Topical antimicrobial toxicity

What We Leave Behind In Root Canals After Endodontic Treatment: Some Issues and Concerns

The benefits of using sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) as endodontic irrigants, and calcium hydroxide as an inter-appointment medicament, are well known to dentists. Many steps undertaken during endodontic treatment and retreatment are rather mechanical in nature, and less attention is committed to understanding the biological issues underlying endodontic treatment and retreatment. It should be noted that dentine is the fundamental substrate in endodontic treatment, and its properties and characteristics are the key determinant of nearly all disease and post-disease processes in the teeth. In this article the effects and counter-effects of NaOCl and EDTA on root canal dentine, and some other related issues are reviewed. This information will enable clinicians to use the beneficial effects of these chemicals, while necessary steps are considered to reduce their harmful effects on dentine substrate.

Wound Healing in the Veterinary Rehabilitation Patient

Wound healing is a biologically complex cascade of predictable overlap-ping events and is a natural restorative response to tissue injury. The biologic process for wound healing is the same for all wounds, although the specific mechanisms may vary. This article reviews the wound heal-ing process, discussing factors that may delay normal healing progression and potential modalities and treatments to aid healing.

Can povidone-iodine solution be used safely in a spinal surgery?

Intra-operative incidental contamination of surgical wounds is not rare. Povidone-iodine solution can be used to disinfect surgical wounds. Although povidone-iodine is a good broad-spectrum disinfecting agent, it has occasionally been reported to have a negative effect on wound healing and bone union. Therefore, its safety in a spinal surgery is unclear. A prospective, single-blinded, randomized study was accordingly conducted to evaluate the safety of povidone-iodine solution in spinal surgeries. Ascertained herein was the effect of wound irrigation with diluted povidone-iodine solution on wound healing, infection rate, fusion status and clinical outcome of spinal surgeries.

MATERIALS AND METHODS

From January 2002 to August 2003, 244 consecutive cases undergoing primary instrumented lumbosacral posterolateral fusion due to degenerative spinal disorder with segmental instability had been collected and randomly divided into two groups: the study group (120 cases, 212 fusion levels) and the control group (124 cases, 223 fusion levels). Excluded were those patients with a prior spinal surgery, spinal trauma, malignant tumor, infectious spondylitis, rheumatoid arthritis, ankylosing spondylitis, metabolic bone disease, skeletal immaturity or with an immunosuppressive treatment. In the former group, wounds were irrigated with 0.35% povidone-iodine solution followed by normal saline solution just before the bone-grafting and instrumentation procedure. However, only with normal saline solution in the latter. All the operations were done by the same surgeon with a standard technique. All the patients were treated in the same postoperative fashion as well. Later on, wound healing, infection rate, spinal bone fusion and clinical outcome were evaluated in both groups.

RESULTS

A significant improvement of back and leg pain scores, modified Japanese Orthopedic Association function scores (JOA) and ambulatory capacity have been observed in both groups. One hundred and seven patients in the study group and one hundred and nine in the control group achieved solid union. There was no infection in the study group but six deep infections in the control group. Wound dehiscence was noted in one group 1 and two group 2 patients. A subsequent statistical analysis revealed higher infection rate in the control group (P<0.05), but no significant difference in fusion rate, wound healing, improvement of pain score, function score and ambulatory capacity between the two groups.

CONCLUSION

Diluted povidone-iodine solution can be used safely in spinal surgeries, and it will not influence wound healing, bone union and clinical outcome.

Pathophysiology and Current Management of Burn Injury

PURPOSE

To provide the physician and registered professional nurse with an overview of the pathophysiology and current management of burn injuries.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses with an interest in learning about evidence-based prevention and management of burn wounds.

OBJECTIVES

After reading the article and taking the test, the participant should be able to: (1) Explain the pathophysiology of skin function. (2) Describe the different types of burn injuries. (3) Identify the treatment strategies for burn injuries.

Factors that affect equine wound repair

The rate and outcome of wound healing are determined by many factors,some of which are already in effect when the horse is first presented to the veterinarian. A thorough understanding of wound healing principles,coupled with clear client communication, should enable the practitioner to minimize the number of additional factors that may exacerbate the initial situation.

Exploring debridement options for chronic venous leg ulcers

The presence of devitalized tissue in a wound is a common problem facing practitioners and is regarded by many as a major inhibitory factor in the wound-healing process and can act as a focus for microbial proliferation. Therefore, for wound healing to proceed in a logical and ordered fashion, it follows that any necrotic material should be cleared from the wound bed. Wound bed preparation is now recognized as crucial to facilitating ordered restoration and regeneration of damaged tissue. However, there is a clear lack of good clinical evidence to support available wound debridement options, particularly for chronic ulcers of the lower extremities. This article reviews the debridement options available to practitioners and discusses rationales for treatment and implications for clinical practice with specific reference to chronic venous leg ulcer management.

A randomized clinical trial comparing hydrocolloid, phenytoin and simple dressings for the treatment of pressure ulcers [ISRCTN33429693]

Background

Pressure sores are important and common complications of spinal cord injury. Many preventive and therapeutic approaches have been tried and new trials are evolving. One relatively recent method is application of a hydrocolloid dressing (HD). In this study we compared the therapeutic effects of HD on pressure ulcer healing with two other topical applications, phenytoin cream (PC) and simple dressing (SD).

Methods

Ninety-one stage I and stage II pressure ulcers of 83 paraplegic male victims of the Iran-Iraq war were randomly allocated to three treatment groups. Mean age and weight of the participants were 36.64 ± 6.04 years and 61.12 ± 5.08 kg, respectively. All the patients were managed in long term care units or in their homes for 8 weeks by a team of general practitioners and nurses, and the ulcer status was recorded as "Complete healing", "Partial healing", "Without improvement" and "Worsening".

