatic against E. faecalis and methicillin-resistant Staphylococcus aureus. Viable quantities of Enterobacter cloacae and Proteus mirabilis remained at 24h.

CONCLUSION

The combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine) is a more effective anti-microbial against a number of burn wound pathogens in this in vitro study. A clinical study of its in vivo anti-microbial efficacy is required.

Silver. I: Its antibacterial properties and mechanism of action

Silver products have two key advantages: they are broad-spectrum antibiotics and are not yet associated with drug resistance. This article, the first in a two-part series, describes the main mechanism of action of this metallic element.

Antibacterial mesh sling: a prospective outcome analysis

OBJECTIVES

To prospectively assess the outcome results of the Gore-Tex antibacterial mesh sling in women with pelvic prolapse and stress incontinence.

METHODS

Between July 1997 and November 1998, 30 women with stress incontinence and vaginal prolapse underwent vaginal reconstruction with the antibacterial mesh sling. All patients had documented stress incontinence by preoperative urodynamic evaluation. Postoperatively, we conducted an outcome analysis on the basis of the results from a self-reported satisfaction questionnaire, a detailed pelvic examination, a cough stress test, and the Q-tip test. Urodynamic studies were performed on patients with persistent stress incontinence or urge symptoms. Cystoscopy was performed on patients suspected of having urethral erosion.

RESULTS

Complete follow-up was available for all 30 patients. Of the group, 12 (40.0%) of 30 underwent implantation of the antibacterial mesh sling alone and 18 (60.0%) underwent additional prolapse repair. The mean follow-up was 18 months (range 9 to 24); mean age was 58 years (range 29 to 87). Stress incontinence was cured in 28 (93.3%) of 30 patients. De novo urge incontinence developed in 1 (5.2%) of 18 patients; urge symptoms persisted in 5 (41.7%) of 12 patients. The postoperative mean Valsalva Q-tip angle was 15 degrees (range 0 degrees to 25 degrees ). The incidence of urethral obstruction and erosion was zero. The mean postoperative pain score was 3 of 10 (range 0 to 6), and the mean satisfaction score was 9 of 10 (range 7 to 10). The mean time to discharge was 21 hours (range 6 to 29). All 30 women (100%) were willing to undergo surgery again.

CONCLUSIONS

The safety profile of the Gore-Tex antibacterial mesh is better than that of the conventional Gore-Tex sling. When meticulous surgical technique is used, excellent short-term results can be achieved in the correction of female stress incontinence.

The use of porphyrins for eradication of Staphylococcus aureus in burn wound infections

The assessment of deuteroporphyrin-hemin complex as an agent for the treatment of burn wounds infected with a multiple-drug resistant strain of Staphylococcus aureus was performed. The effect of the porphyrin on the survival of the infectious bacteria was first assayed in culture, and later tested as well in a burned infected animal model. The addition of deuteroporphyrin and hemin, separately or together (as a complex) to a growing culture of S. aureus was monitored during 8 hours. It was found that deuteroporphyrin alone was strongly bactericidal only after photosensitization. On the other hand, hemin alone was moderately bactericidal but light independent. A combination of both deuteroporphyrin and hemin was extremely potent even in the dark and did not require illumination to eradicate the bacteria. The in vivo experiments by application of the above porphyrins in combination to infected burn wounds in guinea pigs was an effective way to reduce dramatically the contaminating S. aureus. Reduction of more than 99% of the viable bacteria was noted after the porphyrin mixture was dropped on the eschar or injected into the eschar, an effect that lasted for up to 24 hours. The deuteroporphyrin-hemin complex may be suggested as a new bactericidal treatment of S. aureus infected burns since it was found to be a potent and promising anti-Staphylococcal agent.

Management of burn wounds with prompt excision and immediate closure

The past 30 years have been witness to significant improvements in the overall care and prognosis of those suffering burn trauma. At the heart of this success is an aggressive approach to burn wounds. This approach, which is detailed in this review, involves early operative removal of devitalized tissue and biological coverage of resultant wounds, with particular attention to wounds in specialized areas.