Results

Complete healing of ulcers, regardless of location and stage, was better in the HD group than the PC [23/31(74.19%) vs 12/30(40%); difference: 34.19%, 95% CI = 10.85–57.52, (P < 0.01)] or the SD [23/31(74.19%) vs 8/30(26.66%); difference: 47.53%, 95% CI = 25.45–69.61, (P < 0.005)] groups. Complete healing of stage I ulcers in the HD group [11/13(85%)] was better than in the SD [5/11(45%); difference: 40%, 95% CI = 4.7–75.22, (P < 0.05)] or PC [2/9 (22%); difference: 63%, 95% CI = 29.69–96.3, (P < 0.005)] groups. Complete healing of stage II ulcer in the HD group [12/18 (67%)] was better than in the SD group [3/19(16%); difference: 51%, 95% CI = 23.73–78.26, (P < 0.005)], but not significantly different from the PC group [10/21 (48%); difference: 19%, 95% CI = -11.47–49.47, (P > 0.05)]. We performed a second analysis considering only one ulcer per patient (i.e. 83 ulcers in 83 patients). This "per patient" analysis showed that complete ulcer healing in the HD group was better than in the PC [20/28(71.4%) vs 11/28 (39.3%); difference: 32.1%, 95% CI = 7.4–56.7, (P < 0.01)] or SD [20/28(71.4%) vs 8/27 (29.6%); difference: 41.8%, 95% CI = 17.7–65.8, (P < 0.005)] groups.

Conclusion

We deduced that HD is the most effective method investigated for treating stage I and II pressure ulcers in young paraplegic men.

Impact of antiseptics on radical metabolism, antioxidant status and genotoxic stress in blood cells: povidone-iodine versus octenidine dihydrochloride

No sufficient data are available of the of antiseptics' influence on human blood cells. Effects of two antiseptics, povidone-iodine (PVD-I) versus octenidine dihydrochloride (OD), were tested on antioxidant status, radical formation, antioxidant defence enzymes and genotoxic stress in blood cells, in vitro. Human blood was taken by venipuncture, enriched with PVD-I or OD (0.0001-20% final concentration) and incubated at 37 degrees C between 30 and 120 min. alpha-Tocopherol was assessed in erythrocytes and granulocytes. Superoxide-dismutase (SOD) and glutathione (GSH) were determined in erythrocytes, the total anti-oxidative capacity (TAC) and malondialdehyde (MDA) in their ghosts. In granulocytes status of hydrogen peroxide (H(2)O(2)), superoxide anions and MDA was observed. Genotoxic stress was determined by counting sister chromatide exchanges (SCE) in lymphocytes after enrichment within 0.05-0.4% of antiseptics. Based on all biomarker tested, concentrations up to 0.05% incubated for 30 min did not affect cell metabolism. 1% and 10% PVD-I reduced the activity of SOD (-40%), GSH (-62%) and the content of alpha-tocopherol more than OD (p<0.05). No significant differences between the antiseptics were observed for TAC and MDA. H(2)O(2) and superoxide anions were significantly reduced after the 10% addition for both substances independent on the exposure. Without having changes in lipid oxidation, the reduction of antioxidative defence mechanisms must be due to the oxidation caused by the antiseptics, mainly PVD-I. An increased SCE rate was neither observed with PVD-I nor with OD within an enrichment with 0.05-0.4%. Higher concentrations (1% and more) could not be tested on SCE formation because they caused cell bursts. The results presented indicate that concentrations up to 0.05% incubated for 30 min are safe for exposing blood cells of healthy subjects.

Treatment of field water with sodium hypochlorite for surgical irrigation

BACKGROUND

Early irrigation and surgical debridement of high-energy wounds and open fractures effectively prevents infection. Rapid wound care has been maximized by the United States military's "forward surgical teams." However, the volume of sterile irrigant required to treat multiple patients with multiple wounds presents a significant logistical burden. Using ground-derived field water could eliminate this burden.

METHODS

We collected 100 water samples from five sources. An initial bacterial count (CFU/mL) was determined before treatment. 5% sodium hypochlorite was then added to each sample to derive a concentration of 0.025%. After treatment, a final bacterial colony count was performed.

RESULTS

We found no bacterial growth in 99/100 samples. One post-treatment sample grew a single colony of a Bacillus species not present in the pretreatment culture and was determined to be an air contaminant.

CONCLUSIONS

Our field-expedient modification of Dakin's solution could substitute for sterile irrigation fluid when it is neither available nor logistically feasible.

A review of mechanical adjuncts in wound healing: hydrotherapy, ultrasound, negative pressure therapy, hyperbaric oxygen, and electrostimulation

Chronic or non-healing wounds may develop in the setting of many diseases and are the source of considerable morbidity as well as health costs. These wounds demand an aggressive, multifactorial approach including surgical debridement, revascularization, antibiotics and dressings. In addition several adjuvant treatment methods have been developed to further stimulate healing. Whirlpool, although used frequently, has not been proven to be of benefit. However, pulsed lavage does show a promising future. Ultrasound has demonstrated beneficial effects but further controlled studies are needed. Subatmospheric pressure therapy is associated with few complications and is fast becoming a mainstay of adjuvant therapy. Hyperbaric oxygen therapy has been shown to be effective for many types of wounds. Unfortunately, cost and access to chambers may prohibit its use on a routine basis. Finally, electrostimulation may be one of the up and coming therapies for the future. Though, more studies are needed to determine the mode of delivery for various types of wounds.

Wound bed preparation: a systematic approach to chronic wounds

'Wound bed preparation' is a current 'buzz phrase' in tissue viability and chronic wound management, but the majority of practitioners are uncertain what it actually means. This article summarizes the content of a series of study days recently given around the UK by a panel of experts in wound management. It discusses the meaning of the phrase 'wound bed preparation' and offers an acronym - TIME - that practitioners may find useful in their daily treatment of chronic wounds.

Wound dressings

There are currently hundreds of dressings on the market to aid in wound management. Before selecting a dressing for a particular wound, a practitioner must assess carefully the needs of the wound to understand which dressing would provide maximal benefit. Frequently, there is not one clear best choice, and it is crucial that the pros and cons of each dressing modality be understood. This article has provided a framework to assist in dressing assessment.

The fungicidal activity of novel nanoemulsion (X8W60PC) against clinically important yeast and filamentous fungi

Surfactant nanoemulsions are water in oil preparations that proved to have a broad spectrum biocidal activity against a variety of microorganisms including Gram-positive and Gram-negative bacteria, spores and enveloped viruses. These preparations are non-toxic to the skin, mucous membrane and gastrointestinal tissues at biocidal concentrations. In this study, 0.1% of the nanoemulsion designated X8W60PC has shown fungicidal activity against yeast including Candida albicans and C. tropicalis in 15 minutes. C. tropicalis was more sensitive than C. albicans, which required a longer time or a higher concentration of the nanoemulsion to achieve killing. Neutral to slightly alkaline pH was more effective in killing the yeast cells than acidic pH. Using the minimum inhibitory concentration assay, 0.08% of the nanoemulsion was inhibitory to C. albicans, and parapsilosis and filamentous fungi including Microsporum gypseum, Trichophyton mentagrophytes, Trichophyton rubrum, Aspergillus fumigatus and Fusarium oxysporum. None of the individual ingredients was as effective a fungicidal as the nanoemulsion at equivalent concentration. This shows that the nanoemulsion structure is an important factor in the anti-fungal activity. The X8W60PC has great potential as a topical anti-fungal agent and further investigation into the mechanism of fungicidal action is warranted.

Salvage therapy of open, infected surgical wounds: a retrospective review using Techni-Care

OBJECTIVE

To determine outcome of infected surgical wounds treated with 3% para-chloro-meta-xylenol + 3% phospholipid PTC [PCMX-PL] (Techni-Care).

DESIGN

Retrospective review of patient records.

SETTING

University hospital.

PATIENTS

Thirty consecutively treated patients (sixteen male, fourteen female) who had developed open infected wounds (twenty-one abdominal [seventy percent], nine extremity [thirty percent]). Mean patient age was 50.1 years. All wounds were treated with commonly practiced wound care techniques (e.g., debridement, frequent dressing changes using saline or topical antibiotics, and, in most cases, parenteral antibiotics) for an extended period of time prior to intervention (mean = 35 days).

INTERVENTIONS

PCMX-PL, a topical microbicide, was used as adjunctive therapy. Eight outcome parameters were analyzed: (1) patient morbidity and mortality; (2) wound healing; (3) number of debridements; (4) wound culture results; (5) leukocytosis (peripheral white blood cell count > 10,000 cells/microl); (6) number of febrile days (temperature > 101 degrees F); (7) length of hospital stay; and (8) number of days of intensive care.

RESULTS

No treatment failures or adverse reactions to PCMX-PL were seen. Twenty (sixty-seven percent) wounds were healed or had been successfully closed while ten (thirty-three percent) were granulating well at sixty-day follow-up. The number of debridements, positive wound cultures, white-blood-cells, and febrile days decreased after PCMX-PL treatment began.

CONCLUSIONS

Despite severe underlying diseases, all patients were discharged from the hospital with closed or healing wounds. We recommend treatment with PCMX-PL as an adjunctive therapy for infected wounds particularly when standard care measures have failed.

Use of elemental iodine for shunt infection prophylaxis

OBJECTIVE

Elemental iodine (I(2)) can kill a broad spectrum of organisms, including bacteria, fungi, and viruses. Furthermore, it is inexpensive, bacterial resistance is unknown, and allergic reactions are rare. Because of these properties, we wanted to determine the concentration of I(2) that would kill Staphylococcus epidermidis and Staphylococcus aureus without causing injury to the central nervous system, in an attempt to further reduce the rates of shunt infections.

METHODS

Bacterial kill studies using S. epidermidis and S. aureus were performed by using Ringer's lactate solution alone or solution containing I(2) at a concentration of 5, 10, 20, 50, 100, or 1000 parts per million (ppm), cefazolin at 1 mg/ml, or bacitracin at 100 units/ml. Twenty-one adult male Wistar rats, in seven groups, underwent a frontoparietal craniectomy. The surfaces of their brains were irrigated for 1 hour with Ringer's lactate solution alone or solution containing I(2) (at the concentrations noted above). After 72 hours of observation, the animals were killed. Their brains were then fixed in formalin, stained with hematoxylin/eosin, and examined.

RESULTS

Even with exposure of only 15 seconds to an I(2) solution of 20 ppm, no growth was detected with an inoculum of either bacteria of 100 million. In contrast, the two antibiotics were not nearly as effective as I(2), with kill rates ranging from 19 to 93%. Examination of the rat brains demonstrated no histological changes after subarachnoid exposure to solutions containing 5, 10, 20, or 50 ppm; however, necrosis was observed with concentrations of 100 and 1000 ppm.

CONCLUSION

I(2) can be added to irrigation solutions in sufficient concentrations to be bactericidal without causing any central nervous system injury.

Treatment of infected wounds with the antimicrobial peptide D2A21

BACKGROUND

Infected wounds impose a significantly negative effect on patient care and recovery, as infection hinders normal wound healing, resulting in increased patient morbidity and mortality. More attention is being focused on addressing the problem of multidrug-resistant bacteria and the staggering costs and consequences resulting from this. Recently, newly evaluated antimicrobial peptides have been shown to be active against a wide variety of bacteria in in vitro studies. This study evaluates the use of a particular antimicrobial peptide, D2A21 (Pittsburgh, PA), to combat infection in an acutely infected wound model.

METHODS

Forty-eight Wistar rats were used to compare the effects of D2A21 to control vehicle, silver sulfadiazine (SSD), and Sulfamylon in this model. Two 1.5 x 1.5-cm full-thickness defects were created on the rat dorsum and were subsequently inoculated with 108 Pseudomonas aeruginosa. Animals underwent daily treatment with either D2A21 gel, control vehicle, SSD, or Sulfamylon. Animals were evaluated for survival differences.

RESULTS

Survival analysis at 21 days for the different treatment groups were as follows: 100% for the D2A21-treated animals, 50% for control-treated animals, 83% for Sulfamylon-treated animals, and 33% for SSD-treated animals.

CONCLUSION

D2A21 antimicrobial peptide demonstrates significant activity compared with controls and standards of therapy. The promising effect of this topical peptide is clearly evident as shown by this study, and its further investigation as a potential agent in the fight against infected or chronic wounds is warranted.

[Treatment of the burned patient: a review of the literature]

This study aimed at describing, by means of a literature review, the topical agents and bandage types which have been recommended in the treatment of burns and their implications in nursing care. This study was conducted by collected bibliographic data concerning the last 12 years from Lilacs, Medline and Dedalus databases. The articles found were organized as research and review articles and later categorized according to the theme: topical agents and temporarily skin dressing. We discussed the possible effects as well as the indications and recommendations as to the manipulation of the agents and bandage types which have been recommended in the treatment of burns.

The use of povidone-iodine in superficial partial-thickness burns

Infection is of primary concern to those practitioners treating burns patients, as it is one of the primary complications associated with acute wounds and particularly with superficial partial-thickness burns. In the fight to reduce the risks, many practitioners deploy common antimicrobials agents prophylactically to help reduce risks, e.g. povidone-iodine. This review will examine the evidence to support this practice. The deployment of povidone-iodine in wound care is highly controversial, with questions being raised concerning not only the effectiveness of the product but also its safety and effect on wound healing. The use of povidone-iodine has been investigated both in vitro and in vivo, resulting in conflicting and often contradictory results. Of the work completed to date, researchers have failed to identify or control for extraneous variables which makes it difficult to compare and interpret research findings. The potential benefits or harm that the use of povidone-iodine may elicit in acute wounds is yet to be established.

[Iodine intoxication after subcutaneous irrigations of povidone iodine]

Irrigation of povidone iodine considered as a safe and effective procedure, is frequently used for deep infections. We report a case of intoxication by iodine in a man of 68-year-old after subcutaneous irrigations of Betadine at a concentration of 20% for a subcutaneous infection of the thigh. Abnormalities of cardiac conduction, lactic acidosis, acute renal failure, hypocalcaemia and thyroid dysfunction were the manifestations of the intoxication confirmed by a very high level of total blood iodine and urine iodine.

Pressure ulcer education: a pilot study of the knowledge and clinical confidence of geriatric fellows

OBJECTIVE

To assess the educational experiences of geriatric fellows on the subject of pressure ulcers and to begin validation of a survey that assesses pressure ulcer content knowledge of physicians in training.

DESIGN

Pilot study using a prospective survey.

PARTICIPANTS

42 geriatric fellows in New York State.

MAIN OUTCOME MEASURES

Likert scale ranking for self-reported feeling of preparation to manage geriatric patients with pressure ulcers and to teach other clinicians about the subject; knowledge test scores using a multiple choice, single-best-answer format.

RESULTS

Geriatric fellows in New York State who participated in the survey felt "adequately" prepared to lead a team and teach about pressure ulcers. Sixty-nine percent reported having teaching responsibilities. Sources of information included bedside rounds (79%), nurses (71%) lectures (67%), textbooks (67%), and geriatric attendings (60%). Educational settings were nursing homes (86%) and hospital units (64%). Forty-eight percent of geriatric fellows surveyed correctly identified the Braden Scale as a screening tool. Sixty-seven percent identified a description of a Stage I pressure ulcer and 52% identified a description of a Stage IV pressure ulcer. The mean score on the knowledge test for the cohort was 58 +/- 18% (SD) correct (range, 20% to 80%); the range for the fellowship programs was 36% to 62% correct.

CONCLUSIONS

Geriatric fellows need to improve their knowledge and confidence with regard to pressure ulcer care to become competent as clinicians and educators for this condition. Specific curricular guidelines and a validated knowledge assessment instrument on pressure ulcers are needed to improve the educational effectiveness of a geriatrics fellowship.

Community infection control: what is the evidence?

Evidence-based practice is the conscientious use of current best evidence in decision-making about care or the delivery of health services (National Institute for Public Health, 1996). Evidence-based health care is one aspect of the quality improvement activities of clinical governance as a main component of the programme of quality in the NHS (Hek, 2000). Practitioners working in clinical areas are therefore being required to deliver care that has been shown to be effective. (Playle, 2000).

Antiseptic wick: does it reduce the incidence of wound infection following appendectomy?

The role of prophylactic antibiotics is well established for contaminated wounds, but the use of antiseptic wound wicks is controversial. The aim of this work was to study the potential use of wound wicks to reduce the rate of infection following appendectomy. This prospective randomized controlled clinical trial was conducted at a university hospital in the department of surgery. The subjects were patients undergoing appendectomy for definite acute appendicitis. They were randomized by computer to primary subcuticular wound closure or use of an antiseptic wound wick. For the latter, ribbon gauze soaked in povidone-iodine was placed between interrupted nylon skin sutures. Wicks were soaked daily and removed on the fourth postoperative day. All patients received antibiotic prophylaxis. They were reviewed while in hospital and 4 weeks following operation for evidence of wound infection. The main outcome measures were wound infection, wound discomfort, and cosmetic result. The overall wound infection rate was 8.6% (15/174). In patients with wound wicks it was 11.6% (10/86) compared to 5.6% (5/88) in those whose wounds were closed by subcuticular sutures (p = NS). We concluded that the use of wound wicks was not associated with decreased wound infection rates following appendectomy. Subcuticular closure is therefore appropriate in view of its greater convenience and safety.

In vivo efficacy of antimicrobe-impregnated saline-filled silicone implants

Bacterial colonization of mammary implants is a prelude to clinical infection and has been implicated in the etiology of capsular contracture. Antimicrobial impregnation of a variety of medical devices with the combination of minocycline and rifampin has recently emerged as a potentially effective method for preventing device colonization and device-related infection. The objective of this animal study was to examine in vivo the antimicrobial efficacy of minocycline/rifampin-impregnated, saline-filled silicone implants. A rabbit model of Staphylococcus aureus colonization and infection of subcutaneously placed implants was used. A total of 48 saline-filled silicone implants (24 antimicrobe-impregnated and 24 control unimpregnated implants) were suspended in a 106 colony-forming units/ml bacterial suspension of S. aureus for 30 minutes at room temperature, allowed to dry for 60 minutes, and then implanted subcutaneously in the back of 12 rabbits (two antimicrobe-impregnated and two control implants were placed in each rabbit). Rabbits were monitored daily, then killed either at 2 weeks (10 rabbits) or at 4 weeks (two rabbits) and cultured. The antimicrobe-impregnated implants were 12 times less likely to be colonized than control unimpregnated implants (two of 24 versus 23 of 24; p < 0.001), and they were a significantly less likely cause of implant-related infection (0 of 24 versus 22 of 24; p < 0.001) and implant-related abscess (0 of 24 versus 21 of 24; p < 0.001) than control implants. The minocycline/rifampin-impregnated implants routinely demonstrated zones of inhibition against S. aureus at the time of explantation. These results indicate that minocycline/rifampin-impregnated implants can significantly decrease the rate of bacterial colonization, implant-related infection, and implant-related abscess. Antimicrobe-impregnated implants also have the potential of reducing the likelihood of capsular contracture.

Cytotoxicity mechanisms of sodium hypochlorite in cultured human dermal fibroblasts and its bactericidal effectiveness

We investigated the therapeutic efficacy of the topical antiseptic sodium hypochlorite (NaOCl) for antibacterial activity and in parallel the cytotoxicity mechanisms by which hypochlorite and the chloramines generated therefrom induce oxidative tissue damage, which further influences the wound-healing process. Human dermal fibroblasts were exposed to increasing concentrations of reagent NaOCl (0.00005-0.1%) at exposure times varying between 2 and 24 h and the protective effects of fetal calf serum (FCS) determined. Antibacterial power was studied by testing a wide range of hypochlorite concentrations (0.00025-0.5%) against four isolated bacterial species. Total bactericidal effects were observed only for 0.5%; concentration range 0.25-0.025% produced partial antimicrobial activity. The early NaOCl-produced cytotoxic action on cultured fibroblasts was cell ATP depletion which occurred at 0.00005% (with FCS 2%) followed by dose- and time-dependent decreases, reaching levels below 5% of control values. Using the 3'-[1-(phenylamino-carbonyl)-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene sulfonic acid metabolic assay to evaluate cell death, we observed that NaOCl concentrations greater than 0.05% provoked null fibroblast survival at all exposure times assayed. Hypochlorous acid proved to exert a rapid inhibitory effect on DNA synthesis, consistent with its primary role in bacterial killing by phagocytes. Cytotoxicity produced by increasing NaOCl concentrations and assessed by measuring both mitochondrial function and cell DNA synthesis was reduced with the greatest presence of FCS (10%) in culture media.

Slow release iodine preparation and wound healing: in vitro effects consistent with lack of in vivo toxicity in human chronic wounds

BACKGROUND

Antiseptic agents, particularly slow-release preparations, are increasingly being used in the management of chronic wounds. One such agent, cadexomer iodine, carries iodine (0.9% weight/weight) immobilized in beads of dextrin and epichlorhydrin and has been demonstrated to be highly effective in promoting healing of exudative wounds. However, there have been no studies directly assessing the potential lack of toxicity of cadexomer iodine on human cutaneous tissues.

OBJECTIVES

To determine if, within a certain concentration range, cadexomer iodine is non-toxic to human cells and cutaneous tissue and to assess histologically human chronic exudative wounds that are being treated with cadexomer iodine.

METHODS

We examined the effects of varying concentrations of cadexomer iodine on the viability of human fibroblasts in culture (by trypan blue exclusion). The morphology, cellular proliferation capacity (measured by [3H]thymidine uptake), ability to produce alpha 1(I) procollagen chain mRNA, and cell outgrowth from neonatal foreskin explants were also evaluated in human fibroblasts after incubation with various concentrations of cadexomer iodine. Moreover, biopsies of chronic exudative wounds concurrently treated with cadexomer iodine were stained with haematoxylin and eosin or a Gram stain and evaluated microscopically.

RESULTS

At concentrations of up to 0.45%, cadexomer iodine was found to be non-toxic to fibroblasts in vitro; there were no changes in viability, morphology, cellular proliferation, ability to produce collagen, and cell outgrowth from explants. In vivo, skin biopsies of chronic exudative wounds being treated with cadexomer iodine demonstrated no evidence of cell necrosis, displayed re-epithelialization, and revealed bacteria within the cadexomer beads.

CONCLUSIONS

These studies demonstrate that cadexomer iodine has definite non-toxic concentration ranges for fibroblasts in vitro, which are consistent with a lack of cellular toxicity in human chronic exudative wounds treated with cadexomer iodine. Cadexomer iodine may also have the additional property of trapping microorganisms.

Efficacy of antimicrobial-impregnated silicone sections from penile implants in preventing device colonization in an animal model

OBJECTIVES

To assess, in an animal study, the efficacy of minocycline/rifampin-impregnated silicone sections of pump bulbs from penile implants in preventing device colonization by Staphylococcus aureus. Infection constitutes a very serious complication of penile implants.

METHODS

Minocycline/rifampin-impregnated and control silicone pump bulb sections from penile implants were each inoculated with about 10(3) to 10(4) colony-forming units of S. aureus. After 8 hours of incubation with bacteria at room temperature, the test devices were allowed to dry for 30 minutes, and then subcutaneously implanted in the backs of rabbits. Eleven rabbits each received a total of six devices. The wounds were sutured, and the rabbits were monitored daily, then killed at 2 days after surgery. In vitro zones of inhibition against S. aureus by the minocycline/rifampin-impregnated and control devices were also determined.

RESULTS

All of the six tested antimicrobial-impregnated devices but none of the control devices produced zones of inhibition in vitro against S. aureus (mean zone of inhibition by antimicrobial-impregnated devices of 23 mm). The antimicrobial-impregnated devices retrieved from rabbits were sixfold less likely than were the control devices to be colonized with S. aureus (2 [6%] of 33 versus 11 [33%] of 33, respectively; P = 0.011).

CONCLUSIONS

The results of this animal study indicate that minocycline/rifampin-impregnated pump bulb sections from penile implants provide antimicrobial activity in vitro against S. aureus and protect against staphylococcal colonization of devices implanted for 2 days in animals.

Estudo comparativo entre diversos tipos de tratamento para peritonite fecal em rato

OBJETIVO: A peritonite é responsável por aproximadamente 50% das mortes por sepse e, apesar de avanços nos métodos usados para o seu diagnóstico e tratamento, cerca de um terço dos pacientes ainda morre de peritonite secundária grave. O objetivo do presente trabalho foi comparar a eficácia de diversos tipos de tratamento para a peritonite fecal grave e estabelecida. MÉTODOS: Foram usadas 40 ratas adultas, submetidas à peritonite fecal com injeção intraperitoneal de uma suspensão de fezes de ratos. Os animais foram divididos em oito grupos (n = 5): Grupo 1, controle; Grupo 2, limpeza mecânica intraperitoneal com gaze; Grupo 3, lavagem com solução salina a 0,9%, à temperatura ambiente; Grupo 4, lavagem com solução salina a 0,9%, a 37,8ºC; Grupo 5, lavagem com povidona-iodo a 0,5%; Grupo 6, lavagem com clorexidina a 0,05%; Grupo 7, injeção intramuscular de gentamicina e clindamicina; Grupo 8, introdução intraperitoneal de açúcar. RESULTADOS: Os grupos 5 e 8 foram os que apresentaram a mortalidade mais rápida (menos de 24 horas). Após 72 horas, permaneceu viva uma rata em cada um dos grupos 2, 3, 4 e 6. Nos grupos 1, 5, 7 e 8 não houve sobrevida. Apesar de todos os animais do Grupo 7 morrerem, o óbito ocorreu em um período mais longo (72 horas) do que o dos demais grupos. CONCLUSÃO: Somente ocorreu sobrevida nos grupos submetidos à limpeza peritoneal menos agressiva. Além disso, um procedimento terapêutico único de limpeza ou antibiótico sistêmico por um dia não é suficiente para prevenir a morte em ratos com peritonite fecal grave e estabelecida.

Improving the treatment of leg ulcers

Treatment of leg ulcers is often inadequate, with delayed diagnosis, overuse of antibiotics, and insufficient or inadequate use of compression therapy. Ulcers caused by arterial insufficiency will not heal unless the blood flow is improved. Ulcers caused by venous insufficiency will usually heal within a few months with appropriate compression therapy. Compression can be applied with stockings, bandages, or a pump. Class 2 compression stockings are required for treatment of ulcers; TED stockings and Class 1 stockings do not provide adequate compression. A four-layer compression bandage can be used if a patient cannot manage stockings. Applying the bandage with the correct pressure is a skill developed from practice. A pump can be used if neither stockings nor bandages are suitable. However, it must be used for six hours a day, which precludes use by active patients. An ulcer that does not heal with three months of adequate compression therapy requires further investigation.

The role of povidone-iodine in podiatric chronic wound care

This review examines the problems and limitations of existing studies into povidone-iodine, and suggests that the product should be used carefully in the management of the diabetic foot.

An in vivo comparison of topical agents on wound repair

Selection of the ideal antiseptic or antimicrobial treatment for contaminated wounds remains a controversial decision. Clinical decisions are often made on the basis of in vitro studies and personal preference. Although topical solutions are widely used, their comparative in vivo effects on wound healing are largely unreported.A porcine wound model was used to compare five commonly used topical agents-5% mafenide acetate (Sulfamylon solution), 10% povidone with 1% free iodine (Betadine), 0.25% sodium hypochlorite ("half-strength" Dakin), 3% hydrogen peroxide, and 0.25% acetic acid-with a control group. Reepithelialization, angiogenesis, neodermal regeneration, fibroblast proliferation, collagen production, and bacterial colony counts were analyzed at 4 and 7 days after wounding (n = 4). Reepithelialization was not significantly influenced among the various treatment modalities tested. Sulfamylon and Dakin solutions significantly increased neodermal thickness (p < 0.05), whereas hydrogen peroxide and acetic acid significantly inhibited neodermal formation (p < 0.001). All treatments except hydrogen peroxide significantly increased fibroblast proliferation. Sulfamylon and Betadine significantly enhanced angiogenesis (p < 0.05). Sulfamylon proved most effective in maintaining an aseptic environment while concomitantly increasing angiogenesis, fibroblast proliferation, and dermal thickness compared with control. These data show that selection of a particular topical treatment can affect various aspects of wound repair in an animal model. These results suggest that the selection of topical treatments in the clinical setting should be carefully tailored to match unique wound situations and therapeutic endpoints.

Corneal endothelial cytotoxicity of diluted povidone--iodine

PURPOSE

To assess corneal endothelial toxicity of diluted povidone-iodine (PI) in vivo and in vitro.

SETTING

Cell Biology Laboratory and the Laboratory for Intraocular Microsurgery and Implants, Goldschleger Eye Research Institute, Sackler School of Medicine, Tel-Aviv University, Chaim Sheba Medical Center, Tel-Hashomer, Israel.

METHODS

In an in vitro study, cultured bovine corneal endothelial cells were exposed to diluted PI. The degree of cell damage was determined by staining with trypan blue and by comparing the results to those in a control group. In an in vivo study, a single dose of diluted PI was injected into the anterior chamber of rabbit eyes, completely replacing the aqueous humor. The eyes were evaluated by clinical examination, specular microscopy, pachymetry, pneumotonometry, and histopathology and compared to a control group injected with a balanced salt solution.

RESULTS

In vitro, PI concentrations of 0.05% or less did not induce endothelial cell damage. Significant damage was observed with a PI concentration of 0.1%. Calf serum concentrations of 1% and higher in the culture media protected the endothelial cell monolayer from cytotoxic damage by PI. Aqueous humor did not have a similar effect. In vivo, PI concentrations of 0.1% or less did not induce changes in corneal endothelium morphology or function as assessed by specular microscopy and pachymetry. A PI concentration of 1% served as a positive control, causing corneal edema and endothelial cell loss as demonstrated by pachymetry, histopathology, and elevated intraocular pressure.

CONCLUSIONS

The concentrations of PI tolerated by animal endothelium in vitro and in vivo were higher than the reported bactericidal levels. These findings justify further investigation of the safety and efficacy of PI for intracameral prophylaxis during surgery.

Issues and dilemmas in the prevention and treatment of pressure ulcers: a review

Considerable dogma and rhetoric, rather than evidence-based results, have accompanied recommendations for the prevention and treatment of pressure ulcers. Therapy for pressure ulcers is generally empiric, based on anecdotal experience, or borrowed from the treatment of patients with acute wounds. The treatment of pressure ulcers is problematic because of multiple comorbidities of patients, the chronic duration of pressure ulcers, and often by the physician's relative unfamiliarity with treatment options. Issues and dilemmas in the prevention of pressure ulcers center around risk assessment, means of pressure relief, and nutritional support. Similar issues in the treatment of pressure ulcers include implementing pressure relief, nutritional support, local wound care, the best method of debridement, diagnosing infection, the use of topical growth factors, and surgical treatment. The accumulating data for the prevention and management of pressure ulcers permits an outline of clinical strategies.

Treatment of pressure ulcers in a rehabilitation ward

This article presents a case study of a patient transferred to a rehabilitation unit for elderly people. The aim of the article is to show that, with a dynamic and committed multidisciplinary team approach, the prevention and treatment of difficult pressure ulcers can be achieved in an ever increasingly frail elderly population. The article will discuss the methods used to treat and tackle the challenges that staff encounter when treating these patients.

Chronic venous insufficiency and venous leg ulceration

Venous ulcers are the most common form of leg ulcers. Venous disease has a significant impact on quality of life and work productivity. In addition, the costs associated with the long-term care of these chronic wounds are substantial. Although the exact pathogenic steps leading from venous hypertension to venous ulceration remain unclear, several hypotheses have been developed to explain the development of venous ulceration. A better understanding of the current pathophysiology of venous ulceration has led to the development of new approaches in its management. New types of wound dressings, topical and systemic therapeutic agents, surgical modalities, bioengineered tissue, matrix materials, and growth factors are all novel therapeutic options that may be used in addition to the "gold standard," compression therapy, for venous ulcers. This review discusses current aspects of the epidemiology, pathophysiology, clinical presentation, diagnostic assessment, and current therapeutic options for chronic venous insufficiency and venous ulceration. (J Am Acad Dermatol 2001;44:401-21.)

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be familiar with the 3 main types of lower extremity ulcers and should improve their understanding of the epidemiology, pathogenesis, risk factors, clinical presentation, diagnostic assessment, and current therapies for chronic venous insufficiency and venous ulcers.

An effective approach for preventing and treating gastrostomy tube complications in newborns

Gastrostomy tube site complications can be difficult to manage and may temporarily prevent use of the tube for feeding. Such complications are especially common in premature newborns. Lcakage is the usual cause of tube-site complications. This makes maintenance of effective intragastric and transabdominal tube seals the most effective approach for preventing and treating tube-site complications in newborns. This article explains how to use balloon volume and transabdominal segment length to recognize problems that can lead to leakage and how to correct these problems before they cause complications. It also addresses skin care at the site.

THE PIG AS A MODEL FOR HUMAN WOUND HEALING

The medical literature describes numerous in vitro and in vivo wound-healing models. The selection of an animal model depends on a number of factors including availability, cost, ease of handling, investigator familiarity, and anatomical/functional similarity to humans. Small mammals are frequently used for wound healing studies, however, these mammals differ from humans in a number of anatomical and physiological ways. Anatomically and physiologically, pig skin is more similar to human skin. The many similarities between man and pig would lead one to believe that the pig should make an excellent animal model for human wound healing. The purpose of this paper is to review the existing literature for evidence of this supposition and determine how well the various models correlate to human wound healing. Studies of wound dressings, topical antimicrobials, and growth factors are examined. Over 180 articles were utilized for this comparative review. Our conclusion is that the porcine model is an excellent tool for the evaluation of therapeutic agents destined for use in human wounds.

A novel surfactant nanoemulsion with a unique non-irritant topical antimicrobial activity against bacteria, enveloped viruses and fungi

A novel non-ionic surfactant nanoemulsion designated 8N8 has been tested for its biocidal activity. One percent 8N8 produced effective bactericidal activity against Bacillus cereus, Bacillus subtilis, Haemophilus influenzae, Neisseria gonorrhoeae, Streptococcus pneumoniae, and Vibrio cholerae in 15 minutes. In contrast, most enteric gram-negative bacteria were resistant to 8N8. One percent 8N8 was also virucidal within 15 minutes for all tested enveloped viruses, including Herpes simplex type 1, influenza A and vaccinia viruses. One percent 8N8 also demonstrated fungistatic activity on Candida albicans. The rapid and non-specific inactivation of vegetative bacteria and enveloped viruses, in addition to its fungistatic activity and low toxicity in experimental animals, makes 8N8 a potential candidate for use as a topical biocidal agent.

Wound management in postacute care

Decreasing hospital length of stay has dictated that postacute and long-term care facilities bear the brunt of treating acute and chronic wounds. Two types of chronic wounds are discussed: (1) pressure ulcers and (2) diabetic ulcers. The differential diagnosis of these ulcers is imperative because the management of both types of wound differs substantially. Wound therapy includes relieving pain, correcting nutritional deficiencies, maintaining an optimal wound environment, shielding the wound from further damage, removing necrotic debris, promoting granulation tissue formation, protecting against bacterial contamination, choosing an appropriate dressing, and surgical treatment. The application of these principles is discussed, and the differences among wound types are highlighted.

Wound dressing with sustained anti-microbial capability

To overcome current limitations in wound dressings for treating mustard-burn induced septic wound injuries, a nonadherent wound dressing with sustained anti-microbial capability has been developed. The wound dressing consists of two layers: the upper layer is a carboxymethyl-chitin hydrogel material, while the lower layer is an anti-microbial impregnated biomaterial. The hydrogel layer acts as a mechanical and microbial barrier, and is capable of absorbing wound exudate. In physiological fluid, the carboxymethylated-chitin hydrogel swells considerably, imbibing up to 4 times its own weight of water and is also highly porous to water vapor. The moisture permeability of the dressing prevents the accumulation of fluid in heavily exudating wounds seen in second-degree burns. The lower layer, fabricated from chitosan acetate foam, is impregnated with chlorhexidine gluconate. From the in vitro release studies, the loading concentration was optimized to deliver sufficient anti-microbial drug into the wound area to sustain the anti-microbial activity for 24 h. The anti-microbial activity of the dressing against Pseudomonas aeruginosa and Staphylococcus aureus was tested using the Bauer-Kirby Disk Diffusion Test.

Neonatal skin care

The relative importance of neonatal health and neonatal skin care has been highlighted in recent years as infant mortality rates have decreased while death rates during the neonatal period remain unacceptably high in many areas of the world. During the neonatal period, many newborns develop preventable, clinically apparent skin problems, and many more, especially preterm neonates, experience morbidity caused by compromised skin barrier integrity. Several strategies are available for protecting the integrity and promoting the hygiene of the skin and augmenting its function as a barrier to TEWL and heat loss and the entrance of infectious or toxic agents. Research defining optimal applications of many of these strategies, however, and the development of new approaches in skin care is one of the greatest challenges in pediatric dermatology and holds promise for improving neonatal outcome in the future. The ability to modulate epidermal barrier function and integrity relies largely on the topical use of protective materials and substances and manipulation of the external environment. As understanding of epidermal barrier development advances, perhaps pharmacologic manipulation of barrier development, as now practiced for augmentation of neonatal lung maturity, will become a reality. In the meantime, greater awareness among neonatal health care practitioners of state-of-the-art strategies for optimizing skin integrity in neonates is an important step toward improving neonatal health.

Fads and fancies

The selection of wound-care dressings should be based on clinical evidence. In reality, purchasing decisions are too often influenced by company marketing campaigns and current trends, says Helena Baxter

Promoting wound healing in the neonatal setting: process versus protocol

The principles of wound healing have been studied and evaluated extensively in the animal and human adult models. Practical application has been long in coming to the neonatal and critical care settings. Neonatal nurses have the ability to significantly affect the outcome of wound healing through the care they provide and the approaches that they take to caring for wounds. The article reviews pertinent literature to provide an evidence base for optimal wound care activities. An outcome-oriented, functional approach to product selection is described to help nurses meet the goals of protection, cleansing, moist wound healing, and appropriate dressing and care of wounds specific to the neonatal population.

Updates in wound management for the pediatrician

Lacerations are common in children, and skills in wound management, especially laceration repair, are important. The minimization of pain and anxiety should be considered an essential part of the procedure. Newer techniques using topical anesthetics and tissue adhesives have significantly simplified the process of laceration repair promoting application in office, clinic, and emergency department settings. In situations inappropriate for topical anesthesia and closure, the use of buffered lidocaine and attention to the technique of infiltration are important. Although infection is the most common complication, the percentage of lacerations, which become infected in children, is low. Antibiotic prophylaxis is seldom needed. Human and animal bites raise special concerns in the assessment for primary repair and prophylactic antibiotic use.

Neonatal skin care: the scientific basis for practice

OBJECTIVE

To review the literature addressing the care of neonatal skin.

DATA SOURCES

Computerized searches in MEDLINE and CINAHL, as well as references cited in articles reviewed. Key concepts in the searches included neonatal skin differences; neonatal skin and care practices for skin integrity; neonatal skin and toxicity; permeability; and contact irritant sensitization.

STUDY SELECTION

Articles and comprehensive works relevant to key concepts and published after 1963, with an emphasis on new findings from 1993 to 1999. One hundred two citations were identified as useful to this review.

DATA EXTRACTION

Data were extracted and organized under the following headings: anatomy and physiology of the skin; physiologic and anatomic differences in neonatal skin; nutritional deficiencies; skin care practices; and care of skin breakdown.

DATA SYNTHESIS

Newborns' skin is at risk for disruption of normal barrier function because of trauma. In light of available evidence about differences in neonatal skin development, clinical practice guidelines are suggested for baths, lubrication, antimicrobial skin disinfection, and adhesive removal. In addition, basic care practices are suggested for maintaining skin integrity, reducing exposure to potentially toxic substances, and promoting skin health beyond the neonatal period. Preventive care recommendations are made for reducing trauma, protecting the skin's immature barrier function, and promoting skin integrity.

CONCLUSIONS

This review generated evidence with which to create a new and comprehensive practice guideline for clinicians. Evaluation of the guideline is under way at 58 U.S. sites.